diff options
Diffstat (limited to 'old/65699-h/65699-h.htm')
| -rw-r--r-- | old/65699-h/65699-h.htm | 15060 |
1 files changed, 0 insertions, 15060 deletions
diff --git a/old/65699-h/65699-h.htm b/old/65699-h/65699-h.htm deleted file mode 100644 index 9cb24ee..0000000 --- a/old/65699-h/65699-h.htm +++ /dev/null @@ -1,15060 +0,0 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" - "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> -<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> - <head> - <meta http-equiv="Content-Type" content="text/html;charset=utf-8" /> - <meta http-equiv="Content-Style-Type" content="text/css" /> - <title> - The Project Gutenberg eBook of Life and Death, by A. Dastre. - </title> - <link rel="coverpage" href="images/cover.jpg" /> - <style type="text/css"> - -body { - margin-left: 10%; - margin-right: 10%; -} - -h1 -{ - margin-top: 2em; margin-bottom: 2em; - text-align: center; - font-size: x-large; - font-weight: normal; - line-height: 1.6; -} - - h2,h3,h4{ - text-align: center; - clear: both; - } - -.half-title { - margin-top: 2em; margin-bottom: 2em; - text-align: center; - font-size: x-large; - font-weight: normal; - line-height: 1.6; - } - -div.chapter {page-break-before: always;} -h3.nobreak {page-break-before: avoid;} - -/* Paragraphs */ - -p {text-indent: 1em; - margin-top: .75em; - text-align: justify; - margin-bottom: .75em; - } - -.psig {text-align: right; margin-right: 2em;} -.hang {text-align: justify; padding-left: 1.75em; text-indent: -1.75em;} -.prel {text-align: justify; padding-left: 1.75em; text-indent: -1.75em; - font-size: .8em;} - -.spaced {margin-top: 3em; margin-bottom: 3em;} - -hr { - width: 33%; - margin-top: 2em; - margin-bottom: 2em; - margin-left: 33.5%; - margin-right: 33.5%; - clear: both; -} - -hr.chap {width: 65%; margin-left: 17.5%; margin-right: 17.5%;} - -@media print { hr.chap {display: none; visibility: hidden;} } - -ul.index { list-style-type: none; } -li.ifrst { margin-top: 1em; } -li.indx { margin-top: .5em; } -li.isub1 {text-indent: 1em;} - -table { - margin-left: auto; - margin-right: auto; - } - -.standard { font-size: .9em; border-collapse: collapse; } -td {padding-left: 5px;} - -.trbig {line-height: 2em;} -.tdl {text-align: left;} -.tdr {text-align: right;} -.tdc {text-align: center;} -.tdrb {text-align: right; vertical-align: bottom;} -.tdlt {text-align: left; vertical-align: top;} -.tdh {text-align: justify; padding-left: 1.75em; - text-indent: -1.75em;} - -.pagenum { /* uncomment the next line for invisible page numbers */ - /* visibility: hidden; */ - position: absolute; - left: 92%; - font-size: smaller; - text-align: right; -} /* page numbers */ - -.blockquot { - margin-left: 5%; - margin-right: 10%; -} - - -.center {text-align: center;} - - -.smcap {font-variant: small-caps;} -.allsmcap { text-transform:lowercase; } - -.fs1 {font-size: 50%;} -.fs2 {font-size: 70%;} - - -/* Footnotes */ - - .footnotes {border: dashed 1px;} - - .footnote { - margin-left: 10%; - margin-right: 10%; - font-size: 0.9em; - } - -.footnote .label { - position: absolute; - right: 84%; - text-align: right; - } - -.fnanchor { - vertical-align: super; - font-size: .8em; - text-decoration: none; - white-space: nowrap - } - -/* Poetry */ - - -/* Poetry */ -.poetry-container {text-align: center;} -.poetry {text-align: left; margin-left: 5%; margin-right: 5%;} -/* uncomment the next line for centered poetry in browsers */ - .poetry {display: inline-block;} -.poetry .stanza {margin: 1em auto;} -.poetry .verse {text-indent: -3em; padding-left: 3em;} -/* large inline blocks don't split well on paged devices */ -@media print { .poetry {display: block;} } -.x-ebookmaker .poetry {display: block;} - - -/* Transcriber's notes */ - -.transnote { - background-color: #E6E6FA; - color: black; - font-size:smaller; - padding:0.5em; - margin-bottom:5em; - font-family:sans-serif, serif; - } - -/* Poetry indents */ -.poetry .indent0 {text-indent: -3em;} - - - </style> - </head> -<body> - -<div style='text-align:center; font-size:1.2em; font-weight:bold'>The Project Gutenberg eBook of Life and death, by Albert Dastre</div> - -<div style='display:block; margin:1em 0'> -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online -at <a href="https://www.gutenberg.org">www.gutenberg.org</a>. If you -are not located in the United States, you will have to check the laws of the -country where you are located before using this eBook. -</div> - -<p style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Title: Life and death</p> - -<div style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Author: Albert Dastre</div> - -<div style='display:block; margin-top:1em; margin-bottom:1em; margin-left:2em; text-indent:-2em'>Translator: William John Greenstreet</div> - -<div style='display:block; margin:1em 0'>Release Date: June 25, 2021 [eBook #65699]</div> - -<div style='display:block; margin:1em 0'>Language: English</div> - -<div style='display:block; margin:1em 0'>Character set encoding: UTF-8</div> - -<div style='display:block; margin-left:2em; text-indent:-2em'>Produced by: Turgut Dincer, Les Galloway and the Online Distributed Proofreading Team at https://www.pgdp.net</div> - -<div style='margin-top:2em; margin-bottom:4em'>*** START OF THE PROJECT GUTENBERG EBOOK LIFE AND DEATH ***</div> -<div class="transnote"> - -<h3>Transcriber’s Notes</h3> - -<p>Obvious typographical errors have been silently corrected. Variations -in hyphenation and accents have been standardised but all other -spelling and punctuation remains unchanged.</p> - -<p>In the section on The Instinct of Life, fifth paragraph “and <a href="#Flourens_has_reduced">Flourens -has reduced</a> the ratio to that of 5:1, which would still give us 120 -years.” the 120 has been corrected to 100.</p> - -<p>In Book V, Chapter III, Chemical Changes, “and at the same time would -transform an amido-group into an amido-group.” is as printed.</p> -</div> - -<p class="half-title">LIFE AND DEATH.</p> -<div class="chapter"></div> - - - - -<h1> -LIFE AND DEATH</h1> - -<p class="center spaced"><small>BY</small><br /> - -A. DASTRE,<br /> -<span class="fs1">PROFESSOR OF PHYSIOLOGY AT THE SORBONNE.</span></p> - -<p class="center spaced"><small>TRANSLATED BY</small><br /> -W. J. GREENSTREET, M.A., F.R.A.S.</p> - -<p class="center spaced"> -THE WALTER SCOTT PUBLISHING CO., LTD.,<br /> -<small>PATERNOSTER SQUARE, LONDON, E.C.</small><br /> -CHARLES SCRIBNER’S SONS,<br /> -<small>153-157 FIFTH AVENUE, NEW YORK.<br /> -1911</small><br /> -</p> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<h2 class="nobreak" id="PREFACE">PREFACE.</h2> -</div> - - -<p>The educated and inquiring public of the present -day addresses to the experts who have specialized -in every imaginable subject the question that was -asked in olden times of Euclid by King Ptolemy -Philadelphus, Protector of Letters. Recoiling in -dismay from the difficulties presented by the study -of mathematics and annoyed at his slow progress, he -inquired of the celebrated geometer if there was -not some royal road, could he not learn geometry -more easily than by studying the Elements. The -learned Greek replied, “There is no royal road.” -These royal roads making every branch of science -accessible to the cultivated mind did not exist in -the days of Ptolemy and Euclid. But they do -exist to-day. These roads form what we call -Scientific Philosophy.</p> - -<p>Scientific philosophy opens a path through the -hitherto inextricable medley of natural phenomena. -It throws light on facts, it lays bare principles, it -replaces contingent details by essential facts. And -thus it makes science accessible and communicable. -Intellectually it performs a very lofty function.</p> - -<p>There is virtually a philosophy of every science.<span class="pagenum" id="Page_vi">[Pg vi]</span> -There is therefore a philosophy of the science which -deals with the phenomena of life and death—<i>i.e.</i>, of -physiology. I have endeavoured to give a summary -of this philosophy in this volume. I have had in -view two classes of readers. In the first place there -are readers of general culture who are desirous of -knowing something of the trend of ideas in biology. -They already form quite a large section of the great -public.</p> - -<p>These scholars and inquirers, with Bacon, believe -that the only science is general science. What they -want to know is not what instruments we use, our -processes, our technique, and the thousand and one -details of the experiments on which we spend our -lives in the laboratory. What they are interested in -are the general truths we have acquired, the problems -we are trying to solve, the principles of -our methods, the progress of our science in the -past, its state in the present, its probable course in -the future.</p> - -<p>But I venture to think that this book is also -addressed to another class of readers, to those whose -professional study is physiology. To them it is -dedicated. They have been initiated into the -mysteries of the science. They are learning it by -practice. That is the right method. Practice makes -perfect. Claude Bernard used to say that in order -to be an expert in experimental science you must -first be “a laboratory rat.” And among us there are -many such “laboratory rats.” They are guided in<span class="pagenum" id="Page_vii">[Pg vii]</span> -the daily task of investigation by a dim instinct -of the path and of the direction of contemporary -physiology. Perhaps it may be of assistance to -them to find their more or less unconscious ideas -here expressed in an explicit form.</p> - -<p class="psig"> -A. DASTRE. -</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_ix">[Pg ix]</span></p> - -<h2 class="nobreak" id="CONTENTS">CONTENTS.</h2> -</div> - - -<table class="standard" summary=""> -<tr class="trbig"> -<td class="tdc" colspan="3"><a href="#BOOK_I">BOOK I</a>.</td> -</tr> -<tr> -<td class="tdh" colspan="3"><span class="smcap">The Frontiers of Science. General Theories of -Life and Death. Their Successive Transformations.</span></td> -</tr> -<tr> -<td class="tdl"><span class="fs2">CHAP.</span></td> -<td></td> -<td class="tdr"><span class="fs2">PAGE</span></td> -</tr> -<tr> -<td class="tdlt">I.</td> -<td class="tdh"><span class="smcap">Early Theories</span></td> -<td class="tdrb"><a href="#Page_1">1</a></td> -</tr> -<tr> -<td class="tdlt">II.</td> -<td class="tdh"><span class="smcap">Animism</span></td> -<td class="tdrb"><a href="#Page_5">5</a></td> -</tr> -<tr> -<td class="tdlt">III.</td> -<td class="tdh"><span class="smcap">Vitalism</span></td> -<td class="tdrb"><a href="#Page_15">15</a></td> -</tr> -<tr> -<td class="tdlt">IV.</td> -<td class="tdh"><span class="smcap">The Monistic Theory</span></td> -<td class="tdrb"><a href="#Page_34">34</a></td> -</tr> -<tr> -<td class="tdlt">V.</td> -<td class="tdh"><span class="smcap">The Emancipation of Scientific Research from -the Yoke of Philosophical Doctrine</span></td> -<td class="tdrb"><a href="#Page_42">42</a></td> -</tr> -<tr class="trbig"> -<td class="tdc" colspan="3"><a href="#BOOK_II">BOOK II</a>.</td> -</tr> -<tr> -<td class="tdh" colspan="3"><span class="smcap">The Doctrine of Energy and the Living World. -General Ideas of Life. Alimentary Life.</span></td> -</tr> -<tr> -<td class="tdlt">I.</td> -<td class="tdh"><span class="smcap">Energy in General</span></td> -<td class="tdrb"><a href="#Page_57">57</a></td> -</tr> -<tr> -<td class="tdlt">II.</td> -<td class="tdh"><span class="smcap">Energy in Biology</span></td> -<td class="tdrb"><a href="#Page_97">97</a></td> -</tr> -<tr> -<td class="tdlt">III.</td> -<td class="tdh"><span class="smcap">Alimentary Energetics</span></td> -<td class="tdrb"><a href="#Page_116">116</a></td> -</tr> -<tr> -<td class="tdc" colspan="3"><a href="#BOOK_III">BOOK III</a>.</td> -</tr> -<tr> -<td class="tdc" colspan="3"><span class="smcap">The Characters Common to Living Beings.</span></td> -</tr> -<tr> -<td class="tdlt">I.</td> -<td class="tdh"><span class="smcap">Doctrine of Vital Unity</span></td> -<td class="tdrb"><a href="#Page_146">146</a></td> -</tr> -<tr> -<td class="tdlt">II.</td> -<td class="tdh"><span class="smcap">Morphological Unity of Living Beings</span></td> -<td class="tdrb"><a href="#Page_157">157</a></td> -</tr> -<tr> -<td class="tdlt">III.</td> -<td class="tdh"><span class="smcap">Chemical Unity of Living Beings</span></td> -<td class="tdrb"><a href="#Page_173">173</a></td> -</tr> -<tr> -<td class="tdlt">IV.</td> -<td class="tdh"><span class="smcap">Twofold Conditions of Vital Phenomena. -Irritability</span></td> -<td class="tdrb"><a href="#Page_188">188</a> -<span class="pagenum" id="Page_x">[Pg x]</span></td> -</tr> -<tr> -<td class="tdlt">V.</td> -<td class="tdh"><span class="smcap">The Specific Form: its Acquisition, its Reparation</span></td> -<td class="tdrb"><a href="#Page_199">199</a></td> -</tr> -<tr> -<td class="tdlt">VI.</td> -<td class="tdh"><span class="smcap">Nutrition. Functional Assimilation. Functional -Distribution. Assimilating Synthesis</span></td> -<td class="tdrb"><a href="#Page_209">209</a></td> -</tr> -<tr class="trbig"> -<td class="tdc" colspan="3"><a href="#BOOK_IV">BOOK IV</a>.</td> -</tr> -<tr> -<td class="tdc" colspan="3"><span class="smcap">The Life of Matter.</span></td> -</tr> -<tr> -<td class="tdlt">I.</td> -<td class="tdh"><span class="smcap">Universal Life (Opinions of the Philosophers -and Poets). Continuity between Brute Bodies and Living Bodies. Origin of the Principle of -Continuity</span></td> -<td class="tdrb"><a href="#Page_239">239</a></td> -</tr> -<tr> -<td class="tdlt">II.</td> -<td class="tdh"><span class="smcap">Origin of Living Matter in Brute Matter</span></td> -<td class="tdrb"><a href="#Page_249">249</a></td> -</tr> -<tr> -<td class="tdlt">III.</td> -<td class="tdh"><span class="smcap">Organization and Chemical Composition of Living -Matter and Brute Matter</span></td> -<td class="tdrb"><a href="#Page_255">255</a></td> -</tr> -<tr> -<td class="tdlt">IV.</td> -<td class="tdh"><span class="smcap">Evolution and Mutability of Living Matter and -Brute Matter</span></td> -<td class="tdrb"><a href="#Page_259">259</a></td> -</tr> -<tr> -<td class="tdlt">V.</td> -<td class="tdh"><span class="smcap">The Composition of the Specific Form. Living -Bodies and Crystals. Cicatrization</span></td> -<td class="tdrb"><a href="#Page_281">281</a></td> -</tr> -<tr> -<td class="tdlt">VI.</td> -<td class="tdh"><span class="smcap">Nutrition in the Living Being and in the Crystal</span></td> -<td class="tdrb"><a href="#Page_290">290</a></td> -</tr> -<tr> -<td class="tdlt">VII.</td> -<td class="tdh"><span class="smcap">Generation in Brute Bodies and Living Bodies. -Spontaneous Generation</span></td> -<td class="tdrb"><a href="#Page_294">294</a></td> -</tr> -<tr class="trbig"> -<td class="tdc" colspan="3"><a href="#BOOK_V">BOOK V</a>.</td> -</tr> -<tr> -<td class="tdc" colspan="3"><span class="smcap">Senescence and Death.</span></td> -</tr> -<tr> -<td class="tdlt">I.</td> -<td class="tdh"><span class="smcap">The Different Points of View from which Death -may be regarded</span></td> -<td class="tdrb"><a href="#Page_307">307</a></td> -</tr> -<tr> -<td class="tdlt">II.</td> -<td class="tdh"><span class="smcap">Constitution of the Organisms. Partial Death. -Collective Deaths</span></td> -<td class="tdrb"><a href="#Page_312">312</a></td> -</tr> -<tr> -<td class="tdlt">III.</td> -<td class="tdh"><span class="smcap">Physical and Chemical Characteristics of -Cellular Deaths. Necrobiosis</span></td> -<td class="tdrb"><a href="#Page_321">321</a></td> -</tr> -<tr> -<td class="tdlt">IV.</td> -<td class="tdh"><span class="smcap">Apparent Perrennity of Complex Individuals</span></td> -<td class="tdrb"><a href="#Page_330">330</a></td> -</tr> -<tr> -<td class="tdlt">V.</td> -<td class="tdh"><span class="smcap">Immortality of the Protozoa and of Slightly -Differentiated Cells</span></td> -<td class="tdrb"><a href="#Page_334">334</a></td> -</tr> -<tr> -<td class="tdlt">VI.</td> -<td class="tdh"><span class="smcap">Lethality of the Metazoa and of Differentiated -Cells</span></td> -<td class="tdrb"><a href="#Page_340">340</a></td> -</tr> -<tr> -<td class="tdlt">VII.</td> -<td class="tdh"><span class="smcap">Man. The Instinct of Life and the Instinct of -Death</span></td> -<td class="tdrb"><a href="#Page_345">345</a></td> -</tr> -<tr> -<td></td> -<td class="tdh"><span class="smcap"><a href="#INDEX_OF_AUTHORS">Index</a></span></td> -<td class="tdrb"><a href="#Page_361">361</a></td> -</tr> -</table> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_1">[Pg 1]</span></p> - -<p class="half-title">LIFE AND DEATH.</p> - - -<h2 class="nobreak" id="BOOK_I">BOOK I.<br /> - - -<span class="hang"><small>THE FRONTIERS OF SCIENCE—GENERAL THEORIES -OF LIFE AND DEATH—THEIR SUCCESSIVE -TRANSFORMATIONS.</small></span></h2> - -<p class="prel">Chapter I. Early Theories.—II. Animism.—III. Vitalism.—IV. -Monism.—V. Emancipation of Scientific Research -from the Yoke of Philosophy.</p> -</div> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<h3 class="nobreak" id="CHAPTER_I">CHAPTER I.<br /> - -<small>EARLY THEORIES</small>.</h3> -</div> - -<p class="prel">Animism—Vitalism—The Physico-Chemical Theory—Their -Survival and Transformations.</p> - - -<p>The fundamental theories of science are but the expression -of its most general results. What, then, is -the most general result of the development of -physiology or biology—that is to say, of that department -of science which has life as its object? What -glimpse do we get of the fruit of all our efforts? The -answer is evidently the response to that essential -question—What is Life?</p> - -<p>There are beings which we call living beings; there -are bodies which have never been alive—inanimate -bodies; and there are bodies which are no longer<span class="pagenum" id="Page_2">[Pg 2]</span> -alive—dead bodies. The fact that we use these terms -implies the idea of a common attribute, of a <i>quid proprium</i>, -life, which exists in the first, has never existed -in the second, and has ceased to exist in the last. Is -this idea correct? Suppose for a moment that this -is so, that this implicit supposition has a foundation, -and that there really is something which corresponds -to the word “<i>life</i>.” Must we then wait for the last -days of physiology, and in a measure for its last -word before we know what is hidden behind this -word, “life”?</p> - -<p>Yes, no doubt positive science should be precluded -from dealing with questions of this kind, which are -far too general. It should be limited to the study of -second causes. But, as a matter of fact, scientific -men in no age have entirely conformed to this provisional -or definitive antagonism. As the human -mind cannot rest satisfied with indefinite attempts, or -with ignorance pure and simple, it has always asked, -and even now asks, from the spirit of system the -solution which science refuses. It appeals to philosophical -speculation. Now, philosophy, in order to -explain life and death, offers us hypotheses. It offers -us the hypotheses of thirty, of a hundred, or two -thousand years ago. It offers us animism; vitalism -in its two forms, unitary vitalism or the doctrine of -vital force, and dismembered vitalism or the doctrine -of vital properties; and finally, materialism, a -mechanical theory, unicism or monism,—to give it -all its names—<i>i.e.</i>, the physico-chemical doctrine of -life. There are, therefore, at the present day, in -biology, representatives of these three systems which -have never agreed on the explanation of vital -phenomena—namely, animists, vitalists, and monists.<span class="pagenum" id="Page_3">[Pg 3]</span> -But it is pretty clear that there must have been -some change between yesterday and to-day. Not -in vain has general science and biology itself made -the progress which we know has been made since -the Renaissance, and especially during the course -of the nineteenth century. The old theories have -been compelled to take new shape, such parts as have -become obsolete have been cut away, another -language is spoken—in a word, the theories have -become rejuvenated. The neo-animists of our day, -Chauffard in 1878, von Bunge in 1889, and more -recently Rindfleisch, do not hold exactly the same -views as Aristotle, St. Thomas Aquinas, or Stahl. -Contemporary neo-vitalists, physiologists like Heidenhain, -chemists like Armand Gautier, or botanists like -Reinke do not between 1880 and 1900 hold the same -views as Paracelsus in the fifteenth century and Van -Helmont in the seventeenth, as Barthez and Bordeu at -the end of the eighteenth, or as Cuvier and Bichat at -the beginning of the nineteenth century. Finally, the -mechanicians themselves, whether they be disciples -of Darwin and Haeckel, as most biologists of our -own time, or disciples of Lavoisier, as most physiologists -of the present day, have passed far beyond the -ideas of Descartes. They would reject the coarse -materialism of the celebrated philosopher. They -would no longer consider the living organism as a -machine, composed of nothing but wheels, springs, -levers, presses, sieves, pipes, and valves; or again -of matrasses, retorts, or alembics, as the iatro-mechanicians -and would-be chemists of other days -believed.</p> - -<p>All that is changed, at any rate in form. If we look -back only thirty or forty years we see that the old<span class="pagenum" id="Page_4">[Pg 4]</span> -doctrines have undergone more or less profound -modifications. The changes of form, which have been -made necessary by the acquisitions of contemporary -science, enable us to appreciate its progress. They -enable us to give an account of the progress of -biology, and for this reason they deserve to be -examined with some attention. It is into this -examination that I ask my readers to accompany me.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_5">[Pg 5]</span></p> - -<h3 class="nobreak" id="CHAPTER_II">CHAPTER II.<br /> - -<small>ANIMISM.</small></h3> -</div> - - -<p class="prel">The Common Characteristic of Animism and Vitalism: the -Human Statue—Primitive Animism—Stahl’s Animism—First -Objection with Reference to the Relation between -Soul and Body—Second Objection: the Unconscious -Character of Vital Operations—Twofold Modality of the -Soul—Continuity of the Soul and Life.</p> - - - -<p>Children are taught that there are three kingdoms -in Nature—the mineral kingdom and the two living -kingdoms, animal and vegetable. This is the whole -of the sensible world. Then above all that is placed -the world of the soul. School-boys therefore have -no doubts on the doctrines that we discuss here. -They have the solution. To them there are three -distinct spheres, three separate worlds—matter, life, -and thought.</p> - -<p>It is this preconceived idea that we are about to -examine. Current opinion solves <i>a priori</i> the question -of the fundamental homogeneity or lack of resemblance -of these three orders of phenomena—the -phenomena of inanimate nature, of living nature, and -of the thinking soul. <i>Animism</i>, <i>vitalism</i>, and <i>monism</i> -are, in reality, different ways of looking at them. -They are the different answers to this question:—Are -vital, psychic, and physico-chemical manifestations -essentially distinct? Vitalists distinguish be<span class="pagenum" id="Page_6">[Pg 6]</span>tween -life and thought, animists identify them. In -the opposite camp mechanicians, materialists, or -monists make the same mistake as the animists, but -to that mistake they add another: they assimilate the -forces at play in animals and plants to the general -forces of the universe; they confuse all three—soul, -life, inanimate nature.</p> - -<p>These problems belong on many sides to metaphysical -speculation. They have been discussed by -philosophers; they have been solved from time immemorial -in different ways, for reasons and by arguments -which it is not our purpose to examine here, -and which, moreover, have not changed. But on -some sides they belong to science, and must be tested -in the light of its progress. Cuvier and Bichat, for -example, considered that the forces in action in -living beings were not only different from physico-mechanical -forces, but were utterly opposed to them. -We now know that this antagonism does not exist.</p> - -<p>The preceding doctrines, therefore, depend up to a -certain point on experiment and observation. They -are subject to the test of experiment and observation -in proportion as the latter can give us information on -the degree of difference or analogy presented by -psychic, vital, and physico-chemical facts. Now, -scientific investigations have thrown light on these -points. There is no doubt that the analogies and -the resemblances of these three orders of manifestations -have appeared more and more numerous and -striking as our knowledge has advanced. Hence it is -that animism can count to-day but very few advocates -in biological science. Vitalism in its different forms -counts more supporters, but the great majority have -adopted the physico-chemical theory.</p> - -<p><span class="pagenum" id="Page_7">[Pg 7]</span></p> - -<p>Both animism and vitalism separate from matter a -directing principle which guides it. At bottom they -are mythological theories somewhat similar to the -paganism of old. The fable of Prometheus or the -story of Pygmalion contains all that is essential. -An immaterial principle, divine, stolen by the -Titan from Jupiter, or obtained from Venus by the -Cypriot sculptor, descends from Olympus and -animates the form, till then inert, which has been -carved in the marble or modelled in the clay. In a -word, there is a human statue. It receives a breath -of heavenly fire, a vital force, a divine spark, a soul, -and behold! it is alive. But this breath can also -leave it. An accident happens, a clot in a vein, a -grain of lead in the brain—the life escapes, and all -that is left is a corpse. A single instant has proved -sufficient to destroy its fascination. This is how all -men picture to their minds the scene of death. The -breath escapes; something flies away, or flows away -with the blood. The happy genius of the Greeks -conceived a graceful image of this, for they represented -the life or the soul in the form of a butterfly -(Psyche) leaving the body, an ethereal butterfly, -as it were, opening its sapphire wings.</p> - -<p>But what is this subtle and transient guest of the -human statue, this passing stranger which makes of -the living body an inhabited house? According to -the animists it is the soul itself, in the sense in -which the word is understood by philosophers; the -immortal and reasoning soul. To the vitalists it is -an inferior, subordinate soul; a soul, as it were, of -secondary majesty, the vital force, or in a word, life.</p> - -<p><i>Primitive Animism.</i>—Animism is the oldest and -most primitive of the conceptions presented to the<span class="pagenum" id="Page_8">[Pg 8]</span> -human mind. But in so far as it is a co-ordinated -doctrine, it is the most recent. In fact it only -received its definitive expression in the eighteenth -century, from Stahl, the philosopher-physician and -chemist.</p> - -<p>According to Tylor, one of the first speculations of -primitive man, of the savage, is as to the difference -between the living body and the corpse. The former -is an inhabited house, the latter is empty. To such -rudimentary intellects the mysterious inhabitant is a -kind of <i>double</i> or duplicate of the human form. It is -only revealed by the shadow which follows the body -when illuminated by the sun, by the image of its -reflection in the water, by the echo which repeats the -voice. It is only seen in a dream, and the figures -which people and animate our dreams are nothing -but these doubled, impalpable beings. Some savages -believe that at the moment of death the double, or -the soul, takes up its residence in another body. -Sometimes each individual possesses, not one of these -souls, but several. According to Maspero, the -Egyptians counted at least five, of which the -principle, the <i>ka</i> or <i>double</i>, would be the aeriform or -vaporous image of the living form. Space is peopled -by souls on their travels, which leave one set of bodies -to occupy another set. After having been the cause -of life in the bodies which they animated, they -react from without on other beings, and are the -cause of all sorts of unexpected events. They are -benevolent or malevolent spirits.</p> - -<p>Analogy inevitably leads simple minds to extend -the same ideas to animals and plants; in a word, to -attribute souls to everything alive, souls more or less -nomadic, wandering, or interchangeable, as is taught<span class="pagenum" id="Page_9">[Pg 9]</span> -in the doctrine of metempsychosis. Mons. L. Errera -points out that this primitive, co-ordinated, hierarchized -doctrine—meet subject for the poet’s art—is -the basis of all ancient mythologies.</p> - -<p><i>The Animism of Stahl.</i>—Modern animism was -much more narrow in scope. It was a medical theory—<i>i.e.</i> -almost exclusive to man. Stahl had adopted it -in a kind of reaction against the exaggerations of the -mechanical school of his time. According to him, the -life of the body is due to the intelligent and reasoning -soul. It governs the corporeal substance and -directs it towards an assigned end. The organs are -its instruments. It acts on them directly, without -intermediaries. It makes the heart beat, the muscles -contract, the glands secrete, and all the organs perform -their functions. Nay more, it is itself the -architectonic soul, which has constructed and which -maintains the body which it rules. It is the <i>mens -agitat molem</i> of Virgil.</p> - -<p>It is remarkable that these ideas, so excessively -and exaggeratedly spiritualistic, should have been -brought forward by a chemist and a physician, while -ideas completely opposed to these were admitted by -philosophers like Descartes and Leibniz, who were -decided believers in the spirituality of the soul. Stahl -had been Professor of Medicine at the University of -Halle, physician to the Duke of Saxe-Weimar, and -later to the King of Prussia. He left an important -medical and chemical work, both theoretical and -practical. He is the author of the celebrated theory -of phlogiston, which held its ground in chemistry up -to the time of Lavoisier. He died about 1734.</p> - -<p>Animism survived him for some time, maintained -by the zeal of a few faithful disciples. But after the<span class="pagenum" id="Page_10">[Pg 10]</span> -witty mockery of Bordeu,<a id="FNanchor_1" href="#Footnote_1" class="fnanchor">[1]</a> -in 1742, it began to decay. -We must, however, point out that an attempt to revive -this theory was made in 1878 by a well-known doctor -of the last generation, E. Chauffard. While preserving -the essential features of the theory, this learned -physician proposed to bring it into harmony with -modern science, and to free it from all the reproaches -which had been levelled at it.</p> - -<p><i>The Animism of E. Chauffard.</i>—These reproaches -were numerous. The most serious is of a philosophic -nature. It rises from the difficulty of conceiving a -direct and immediate action of the soul, considered as -a spiritual principle, upon the matter of the body. -There is such an abyss—hewn by the philosophic -mind itself—between soul and body, that it is impossible -to imagine any relation between them. We -can only get a glimpse of how the soul might become -an instrument of action.</p> - -<p>This was the problem which sorely tried the genius -of Leibniz. Descartes, in earlier days, attacked it -vigorously, like an Alexander cutting the Gordian -knot. He separated the soul from the body, and -made of the latter a pure machine in the government -of which the soul had no part. He attributed all the -known manifestations of vital activity to inanimate -forces. Leibniz, also, was compelled to reject all -action, all contact, all direct relation, every real bond -between soul and body, and to imagine between them -<span class="pagenum" id="Page_11">[Pg 11]</span>a purely metaphysical relation—pre-established harmony:—“Soul -and body agree in virtue of this -harmony, the harmony pre-established since the -creation, and in no way by a mutual, actual, physical -influence. Everything that takes place in the soul -takes place as if there were no body, and so everything -takes place in the body as if there were no -soul.” At this point we almost reach a scientific -materialism. It is easy for the materialist to break -this frail tie of pre-established harmony which so -loosely unites body and soul, and to exhibit the -organism as under the sole control of universal -mechanics and physics.</p> - -<p>Thus the weak point of Stahl’s animism was the -supposition of a direct action exercised on the organism -by a distinct, heterogeneous, spiritual principle.</p> - -<p>Chauffard has endeavoured to avoid this pitfall. In -conformity with modern ideas, he has brought together -what the ancient philosophers and Stahl himself -separated—the activity of matter and the activity of -the soul. “Thought, action, function, are embraced -in an indissoluble union.” This is the classical but -not very lucid theory which has been so often reproduced—<i>Homo -factus est anima vivens</i>—which -Bossuet has expressed in the celebrated formula: -“Soul and body form a natural whole.”</p> - -<p>A second objection raised against animism is that -the soul acts consciously, with reflection, and with -volition, and that its essential attributes are not found -in most physiological phenomena, which, on the contrary -are automatic, involuntary, and unconscious. -The contradictory nature of these characteristics has -obliged vitalists to conceive of a vital principle -distinct from thought. Chauffard, agreeing here with<span class="pagenum" id="Page_12">[Pg 12]</span> -Boullieu, Tissot, and Stahl himself, does not accept -this distinction; he refuses to shatter the unity of the -vivifying and thinking principle. He prefers to attribute -to the soul two modes of action: the one -which is exercised on the acts of thought, and hence -it proceeds consciously, with reflection, and with -volition; the other exercising control over the physiological -phenomena which it governs, “by unconscious -impressions, and by instinctive determinations, obeying -primordial laws.” This soul is hardly in keeping with -his definition of a conscious, reflecting, and voluntary -principle; it is a new soul, a somatic soul, singularly -akin to that <i>rachidian soul</i> which, according to -Pflüger, a well-known German physiologist, resides -in each segment of the spinal marrow, and is responsible -for reflex movements.</p> - -<p><i>Twofold Modality of the Soul.</i>—This twofold -modality of the soul, this duality admitted by Stahl -and his disciples, was repugnant to many thinkers, -and it is this repugnance that gave rise to the vitalistic -school. It appeared to them to be a heresy tainted -by materialism—and so it was. In this lay the -strength and the weakness of animism. It admits -of a unique animating principle for all the manifestations -of the living being, for the higher facts in the -realm of thought, and for the lower facts connected -with the body. It throws down the barriers which -separate them. It fills up the gap between the -different forms of human activity, and assimilates -them the one to the other.</p> - -<p>Now this is precisely what materialism does. It, -too, reduces to a single order the psychical and physiological -phenomena, between which it no longer -recognizes anything but a difference of degree,<span class="pagenum" id="Page_13">[Pg 13]</span> -thought being only a maximum of the vital movement, -or life a minimum of thought. In truth, the -aims of the two schools are diametrically opposed; -the one claims to raise corporeal activity to the -dignity of thinking activity, and to spiritualize the -vital fact; the other lowers the former to the level of -the latter and materializes the psychic fact. But, -though the intentions are different, the result is -identical. Spiritualistic monism inclines towards -materialistic monism. One step more, and the soul, -confused with life, will be confused with physical -forces.</p> - -<p>On the other hand, twofold modality has this -advantage, that it escapes the objection drawn from -the existence of so many living beings to which a -thinking soul cannot be attributed; an anencephalous -fœtus, the young of the higher animals, the lower -animals and plants, living without thought, or with a -minimum of real, conscious thought. The advocate -of animism replies that this physiological activity is -still a soul, but one which is barely aware of its -existence—a gleam of consciousness. In this theory, -the knowledge of self, the consciousness, is of all -degrees. On the other hand, in the eyes of the -vitalist, it is an absolute fact which allows of no -attenuation, of no middle course between the being -and the non-being.</p> - -<p>It is this conception of the continuity of the soul and -life, it is the affirmation of a possible lowering of the -complete consciousness down to a mere gleam of knowledge, -and finally down to unconscious vital activity, -which saved animism from complete shipwreck. That -is why this ancient doctrine finds, even in the present -day, a few rare supporters. An able German scientist,<span class="pagenum" id="Page_14">[Pg 14]</span> -G. von Bunge, well known for his researches in physiological -chemistry, professes animistic views in a work -which appeared in 1889. He attributes to organized -beings a guiding principle, a kind of vital soul. A -distinguished naturalist, Rindfleisch, of Lübeck, has -likewise taken his place among the advocates of what -we may call neo-animism.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_15">[Pg 15]</span></p> - -<h3 class="nobreak" id="CHAPTER_III">CHAPTER III.<br /> - - -<small>VITALISM.</small></h3> -</div> - - -<p class="prel">Its Extreme Forms—Early Vitalism, and Modern Neo-vitalism—Advantage -of distinguishing between Soul and Life—§ -1. <i>The Vitalism of Barthez</i>—Its Extension—The Seat of -the Vital Principle—The Vital Knot—The Vital Tripod—Decentralisation -of the Vital Principle—§ 2. <i>The Doctrine -of Vital Properties</i>—Galen, Van Helmont, Xavier Bichat, -and Cuvier—Vital and Physical Properties antagonistic—§ -3. <i>Scientific Neo-vitalism</i>—Heidenhain—§ 4. <i>Philosophical -Neo-vitalism</i>—Reinke.</p> - - - -<p><i>Extreme Forms: Early Vitalism and Modern Neo-vitalism.</i>—Contemporary -neo-vitalism has weakened -primitive vitalism in some important points. The -latter made of the vital fact something quite specific, -irreducible either to the phenomena of general physics -or to those of thought. It absolutely isolated life, -separating it above from the soul, and below from inanimate -matter. This sequestration is nowadays -much less rigorous. On the psychical side the barrier -remains, but it is lowered on the material side. The -neo-vitalists of to-day recognize that the laws of -physics and chemistry are observed within, as well as -without, the living body; the same natural forces -intervene in both, only they are “otherwise directed.”</p> - -<p>The vital principle of early times was a kind of -anthromorphic, pagan divinity. To Aristotle, this -force, the <i>anima</i>, <i>the Psyche</i>, worked, so to speak, with<span class="pagenum" id="Page_16">[Pg 16]</span> -human hands. According to the well-known expression, -its situation in the human body corresponds -to that of a pilot on a vessel, or to that of a sculptor -or his assistant before the marble or clay. And, in -fact, we have no other clear image of a cause external -to the object. We have no other representation of a -force external to matter than that which is offered by -the craftsman making an object, or in general by the -human being with his activity, free, or supposed to be -free, and directed towards an end to be realized.</p> - -<p>Personifications of this kind, the mythological -entities, the imaginary beings, the ontological fictions, -which ever filled the stage in the mind of our predecessors, -have definitely disappeared; no longer have -they a place in the scientific explanations of our time. -The neo-vitalists replace them by <i>the idea of direction</i>, -which is another form of the same idea of finality. -The series of second causes in the living being seems -to be regulated in conformity with a plan, and directed -with a view to carrying it out. The tendency which -exists in every being to carry out this plan,—that is to -say, the tendency towards its end,—gives the impulse -that is necessary to carry it out. Neo-vitalists claim -that vital force directs the phenomena which it does not -produce, and which are in reality carried out by the -general forces of physics and chemistry.</p> - -<p>Thus, the directing impulse, <i>considered as really -active</i>, is the last concession of modern vitalism. If -we go further, and if we refuse to the directing idea -executive power and efficient activity, the vital -principle is weakened, and we abandon the doctrine. -We can no longer invoke it. We cease to be vitalists -if the part played by the vital principle is thus far -restricted. At first it was both the author of the<span class="pagenum" id="Page_17">[Pg 17]</span> -plan and the universal architect of the organic edifice; -it is now only the architect directing his workmen, -and they are physical and chemical agents. It is now -reduced to the plan of the work, and even this plan -has no objective existence; it is now only an <i>idea</i>. -It has only a shadow of reality. To this it has been -reduced by certain biologists. For this we may thank -Claude Bernard; and he has thereby placed himself -outside and beyond the weakest form of vitalism. He -did not consider the <i>idea of direction</i> as a real -principle. The connection of phenomena, their -harmony, their conformity to a plan grasped by the -intellect, their fitness for a purpose known to the -intellect, are to him but a mental necessity, a metaphysical -concept. The plan which is carried out has -only a subjective existence; the directing force has no -efficient virtue, no executive power; it does not -emerge from the intellectual domain in which it took -its rise, and does not “react on the phenomena which -enabled the mind to create it.”</p> - -<p>It is between these two extreme incarnations of the -vital principle, on the one hand an executive agent, on -the other a simple directing plan, that the motley procession -of vitalist doctrines passes on its way. At the -point of departure we have a vital force, personified, -acting, as we have stated, as if with human hands -fashioning obedient matter; this is the pure and -primitive form of the theory. At the other extreme we -have a vital force which is now only a directing idea, -without objective existence, and without an executive -rôle; a mere concept by which the mind gathers -together and conceives of a succession of physico-chemical -phenomena. On this side we are brought -into touch with monism.</p> - -<p><span class="pagenum" id="Page_18">[Pg 18]</span></p> - -<p><i>The Reasons given by the Vitalists for distinguishing -Soul from Life.</i>—It is, in particular, on the opposite -side, in the psychical world, that the early vitalists professed -to entrench themselves. We have just seen that -their doctrines were not so subtle as those of to-day; -the vital principle to them was a real agent, and not an -ideal plan in the process of being carried out. But -they distinguished this spiritual principle from another -co-existent with it in superior living beings—at any -rate, in man: the thinking soul. They boldly distinguished -between them, because the activity of the -one is manifested by knowledge and volition, while -on the contrary, the manifestations of the other for -the most part escape both consciousness and volition.</p> - -<p>In fact, we know nothing of what goes on in the -normal state of our organs. Their perfect performance -of their functions is translated to us solely by an -obscure feeling of comfort. We do not feel the beating -of the heart, the periodic dilations of the arteries, -the movements of the lungs or intestine, the glands at -their work of secretion, or the thousand reflex manifestations -of our nervous system. The soul, which is -conscious of itself, is nevertheless ignorant of all this -vital movement, and is therefore external to it.</p> - -<p>This is the view of all the philosophers of antiquity. -Pythagoras distinguished the real soul, the thinking -soul, the <i>Nous</i>, the intelligent and immortal principle, -characterized by the attributes of consciousness and -volition, from the vital principle, the <i>Psyche</i>, which -gives breath and animation to the body, and which is -a soul of secondary majesty, active, transient, and -mortal. Aristotle did the same. On the one side he -placed the soul properly so called, the <i>Nous</i> or -intellect—that is to say, the understanding with its<span class="pagenum" id="Page_19">[Pg 19]</span> -rational intelligence; on the other side was the -directing principle of life, the irrational and vegetative -Psyche.</p> - -<p>This distinction agrees with the fact of the diffusion -of life. Life does not belong to the superior animals -alone, and to the man in whom we can recognize a -reasoning soul. It is extended to the vast multitude -of humbler beings to which such lofty faculties cannot -be attributed, the invertebrates, microscopic animals, -and plants. The advantage is compensated for by -the inconvenience of breaking down all continuity -between the soul and life; a continuity which is the -principle of the two other doctrines, animism and -monism, and which is, we may say, the very aim and -the unquestionable tendency of science.</p> - -<p>As for classical philosophy, it satisfies the necessity -of establishing the unity of the living being,—<i>i.e.</i>, of -bringing into harmony soul and body,—but in a -manner which we need not here discuss. It attributes -to the soul several modalities, several distinct -powers: powers of the vegetative life, powers of the -sensitive life, and powers of the intellectual life. And -this other solution of the problem would be, in the -opinion of M. Gardair, in complete agreement with -the doctrines of St. Thomas Aquinas.</p> - - -<h4>§ 1. <span class="smcap">The Vitalism of Barthez: its Extension.</span></h4> - -<p>Vitalism reached its most perfect expression in the -second half of the eighteenth century in the hands of -the representatives of the Montpellier school—Bordeu, -Grimaud, and Barthez. The last, in particular, -contributed to the prevalence of the doctrine in<span class="pagenum" id="Page_20">[Pg 20]</span> -medical circles. A man of profound erudition, a -collaborates with d’Alembert in the <i>Encyclopædia</i>, -he exercised quite a preponderant influence on the -medicine of his day. Stationed at Paris during part -of his career, physician to the King and the Duke of -Orleans, we may say that he supported his theories by -every imaginable influence which might contribute to -their success. In consequence of this, the medical -schools taught that vital phenomena are the immediate -effects of a force which has no analogues outside the -living body. This conception reigned unchallenged -up to the days of Bichat.</p> - -<p>After Bichat, the vitalism of Barthez, more or less -modified by the ideas of the celebrated anatomist, -continued to hold its own in all the schools of -Europe until about the middle of the nineteenth -century. Johannes Müller, the founder of physiology -in Germany, admitted, about 1833, the existence of a -unique vital force “aware of all the secrets of the -forces of physics and chemistry, but continually in -conflict with them, as the supreme cause and regulator -of all phenomena.” When death came, this principle -disappeared and left no trace behind. One of the -founders of biological chemistry, Justus Liebig, who -died in 1873, shared these ideas. The celebrated -botanist, Candolle, who lived up to 1893, taught at -the beginning of his career that the vital force was one -of the four forces ruling in nature, the other three -being—attraction, affinity, and intellectual force. -Flourens, in France, made the vital principle one of -the five properties of forces residing in the nervous -system. Another contemporary, Dressel, in 1883, -endeavoured to bring back into fashion this rather -primitive, monistic, and efficient vitalism.</p> - -<p><span class="pagenum" id="Page_21">[Pg 21]</span></p> - -<p><i>The Seat of the Vital Principle.</i>—Meanwhile, -another question was asked with reference to this -vital principle. It was a question of ascertaining its -seat: or, in other words, of finding its place in the -organism. Is it spread throughout the organism, or is -it situated in some particular spot from which it acts -upon every part of the body? Van Helmont, a celebrated -scientist at the end of the sixteenth century, -who was both physician and alchemist, gave the first -and rather quaint solution of this difficulty. The vital -principle, according to him, was situated in the -stomach, or rather in the opening of the pylorus. It -was the <i>concierge</i>, so to speak, of the stomach. The -Hebrew idea was more reasonable. The life was -connected with the blood, and was circulated with it -by means of all the veins of the organism. It escaped -from a wound at the same time as the liquid blood. -It is clear that in this belief we see why the Jews were -forbidden to eat meat which had not been bled.</p> - -<p><i>The Vital Knot.</i>—In 1748 a doctor named Lorry -found that a very small wound in a certain region of -the spinal marrow brought on sudden death. The -position of this remarkable point was ascertained in -1812 by Legallois, and more accurately still by -Flourens in 1827. It is situated in the rachidian -bulb, at the level of the junction of the neck and the -head; or more precisely, on the floor of the fourth -ventricle, near the origin of the eighth pair of cranial -nerves. This is what was called the <i>vital knot</i>. -Upon the integrity of this spot, which is no bigger -than the head of a pin, depends the life of the animal. -Those who believed in a localisation of the vital -principle thought that they had found the seat -desired; but for that to be so the destruction of this<span class="pagenum" id="Page_22">[Pg 22]</span> -spot must be irremediable, and must necessarily cause -death. But if the <i>vital knot</i> be destroyed, and -respiration be artificially induced by means of a -bellows, the animal resists: it continues to live. It is -only the nervous stimulating mechanism of the -respiratory movements which has been attacked in -one of its essential parts.</p> - -<p>Life, therefore, resides no more in this point than it -does in the blood or in the stomach. Later experiment -has shown that it resides everywhere, that each -organ enjoys an independent life. Each part of the -body is, to use Bordeu’s strong expression, “<i>an animal -in an animal</i>”; or to adopt the phrase due to Bichat, -“<i>a particular machine within the general machine</i>.”</p> - -<p><i>The Vital Tripod.</i>—What then is life, or, in other -words, what is the biological activity of the individual, -of the animal, of man? It is clearly the sum total, or -rather, the harmony of these partial lives of the -different organs. But in this harmony it seems that -there are certain instruments which dominate and -sustain the others. There are some whose integrity -is more necessary to the preservation of existence and -health, and of which any lesion makes death more -inevitable. They are the lungs, the heart, and the -brain. Death always ensues, said the early doctors, if -any one of these three organs be injured. Life -depends, therefore, on them, as if upon a three-legged -support. Hence the idea of the <i>vital tripod</i>. It is no -longer a single seat for the vital principle, but a kind -of throne on three-supports. Life is decentralized.</p> - -<p>This was only the first step, very soon followed by -many others, in the direction of vital decentralization. -Experiment showed, in fact, that every organ separated -from the body will continue to live if provided with<span class="pagenum" id="Page_23">[Pg 23]</span> -the proper conditions. And here, it is not only a -question of inferior beings; of plants that are propagated -by slips; of the <i>hydra</i> which Trembley cut -into pieces, each of which generated a complete hydra; -of the <i>naïs</i> which C. Bonnet cut up into sections, each -of which reconstituted a complete annelid. There is -no exception to the rule.</p> - -<p><i>Decentralization of the Vital Principle.</i>—The result -is the same in the higher vertebrates, only the experiment -is much more difficult. At the Physiological -Congress of Turin in 1901, Locke showed the heart of -a hare, extracted from the body of the animal, and -beating for hours as energetically and as regularly as -if it were in its place. He suspended it in the air of -a room at the normal temperature, the sole condition -being that it was irrigated with a liquid composed of -certain constituents. The animal had been dead some -time. More recently Kuliabko has shown in the same -way the heart of a man still beating, although the -man had been dead some eighteen hours. The same -experiment is repeated in any physiological laboratory, -in a much easier manner, with the heart of a -tortoise. This organ, extracted from the body, fitted -up with rubber tubes to represent its arteries and -veins, and filled with the defibrinated blood of a horse -or an ox taken from the slaughter-house, works for -hours and days pumping the liquid blood into its -rubber aorta, just as if it were pumping it into the -living aorta.</p> - -<p>But it is unnecessary to multiply examples. Every -organ can be made to live for a longer or shorter -period even though removed from its natural position; -muscles, nerves, glands, and even the brain itself. -Each organ, each tissue therefore enjoys an inde<span class="pagenum" id="Page_24">[Pg 24]</span>pendent -existence; it lives and works for itself. -No doubt it shares in the activity of the whole, but -it may be separated therefrom without being thereby -placed in the category of dead substances. For each -aliquot part of the organism there is a partial life and -a partial death.</p> - -<p>This decentralization of the vital activity is finally -extended in complex beings from the organs to the -tissues, and from the tissues to the anatomical -elements—the cells. The idea of decentralization -has given birth to the second form of vitalism, a -softened down and weakened form—namely, pluri-vitalism, -or the theory of vital properties.</p> - - -<h4>§ 2. <span class="smcap">The Theory of Vital Properties.</span></h4> - -<p>The advocates of the theory of vital properties have -cut up into fragments the monistic and indivisible -guiding principle of Bordeu and Barthez. They have -given it new currency—pluri-vitalism. This theory -maintains the existence of spiritual powers of a lower -order, which control phenomena more intimately than -the vital principle did. These powers, less lofty in -their dignity than the rational soul of the animists, or -the soul of secondary majesty of the unitarian -vitalists, are eventually incorporated in the living -matter of which they will then be no longer more -than the properties. Brought into closer connection -therefore with the sensible world, they will be more -in harmony with the spirit of research and with -scientific progress.</p> - -<p>The defect of the earlier conceptions, their common -illusion, rose from their seeking the cause outside the<span class="pagenum" id="Page_25">[Pg 25]</span> -object, from their demanding an explanation of vital -phenomena from a principle external to living, -immaterial, and unsubstantial matter. Here this -defect is less marked. The pluri-vitalists will in turn -appeal to the vital properties as modes of activity, -inherent in the living substance in which and by which -they are manifested, and derived from the arrangement -of the molecules of this substance—that is to say, from -its organization. This is almost the conception of -the present day.</p> - -<p>But this progress will only be realized at the end of -the evolution of the pluri-vitalist theory. At the outset -this theory seems an exaggeration of its predecessor, -and a still more exaggerated form of the mythological -paganism with which it was reproached. The archeus, -the blas, the properties, the spirits—all have at first -the effect of the genii or of the gods imagined by the -ancients to preside over natural phenomena, of -Neptune stirring up the waters of the sea, and of -Eolus unchaining the winds. These divinities of the -ancient world, the nymphs, the dryads, and the sylvan -gods, seem to be transported to the Middle Ages, to -that age of argument, that philosophical period of the -history of humanity, and there metamorphosed into -occult causes, immaterial powers, and personified -forces.</p> - -<p><i>Galen.</i>—The first of the pluri-vitalists was Galen, -the physician of Marcus Aurelius, the celebrated -author of an Encyclopædia of which the greater part -has been lost, and of which the one book preserved -held its own as the anatomical oracle and breviary -throughout the Middle Ages. According to Galen -the human machine is guided by three kinds of -spirits: <i>animal spirits</i>, presiding over the activity of<span class="pagenum" id="Page_26">[Pg 26]</span> -the nervous system; <i>vital spirits</i> governing most of -the other functions; and finally, <i>natural spirits</i> -regulating the liver and susceptible of incorporation -in the blood. In the sixteenth century, in the time of -Paracelsus, Galen’s spirits became <i>Olympic spirits</i>. -They still presided over the functional activity of the -organs, the liver, heart, and brain, but they also -existed in all the bodies of nature.</p> - -<p><i>Van Helmont.</i>—Finally, the theory was laid down -by Van Helmont, physician, chemist, experimentalist, -and philosopher, endowed with a rare and penetrating -intellect. Here we find many profound truths combined -with fantastic dreams. Refusing to admit the -direct action of an immaterial agent, such as the soul, -on inert matter, on the body, he filled up the abyss -which separated them by creating a whole hierarchy -of immaterial principles which played the part of -mediators and executive agents. At the head of this -hierarchy was placed the thinking and immortal soul; -below was the sensitive and mortal soul, having for its -minister the <i>principal archeus</i>, the <i>aura vitalis</i>, a kind -of incorporeal agent, which is remarkably like the -vital principle, and which had its seat at the orifice of -the stomach. Below again were the subordinate -agents, the <i>blas</i>, or <i>vulcans</i> placed in each organ, and -intelligently directing its mechanism like skillful -workmen.</p> - -<p>These chimerical ideas are not, however, so far -astray as the theory of vital properties. When we -see a muscle contract, we say that this phenomenon -is due to a vital property—<i>i.e.</i>, a property without any -analogue in the physical world, namely <i>contractility</i>, -in the same way the nerve possesses two vital -properties, <i>excitability</i> and <i>conductibility</i>, which Vulpian<span class="pagenum" id="Page_27">[Pg 27]</span> -proposed to blend into one, calling it <i>neurility</i>. These -are mere names, serving as a kind of shorthand; but -to those who believe that there is something real in it, -this something is not very far from the <i>blas</i> of Van -Helmont. <i>Vulcans</i>, hidden in the muscle or the nerve, -are here detected by attraction, there by the production -and the propagation of the nervous influx; -that is to say, by phenomena of which we as yet -know no analogues in the physical world, but of -which we cannot say that they do not exist.</p> - -<p><i>X. Bichat and G. Cuvier: Vital and Physical -Properties Antagonistic.</i>—The archeus and the blas of -Van Helmont were but a first rough outline of -vital properties. Xavier Bichat, the founder of general -anatomy, wearied of all these incorporeal entities, of -these unsubstantial principles with which biology was -encumbered, undertook to get rid of them by the -methods of the physicist and the chemist. The physics -and the chemistry of his day referred phenomenal -manifestations to the properties of matter, gravity, -capillarity, magnetism, etc. Bichat did the same. -He referred vital manifestations to the properties of -living tissues, if not, indeed, of living matter. Of -these properties as yet but very few were known: -the irritability described by Glisson, which is the -excitability of current physiology; and the irritability -of Haller, which is nothing but muscular contractility. -Others had to be discovered.</p> - -<p>There is no need to recall the mistake made by -Bichat and followed by most scientific men of his -time, such as Cuvier in France, and J. Müller in -Germany, for the story has been told by Claude -Bernard. His mistake was in considering the vital -properties not only as distinct from physical properties<span class="pagenum" id="Page_28">[Pg 28]</span> -but even as opposed to them. The one preserve the -body, the others tend to destroy it. They are always -in conflict. Life is the victory of the one; death is -the triumph of the other. Hence the celebrated -definition given by Bichat: “Life is the sum total of -functions which resist death,” or the definition of the -Encyclopædia: “Life is the contrary of death.”</p> - -<p>Cuvier has illustrated this conception by a graphic -picture. He represents a young woman in all the -health and strength of youth suddenly stricken by -death. The sculptural forms collapse and show the -angularities of the bones; the eyes so lately sparkling -become dull; the flesh tint gives place to a livid -pallor; the graceful suppleness of the body is now -rigidity, “and it will not be long before more horrible -changes ensue; the flesh becomes blue, green, black, -one part flows away in putrid poison, and another -part evaporates in infectious emanations. Finally, -nothing is left but saline or earthy mineral principles, -all the rest has vanished.” Now, according to Cuvier, -what has happened?</p> - -<p>These alterations are the effect of external agents, -air, humidity, and heat. They have acted on the -corpse just as they used to act on the living being; -but before death their assault had no effect, because it -was repelled by the vital properties. Now that life -has disappeared the assault is successful. We know -now that external agents are not the cause of these -disorders. They are caused by the microbes of -putrefaction. It is against <i>them</i> that the organs were -struggling, and not against physical forces.</p> - -<p>The mistake made by Bichat and Cuvier was inexcusable, -even in their day. They were wrong not -to attach the importance they deserved to Lavoisier’s<span class="pagenum" id="Page_29">[Pg 29]</span> -researches. He had asserted, apropos of animal heat -and respiration, the identity of the action of physical -agents in the living body and in the external world. -On the other hand, Bichat, by a flash of genius, decentralized -life, dispersing the vital properties in the -tissues, or, as we should now say, in the living matter. -It was from the comparison between the constitution -and the properties of living matter and those of inanimate -matter that light was to come.</p> - - -<h4>§ 3. <span class="smcap">Scientific Neo-Vitalism.</span></h4> - -<p>We can now understand the nature of modern -neo-vitalism. It borrows from its predecessor its -fundamental principle—namely, the specificity of the -<i>vital fact</i>. But this specificity is no longer <i>essential</i>, -it is only <i>formal</i>. The difference between it and the -physical fact grows less and almost vanishes. It consists -of a diversity of mechanisms or executive agents. -For example, digestion transforms the alimentary -starch in the intestines into sugar; the chemist does -the same in his laboratory, only he employs acids, -while the organism employs special agents, ferments, -in this case a diastase. It is a particular form of -chemistry, but still it is a chemistry. That is how -Claude Bernard looked at it. The vital fact was not -fundamentally distinguished from the physico-chemical -fact, but only in form.</p> - -<p>This expurgated and accommodated vitalism -(Claude Bernard pushed his concessions so far as to -call his doctrine “physico-chemical vitalism”) was revived -a few years ago by Chr. Bohr and Heidenhain.</p> - -<p>Other biologists, instead of attributing the difference<span class="pagenum" id="Page_30">[Pg 30]</span> -between the phenomena of the two orders to the -manner of their occurrence, seem to admit the complete -identity of the mechanisms. It is no longer -then in itself, individually, that the vital act is -particularized, but in the manner in which it is -linked to others. The vital order is a series of -physico-chemical acts realizing an ideal plan.</p> - -<p>Neo-vitalism has therefore assumed two forms, -one the more scientific and the other the more -philosophical.</p> - -<p><i>Chr. Bohr and Heidenhain.</i>—Its scientific form was -given to it by Chr. Bohr, an able physiologist at -Copenhagen, and by Heidenhain, a professor at -Breslau, who was one of the lights of contemporary -German physiology. The course of their researches -led these two experimentalists, working independently, -to submit to fresh investigation the ideas of -Lavoisier and those of Bichat, on the relation of -physico-chemical forces to the vital forces.</p> - -<p>It was by no means a question of a general -inquiry, deliberately instituted with the object of discovering -the part played respectively by physical and -physiological factors in the performance of the various -functions. Such an investigation would have taken -several generations to complete. No; the question -had only come up incidentally. Chr. Bohr had studied -with the utmost care the gaseous exchanges which -take place between the air and the blood in the lungs. -The gaseous mixture and the liquid blood are face -to face; they are separated by thin membrane formed -of living cells. Will this membrane behave as an -inert membrane deprived of vitality, and therefore -obeying the physical laws of the diffusion of gases? -Well! no. It does not so behave. The most careful<span class="pagenum" id="Page_31">[Pg 31]</span> -measurements of pressures and of solubilities leave no -doubt in this respect. The living elements of the -pulmonary membrane must therefore intervene in -order to disturb the physical phenomenon. Things -happen as if the exchanged gases were subjected not -to a simple diffusion, a physical fact obeying certain -rules, but to a real secretion, a physiological or vital -phenomenon, obeying laws which are also fixed, but -different from the former.</p> - -<p>On the other hand, Heidenhain was led about the -same time to analogous conclusions with respect -to the liquid exchanges which take place within -the tissues, between the liquids (lymphs) which -bathe the blood-vessels externally and the blood -which those vessels contain. The phenomenon is -very important because it is the prologue of the -actions of nutrition and assimilation. Here again, -the two factors of exchange are brought into relation -through a thin wall, the wall of the blood-vessel. The -physical laws of diffusion, of osmosis, and of dialysis, -enable us to foretell what would take place if the -vitality of the elements of the wall did not intervene. -Heidenhain thought he observed that things took -place otherwise. The passage of the liquids is disturbed -by the fact that the cellular elements are alive. -It assumes the characteristics of a physiological act, -and no longer those of a physical act. Let us add -that the interpretation of these experiments is difficult, -and it has given rise to controversies which still -persist.</p> - -<p>These two examples, around which others might be -grouped, have led certain physiologists to diminish the -importance of the physical factors in the functional -activity of the living being to the advantage of the<span class="pagenum" id="Page_32">[Pg 32]</span> -physiological factors. It would therefore seem that -the vital force, to use a rather questionable form -of language, withdraws in a certain measure the -organized being from the realm of physical forces—and -this conclusion is one form of contemporary -neo-vitalism.</p> - - -<h4>§ 4. <span class="smcap">Philosophical Neo-Vitalism.</span></h4> - -<p>Contemporary neo-vitalism has assumed another -form, more philosophical than scientific, by which it is -brought closer to vitalism, properly so called. We -should like to mention the experiment of Reinke,<a id="FNanchor_2" href="#Footnote_2" class="fnanchor">[2]</a> -in Germany. Reinke is a botanist of distinction, who -distinguishes the speculative from the positive domain -of science, and cultivates both with success.</p> - -<p>His ideas are analogous to those of A. Gautier, of -Chevreul, and of Claude Bernard himself. He thinks, -with these masters, that the mystery of life is not to be -found in the nature of the forces that it brings into -play, but in the direction that it gives them. All these -thinkers are struck by the order and the direction -impressed upon the phenomena which take place -in the living being, by their interconnection, by their -apparent adaptation to an end, by the kind of impression -that they give of a plan which is being -carried out. All these reflections lead Reinke to -attach great weight to the idea of a “directing -force.”</p> - -<p>The physico-chemical energies are no doubt the -only ones which are manifested in the organized -being, but they are directed as a blind man is by his<span class="pagenum" id="Page_33">[Pg 33]</span> -guide. It seems as if a <i>double</i> accompanies them like -a shadow. This intelligent guide of blind, material -force is what Reinke calls a <i>dominant</i>. Nothing -could be more like the blas and the archeus of Van -Helmont. Material energies would thus be paired -off with their blas, their dominants, in the living -organisms. In them there would therefore be two categories -of force: “material forces,” or rather, material -energies obeying the laws of universal energetics; -and in the second place, intelligent “spiritual forces,” -the dominants. When the sculptor is working his -marble, in every blow which elicits a spark there is -something more than the strong force of the hammer. -There is thought, the volition of the artist, which is -realizing a plan. In a machine there is more than -machinery. Behind the wheels is the object which -the author had in view when he adjusted them for a -determined end. The energies spent in action are -regulated by the adjustment—that is to say, by the -dominants due to the intellect of the constructor.</p> - -<p>Thus it is in the living machine. The dominants -in this case are the guardians of the plan, the agents -of the aim in view. Some regulate the functional -activity of the living body, and some regulate its -development and its construction. Such is the second -form, the philosophical form, extreme and teleological, -of contemporary neo-vitalism.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_34">[Pg 34]</span></p> - -<h3 class="nobreak" id="CHAPTER_IV">CHAPTER IV.<br /> - -<small>THE MONISTIC THEORY.</small></h3></div> - - - -<p class="prel">Physico-chemical Theory of Life.—Iatro-mechanism.—Descartes, -Borelli.—Iatro-chemistry.—Sylvius le Boë.—The -Physico-chemical Theory of Life.—Matter and Energy.—Heterogeneity -is merely the result of the arrangement or -combination of homogeneous bodies.—Reservation relative -to the world of thought.—The Kinetic Theory.</p> - - -<p>The unicist or monistic doctrine gives us a third way -of conceiving the functional activity of the living -being, by levelling and blending its three forms of -activity—spiritual, vital, and material. It was -expressed in the seventeenth and eighteenth centuries -in “iatro-mechanism” and “iatro-chemistry,” conceptions -to which have more recently succeeded the -physico-chemical doctrine of life, and finally “current -materialism.”</p> - -<p>Materialism is not only a biological interpretation; -it is a universal interpretation applicable to the whole -of nature, because it is based on a determinate conception -of matter. Here we find ourselves confronted -by the eternal enigma discussed by philosophers -relative to this fundamental problem of force and -matter. We know what answers were given to -the problem by the Ionic philosophers—Thales, -Democritus, Heraclitus, and Anaxagoras, who discarded -the agency of every spiritual power external<span class="pagenum" id="Page_35">[Pg 35]</span> -to matter. The explanation of the world, the -explanation of life, were reduced to the play of -physical or mechanical forces. Epicurus, a little later, -maintained that the knowledge of matter and its -different forms accounts for all phenomena, and therefore -for those of life.</p> - -<p>Descartes, sharply separating the metaphysical -world—that is to say, the soul defined by its attribute, -thought—from the physical or material world -characterized by extension, practically came to the -same conclusions as the materialists of antiquity. To -him, as to them, the living body was a mere machine.</p> - -<p><i>Iatro-mechanism. Descartes. Borelli.</i>—This, then, is -the theory of the iatro-mechanicians, of which we may -consider Descartes the founder, instead of the Greek -philosophers. These ideas held their own for two -centuries, and were productive of such fruitful results -in the hands of Borelli, Pitcairn, Hales, Bernoulli, and -Boerhaave, as to justify the jest of Bacon that “the -philosophy of Epicurus had done less harm to science -than that of Plato.” The iatro-mechanic school tenaciously -held its own until Bichat came upon the scene.</p> - -<p><i>Iatro-chemistry. Sylvius le Boë.</i>—It was from a -reaction against their exaggerations that Stahl -created animism, and the Montpellier school created -vitalism. We gather some idea of the extravagant -character of their explanations by reading Boerhaave. -To this celebrated doctor the muscles were springs, -the heart was a pump, the kidneys a sieve, and the -secretions of the glandular juices were produced by -pressure; the heat of the body was the result of the -friction of the globules of blood against the walls of -the blood-vessels; it was greater in the lungs because -the vessels of the lungs were supposed to be narrower<span class="pagenum" id="Page_36">[Pg 36]</span> -than those of other organs. The inadequacy of these -explanations suggested the idea of completing them -by the aid of the chemistry which was then springing -into being. This chemistry, rudimentary as it was, -longed for a share in the government of living bodies -and in the explanation of their phenomena. Distillations, -fermentations, and effervescences are now -seen to play their rôle, a rôle which was premature -and carried to excess. Iatro-chemistry from the -general point of view is only an aspect of iatro-mechanics; -but it is also an auxiliary. Sylvius le Boë -and Willis were its most eminent representatives. -This theory remained in the background until -chemistry made its great advance—that is to say, in -the days of Lavoisier. After that, its importance has -gradually increased, particularly in the present day. -Nowadays, the general tendency is to regard the -organic functional activity, or even morphogeny—<i>i.e.</i>, -whatever there is that is most peculiar to and characteristic -of living beings—as a consequence of the -chemical composition of their substance. This is a -point of capital importance, and to it we must recur.</p> - -<p><i>The Physico-chemical Theory of Life.</i>—Contemporary -biological schools have made many efforts to secure -themselves from any slips on the philosophical side. -They have avoided in most cases the psychological -problem; they have deliberately refrained from -penetrating into the world of the soul. Hence, <i>the -physico-chemical theory</i> of life has been built up free -from spiritualistic difficulties and objections. But -this prudence did not exclude the tendency. And -there is no doubt, as Armand Gautier said, that “real -science can affirm nothing, but it also can deny -nothing outside observable facts;” and again, that<span class="pagenum" id="Page_37">[Pg 37]</span> -“only a science progressing backwards can venture to -assert that matter alone exists, and that its laws alone -govern the world.” It is none the less true that by -establishing the continuity between inert matter and -living matter, we thereby render probable the continuity -between the world of life and the world of -thought.</p> - -<p><i>Matter and Energy.</i>—Besides, and without any -wish to enter into this burning controversy, it is -only too evident that there is no agreement as to the -terms that are used, and in particular as to “matter” -and “laws of matter.” It is not necessary to repeat -that the geometrical mould in which Descartes cast -his philosophy has long since been broken. The -celebrated philosopher, in defining matter by one -attribute—extension, does not enable us to grasp its -activity, an activity revealed by all natural facts; and -in defining the soul by thought alone, prevents us -from seeking in it the principle of this material activity. -This purely passive matter, consisting of extension -alone, this <i>bare matter</i> was to Leibniz a pure concept. -A philosopher of our own time, M. Magy, has called it -a sensorial illusion. The bodies of nature exhibit to -us <i>matter clad</i> with energy, formed by the indissoluble -union of extension with an inseparable dynamical -principle. The Stoics declared that matter is mobile -and not immobile, active and not inert. Leibniz also -had this in his mind when he associated it indissolubly -with an active principle, an “entelechy.” Others have -said that matter is “an assemblage of forces,” or with -P. Boscovitch, “a system of indivisible points without -extension, centres of force, in fact.” Space would be -the geometrical locus of these points.</p> - -<p>In this conception the materialistic school finds the<span class="pagenum" id="Page_38">[Pg 38]</span> -explanation of all phenomenality. Physical properties, -vital phenomena, psychical facts, all have their foundation -in this immanent activity. Material activity is -a minimum of soul or thought which, by continuous -gradation and progressive complexity, without solution -of continuity, without an abrupt transition from the -homogeneous to the heterogeneous, rises through the -series of living beings to the dignity of the human -soul. The observation of the transitions, an imperfect -tracing of the geometrical method of limits, thus -enables us to pass from material to vital, and from -thence to psychical activity.</p> - -<p><i>Apparent Heterogeneity is the Result of the Arrangement -or the Combination of Homogeneous Bodies.</i>—In -this system, material energy, life, soul would only be -more and more complex combinations of the consubstantial -activity with material atoms. Life appears -distinct from physical force, and thought from life, -because the analysis has not yet advanced far enough. -Thus, glass would appear to the ancient Chaldeans -distinct from the sand and salt of which they made it. -In the same way, again, water, to modern eyes, is -distinct from its constituents, oxygen and hydrogen. -The whole difficulty is that of explaining what this -“arrangement” of the elements can introduce that -is new in the aspect of the compound. We must -know what novelty and apparent homogeneity the -variety of the combinations, which are only special -arrangements of the elementary parts, may produce in -the phenomena. But we do not know, and it is this -ignorance which leads us to consider them as heterogeneous, -irreducible, and distinct in principle. The -vital phenomenon, the complexus of physico-chemical -facts, thus appears to us essentially different from<span class="pagenum" id="Page_39">[Pg 39]</span> -those facts, and that is why we picture to ourselves -“dominants” and “directing forces” more or less -analogous to the sidereal guiding principle of Kepler, -which, before the discovery of universal attraction, -regulated the harmony of the movements of the -planets.</p> - -<p><i>A Reservation relative to the Psychical Order.</i>—The -scientific mind has shown in every age a real -predilection towards the mechanical or materialistic -theory. Contemporary scientists as a whole have -accepted it in so far as it blends the vital and the -physical orders. Objections and contradictions are -only offered in the realm of psychology. A. Gautier, -for example, has contested with infinite originality -and vigour the claims of the materialists who would -reduce the phenomenon of thought to a material -phenomenon. The most general characteristic of -material phenomenality is—as we shall later see—that -it may be considered as a mutation of energy—<i>i.e.</i>, -it obeys the laws of energetics. Now thought, -says A. Gautier, is not a form of material energy. -Thought, comparison, volition, are not acts of material -phenomenality; they are states. They are realities; -they have no mass; they have no physical existence. -They respond to adjustments, arrangements, and -concerted groupings of material manifestations of -chemical molecules. They escape the laws of -energetics.</p> - -<p><i>Kinetic Theory.</i>—We shall lay aside for a moment -this serious problem relative to the limits of the world -of conscious thought and of the world of life. It is on -the other side, on the frontiers of living and inanimate -nature, that the mechanical view triumphs. It -has furnished a universal conception agreeing with<span class="pagenum" id="Page_40">[Pg 40]</span> -phenomena of every kind—viz., the kinetic theory, -which ascribes everything in nature to the movements -of particles, molecules, or atoms.</p> - -<p>The living and the physical orders are here reduced -to one unique order, because all the phenomena of the -sensible universe are themselves reduced to one and -the same mechanics, and are represented by means of -the atom and of motion. This conception of the -world, which was that of the philosophers of the Ionic -school in the remotest antiquity, which was modified -later by Descartes and Leibniz, has passed into -modern science under the name of the kinetic theory. -The mechanics of atoms ponderable or imponderable, -would contain the explanation of all phenomenality. -If it were a question of physical properties or vital -manifestations, the objective world in final analysis -would offer us nothing but motion. Every phenomenon -would be expressed by an atomistic integral, -and that is the inner reason of the majestic unity -which reigns in modern physics. The forces which -are brought into play by Life are no longer to -be distinguished in this ultimate analysis from -other natural forces. All are blended in molecular -mechanics.</p> - -<p>The philosophical value of this theory is undeniable. -It has exercised on physical science an influence which -is justified by the discoveries which it has suggested. -But to biology, on the other hand, it has lent no aid. -It is precisely because it descends too deeply into -things, and analyzes them to the uttermost, that it -ceases to throw any light upon them. The distance -between the hypothetical atom and the apparent and -concrete fact is too great for the one to be able to -throw light on the other. The vital phenomenon<span class="pagenum" id="Page_41">[Pg 41]</span> -vanishes with its individual aspect; its features can -no longer be distinguished.</p> - -<p>Besides, a whole school of contemporary physicists -(Ostwald of Leipzig, Mach of Vienna) is beginning to -cast some doubt on the utility of the kinetic hypothesis -in the future of physics itself, and is inclined to propose -to substitute for it the theory of energetics. We -shall see, in every case, that this other conception, as -universal as the kinetic theory, <i>the theory of Energy</i>, -causes a vivid light to penetrate into the depths of the -most difficult problems in physiology.</p> - -<p>Such are, with their successive transformations, the -three principal theories, the three great currents -between which biology has been tossed to and fro. -They are sufficiently indicative of the state of positive -science in each age, but one is astonished that they -are not more so; and this is due to the fact that these -conceptions are too general. They soar too high above -reality. More characteristic in this respect will be -particular theories of the principal manifestations of -living matter, of its perpetuity by generation, of the -development by which it acquires its individual form, -on heredity. It is here that it is of importance to -grasp the progressive march of science—that is to say, -the design and the plan of the building which is being -erected, “blindly, so to speak,” by the efforts of an -army of workers, an army becoming more numerous -day by day.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_42">[Pg 42]</span></p> - -<h3 class="nobreak" id="CHAPTER_V">CHAPTER V.<br /> - -<small>THE EMANCIPATION OF SCIENTIFIC RESEARCH -FROM THE YOKE OF PHILOSOPHICAL THEORIES.</small></h3></div> - - -<p class="prel">The excessive use of Hypothetical Agents in Physiological -Explanations—§ 1. <i>Vital Phenomena in Fully-constituted -Organisms</i>—Provisory Exclusion of the Morphogenic -idea—The Realm of the Morphogenic Idea as the -Sanctuary of Vital Force—§ 2. <i>The Physiological Domain -properly so called</i>—Harmony and Connection of Phenomena—Directive -Forces—Claude Bernard’s Work—Exclusion -of Vital Force, of Final Cause, of the “Caprice” -of Living Nature—Determinism—The Comparative -Method—Generality of Vital Phenomena—Views of -Pasteur.</p> - - - -<p>The theories whose history we have just sketched -in broad outline long dominated science and exercised -their influence on its progress.</p> - -<p>This domination has ceased to exist. Physiology -has emancipated itself from their sway, and this, -perhaps, is the most important revolution in the whole -history of biology. Animism, vitalism, materialism, -have ceased to exercise their tyranny on scientific -research. These conceptions have passed from the -laboratory to the study; from being physiological, -they have become philosophical.</p> - -<p>This result is the work of the physiologists of sixty -years ago. It is also the consequence of the general -march of science and of the progress of the scientific -spirit, which shows a more and more marked tendency<span class="pagenum" id="Page_43">[Pg 43]</span> -to separate completely the domain of facts from the -domain of hypotheses.</p> - -<p><i>Excessive Use of Hypothetical Agents in Physiological -Explanations.</i>—It may be said that in the -early part of the nineteenth century, in spite of the -efforts of a few real experimenters from Harvey to -Spallanzani, Hales, Laplace, Lavoisier, and Magendie, -the science of the phenomena of life had not followed -the progress of the other natural sciences. It remained -in the fog of scholasticism. Hypotheses were mingled -with facts, and imaginary agents carried out real acts, -in inexpressible confusion. The soul (<i>animism</i>), the -vital force (<i>vitalism</i>), and the final cause (<i>finalism</i>, -<i>teleology</i>) served to explain everything.</p> - -<p>In truth, it was also at this time that physical -agents, electric and magnetic fluids, or, again, chemical -affinity, played an analogous part in the science of -inanimate nature. But there was at least this -difference in favour of physicists and chemists, that -when they had attributed some new property or -aptitude to their hypothetical agents they respected -what they attributed. The physiological physicians -respected no law, they were subject to no restraint. -Their vital force was capricious; its spontaneity made -anticipation impossible; it acted arbitrarily in the -healthy body; it acted more arbitrarily still in the -diseased body. All the subtlety of medical genius -was called into play to divine the fantastic behaviour -of the spirit of disease. If we speak here of physiologists -and doctors alone and do not quote biologists, -it is because the latter had not yet made their -appearance as authorities; their science had remained -purely descriptive, and they had not yet begun to -explain phenomena.</p> - -<p><span class="pagenum" id="Page_44">[Pg 44]</span></p> - -<p>Such was the state of things during the first years -of the nineteenth century. It lasted, thanks to the -founders of contemporary physiology—Claude Bernard -in France, and Brücke, Dubois-Reymond, Helmholtz, -and Ludwig in Germany—until a separation took -place between biological research and philosophical -theories. This delimitation operated in physiology -properly so called—<i>i.e.</i> in a branch of the biological -domain in which as yet joint tenancy had been the -rule. An important revolution fixed the respective -divisions of experimental science and philosophical -interpretation. It was understood that the one ends -where the other begins, that the one follows the other, -that one may not cross the other’s path. There is -between them only one doubtful region about which -there is dispute, and this uncertain frontier is constantly -being shifted and science daily gains what -philosophy loses.</p> - - -<h4>§ 1. <span class="smcap">Vital Phenomena in Constituted -Organisms.</span></h4> - -<p>A displacement of this kind had taken place at the -time of which we speak. It was agreed, that as far as -concerns the phenomena which take place in <i>a constructed -and constituted living organism</i>, it would no -longer be permissible to allow to intervene in their -explanation forces or energies other than those -which are brought into play in inanimate nature. -Just as when explaining the working of a clock, -the physicist will not invoke the volition or the art -of the maker, or the design that he had in view, but -only the connection of causes and effects which he -has utilized; so, for the living machine, whether the<span class="pagenum" id="Page_45">[Pg 45]</span> -most complex, such as the human body, or the most -elementary, such as the cell, we may not invoke a -final cause, a vital force, external to that organism -and acting on it from without, but only the connections -and the fluctuations of effects which are the -sole actual and efficient causes. In other words -Ludwig, and Claude Bernard in particular, expelled -from the domain of active phenomenality the three -chimeras—Vital Force, Final Cause, and the “Caprice” -of Living Nature.</p> - -<p>But the living being is not only a <i>completely constructed -and completely constituted</i> organism. It is not -a finished clock. It is a clock which is making itself, -a mechanism which is constructing and perpetuating -itself. Nothing of the kind is known to us in inanimate -nature. Physiology has found—in what is -called morphogeny—its temporary limit. It is beyond -this limit, it is in the study of phenomena by which -the organism is constructed and perpetuated, it is in -the region of the functions of generation and development, -that philosophical doctrines expand and flourish. -This is the present frontier of these two powers, -philosophy and science. We shall presently delimit -them more precisely. W. Kühne, a well-known -scientist whose death is deplored, not in Germany -alone, amused himself by studying the division of -biological doctrines among the members of learned -societies and in the world of academies. He -summed up this kind of statistical inquiry by -saying in 1898 at the Cambridge Congress, that -physiologists were nearly all advocates of the physico-chemical -doctrine of life, and that the majority of -naturalists were advocates of vital force, and of the -theory of final causes.</p> - -<p><span class="pagenum" id="Page_46">[Pg 46]</span></p> - -<p><i>Domain of the Morphogenic Idea as the Last Sanctuary -of Vital Force.</i>—We see the reason for this. -Physiology, in fact, has taken up its position in -the explanation of the functional activity of the -constituted organism—<i>i.e.</i>, on a ground where -intervene, as we shall show further on, no energies -and no matter other than universal energies and -matter. Naturalists, on the other hand, have more -especially considered—and from the descriptive point -of view alone, at least up to the times of Lamarck -and Darwin—the functions, the generation, the -development and the evolution of species. Now -these functions are most refractory and inaccessible -to physico-chemical explanations. So, when the -time came to give an account of what they had done, -the zoologists had substituted for executive agents -nothing but vital force under its different names. -To Aristotle it is the vital force itself which, as soon -as it is introduced into the body of the child, moulds -its flesh and fashions it in the human form. Contemporary -naturalists, the Americans C. O. Whitman -and C. Philpotts, for example, take the same line of -argument. Others, such as Blumenbach and Needham, -in the eighteenth century, invoked the same division -under another name, that of the <i>nisus formativus</i>. -Finally, others play with words; they talk of heredity, -of adaptation, of atavism, as if these were real, active, -and efficient beings; while they are only appellations, -names applied to collections of facts.</p> - -<p>This region was therefore eminently favourable -to the rapid increase of hypotheses, and so they -abounded. There were the theories of Buffon, of -Lamarck, of Darwin, of Herbert Spencer, of E. -Haeckel, of His, of Weismann, of De Vries, and<span class="pagenum" id="Page_47">[Pg 47]</span> -of W. Roux. Each biologist of any mark had his own, -and the list is endless. But here already this domain -of theoretical speculation is checked on various sides -by experiment. J. Loeb, a pure physiologist, has -recently given his researches a direction in which -zoology believes may be found the explanation of the -mysterious part played by the male element in -fecundation. On the other hand, the first experiment -of the artificial division of the living cell -(<i>merotomy</i>), with its light upon the part played by -the nucleus in the preservation and regeneration of -the living form, is also the work of a physiological -experimenter. It dates back to 1852, and is due to -Augustus Waller. This experiment was made on the -sensitive nervous cell of the spinal ganglions and on -the motor cell of the anterior cornua of the spinal -cord. The effects were correctly interpreted twelve -or fifteen years later. All that zoologists have done -is to repeat, perhaps unconsciously, this celebrated -experiment and to confirm the result.</p> - -<p>Thus we see that the attack upon the vitalist -sanctuary has commenced. But it would be a grave -mistake to suppose that final cause and vital force are -on the point of being dislodged from their entrenchments. -Philosophical speculation has an ample field -before it. Its frontiers may recede. For a long time -yet there will be room for a more or less modernized -vitalism.</p> - - -<h4>§ 2. <span class="smcap">The Physiological Domain properly so -called.</span></h4> - -<p>Vitalism is even found installed in the region of -physiology, although for the moment this science -limits its ambition to the consideration of the com<span class="pagenum" id="Page_48">[Pg 48]</span>pletely -constructed organized being, perfected in its -form. The explanation of the working of this constituted -machine cannot be complete until we take -into account the harmony and the adjustment of its -parts.</p> - -<p><i>Harmony and Connection of Parts: Directive Forces.</i>—These -constituent parts are the cells. We know -that the progress of anatomy has resulted in the -cellular doctrine—<i>i.e.</i>, in the two-fold affirmation -that the most complicated organism is composed of -microscopic elements, the cells, all similar, true -stones of the living building, and that it derives its -origin from a single cell, egg, or spore, the sexual cell, -or cell of germination. The phenomena of life, looked -at from the point of view of the formed individual, -are therefore harmonized in space; just as, regarded -from the point of view of the individual in formation -and in the species, they are connected in time. This -harmony and this connection are in the eyes of the -majority of men of science the most characteristic properties -of the living being. This is the domain of <i>vital -specificity</i>, of the <i>directive forces</i> of Claude Bernard and -A. Gautier, and of the <i>dominants</i> of Reinke. It is not -certain, however, that this order of facts is more -specific than the other. Generation and development -have been considered by many physiologists, and -quite recently by Le Dantec, as simple aspects or -modalities of nutrition or assimilation, the common -and fundamental property of every living cell.</p> - -<p><i>The Work of Claude Bernard. Exclusion of Vital -Force, of Vital Cause, of the “Caprice” of Living Nature.</i>—It -is not, however, a slight advance or inconsiderable -advantage to have eliminated vitalistic hypotheses -from almost the whole domain of present-day physi<span class="pagenum" id="Page_49">[Pg 49]</span>ology, -and to have them, as it were, thrown back into -its hinterland. This is the work of the scientific men -of the first half of the nineteenth century, and particularly -of Claude Bernard, who has thereby won -the name of the founder or lawgiver of physiology. -They found in the old medical school an obstinate -adversary glorying in its sterile traditions. In vain -was it proved that vital force cannot be an efficient -cause; that it was a creation of the brain, an insubstantial -phantom introduced into the anatomical -marionette and moving it by strings at the will of -any one—its adepts having only to confer upon it a -new kind of activity to account for the new act. All -that had been shown with the utmost clearness by -Bonnet of Geneva, and by many others. It had also -been said that the teleological explanation is equally -futile, since it assigns to the present, which exists, an -inaccessible, and evidently ultimately inadequate cause, -which does not yet exist. These objections were in -vain.</p> - -<p><i>Determinism.</i>—And so it was not by theoretical -arguments that the celebrated physiologist dealt with -his adversaries, but by a kind of lesson on things. In -fact he was continually showing by examples that -vitalism and the theory of final causes were idle errors -which led astray experimental investigation; that -they had prevented the progress of research and the -discovery of the truth in every case and on every -point in which they had been invoked. He laid down -the principle of <i>biological determinism</i>, which is nothing -but the negation of the “caprice” of living nature. -This postulate, so evident that there was no need to -enunciate it in the physical sciences, had to be shouted -from the housetops for the benefit of supporters of<span class="pagenum" id="Page_50">[Pg 50]</span> -vital spontaneity. It is the statement that, under -determined circumstances materially identical, the -same vital phenomena will be identically reproduced.</p> - -<p><i>Comparative Method.</i>—Claude Bernard completed -this critical work by laying down the laws of experiment -on living beings. He commended as the rational -method of research the <i>comparative method</i>. This -should be, and is in fact, the daily instrument of all -those who work in physiology. It compels the -investigator in every research bearing on organized -beings to institute a series of tests, such that the -conditions which are unknown and impossible to -know may be regarded as identical from one test to -another; and when we are certain that a single -condition is variable, it compels him to discover the -character of the condition we are dealing with, and -to learn to appreciate, and to measure its influence. -It is safe to say that the errors which are daily -committed in biological work have their cause in -some infraction of this golden rule. In physical -science the obligation to follow the comparative -method is much less felt. In most cases the <i>witness -test</i><a id="FNanchor_3" href="#Footnote_3" class="fnanchor">[3]</a> is useless. In physiology the witness test is -indispensable.</p> -<p><span class="pagenum" id="Page_51">[Pg 51]</span></p> -<p><i>Generality of Vital Phenomena.</i>—If we add that -Claude Bernard opposed the narrow opinion, so dear -to early medicine, which limited the consideration of -vitality to man, and the contrary notion of the essential -generality of the phenomena of life from man to the -animal, and from the animal to the plant, we shall -have given very briefly an idea of the kind of revolution -which was accomplished about the year 1864, the -date of the appearance of the celebrated <i>l’Introduction -à la médecine expérimentale</i>.</p> - -<p>The ideas we have just recalled seem to be as -evident as they are simple. These principles appear -so well founded that in a measure they form an integral -part of contemporary mentality. What scientist -would nowadays deliberately venture to explain some -biological fact by the intervention of the evidently -inadequate vital force or final cause? And who, to<span class="pagenum" id="Page_52">[Pg 52]</span> -account for the apparent inconsistency of the result, -would bring forward the “caprice” of living nature? -And who again would openly dispute the utility of -the comparative method?</p> - -<p>What the physiologists of to-day, according to -Claude Bernard, would no longer do, their predecessors -would do, and not the least important of -them. Longet, for example, at a full meeting of the -Académie, apropos of recurrent sensibility, and Colin -(of Alfort), communicating his statistical results on -the temperature of two hearts, accepted more or -less explicitly the indetermination of vital facts. And -why confine our remarks to our predecessors? The -scientists of to-day are much the same. So here -again we see the reappearance of the phantom of -the final cause in so-called scientific explanations. -One fact is accounted for by the necessity of the -self-defence of the organism; another by the necessity -to a warm-blooded animal of keeping its temperature -constant. Le Dantec has recently reproached zoologists -for giving as an explanation of fecundation -the advantage that an animal enjoys in having a -double line of ancestors. We might as well say, as -L. Errera has pointed out, that the inundations of the -Nile occur in order to bring fertility to Egypt.</p> - -<p>We must not therefore depreciate the marvellous -work which has emancipated modern physiology from -the tutelage of early theories. The witnesses of this -revolution appreciated its importance. One of them -remarked as follows, on the appearance of <i>l’Introduction -à la médecine expérimentale</i>, which contained, -however, only a portion of the theory:—“Nothing -more luminous, more complete, or more profound, has -ever been written upon the true principles of an art so<span class="pagenum" id="Page_53">[Pg 53]</span> -difficult as that of experiment. This book is scarcely -known because it is on a level to which few people -nowadays attain. The influence it will have on medical -science, on its progress, and on its very language, -will be enormous. I cannot now prove my assertion, -but the reading of this book will leave so strong an -impression that I cannot help thinking that a new -spirit will at once inspire these splendid researches.” -This was said by Pasteur in 1866. That is what he -thought of the work of his senior and his rival, at the -moment when he himself was about to inspire those -“splendid researches” with the movement of reform, -the importance and the consequences of which have -no equivalent in the history of science. By their -discoveries and their teaching, by their examples and -their principles, Claude Bernard and Pasteur have -succeeded in emancipating a portion of the domain of -vital facts from the direct intervention of hypothetical -agents and first causes. They were compelled, however, -to leave to philosophical speculation, to directing -forces, to animism, to vitalism, an immense provisory -field, the field which corresponds to the functions of -generation and of development, to the life of the -species and to its variations. Here we find them -again in various disguises.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_54">[Pg 54]</span></p> - -<h2 class="nobreak" id="BOOK_II">BOOK II.<br /> - - -<small>THE DOCTRINE OF ENERGY AND THE LIVING -WORLD.</small></h2></div> - - -<p class="prel">Summary: General Ideas of Life.—Elementary Life.—Chapter -I. Energy in General.—Chapter II. Energy in Biology.—Chapter -III. Alimentary Energetics.</p> - - -<p class="center">GENERAL IDEAS OF LIFE. ELEMENTARY LIFE.</p> - - -<p><i>Life is the Sum-total of the Phenomena Common -to all Living Beings. Elementary Life.</i>—Living -beings differ more in form and configuration than -in their manner of being. They are distinguished -more by their anatomy than by their physiology. -There are, in fact, phenomena common to all, from -the highest to the lowest. This is because there is -that similar or identical foundation, that <i>quid commune</i> -which has enabled us to apply to them the common -name of “living beings.” Claude Bernard gave to -this sum-total of manifestations common to all (nutrition, -reproduction) the name of <i>elementary life</i>. To -him <i>general physiology</i> was <i>the study of elementary -life</i>; the two expressions were equivalent, and they -were equivalent to a longer formula which the -illustrious biologist has given as a title to one of -his most celebrated works—<i>The Study of the -Phenomena Common to all Living Beings, Animals,<span class="pagenum" id="Page_55">[Pg 55]</span> -and Plants</i>. From this point of view each being is -distinguished from another being as a given <i>individual</i> -and as a particular <i>species</i>; but all are in some way -alike and thus resemble one another: common life, -elementary life, the essential phenomena of life; it is -<i>life itself</i>.<a id="FNanchor_4" href="#Footnote_4" class="fnanchor">[4]</a></p> - -<p>The manifestations of life may therefore be regarded -from the point of view of what is most general among -them. As we go down the scale of anatomical organization, -as we pass from apparatus (circulatory, -digestive, respiratory, nervous) to the <i>organs</i> which -compose them, from the organs to the <i>tissues</i>, and -finally from the tissues to the <i>anatomical elements</i> or -<i>cells</i> of which they are formed, we approach that -common, physiological dynamism which is <i>elementary -life</i>, but we do not actually reach it. The cell, the -anatomical element, is still a complicated structure. -The elementary fact is further from us and lower -down. It is in the living matter, in the molecule of -this matter, and there we must seek it.</p> - -<p>Galen gave in days gone by as the object of -researches on life, the knowledge of the use of the -different organs of the animal machine; “de usu -partium.” Later, Bichat assigned to them as their -end the determination of the <i>properties of tissues</i>. -Modern anatomists and zoologists try to reach the -constituent element of these tissue—the cell. Their -dream is to construct a <i>cellular physiology</i>, a <i>physiological -cytology</i>; but we must go further than that.</p> -<p><span class="pagenum" id="Page_56">[Pg 56]</span></p> -<p><i>General Physiology, Cellular Physiology, the -Energetics of Living Beings.</i>—General physiology, -as was taught by Pflüger and his school, claims -to go deeper down than the apparatus, or the -organ, or even the cell. As in the case of -physics, general physiology endeavours to reach, -and really does in many cases reach, as far as -the molecule. It is not cellular, it is <i>molecular</i>. -Already, in fact, the efforts of modern science have -succeeded in penetrating into the most general phenomena -of the living being—those attributable to living -matter, or, to speak more clearly, those which result -from the play of the universal laws of matter at work -in this particular medium which is the organized -being.</p> - -<p>Robert Mayer and Helmholtz have the honour of -having set physiology in the right road. They -founded <i>the energetics of living beings</i>—<i>i.e.</i>, they -regarded the phenomena of life from the point of -view of energy, which is the factor of all the phenomena -of the universe.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_57">[Pg 57]</span></p> - -<h3 class="nobreak" id="CHAPTER_I_2">CHAPTER I.<br /> - -<small>ENERGY IN GENERAL.</small></h3></div> - - -<p class="prel">Origin of the Idea of Energy.—The Phenomena of Nature bring -into play only two Elements, Matter and Energy.—§ 1. -Matter.—§ 2. Energy.—§ 3. Mechanical Energy.—§ 4. -Thermal Energy.—§ 5. Chemical Energy.—§ 6. The Transformations -of Energy.—§ 7. The Principles of Energetics.—The -Principle of the Conservation of Energy.—§ 8. Carnot’s -Principle.—The Degradation of Energy.</p> - - - -<p><i>Origin of the Idea of Energy.</i>—A new term, namely -<i>energy</i>, has been for some years introduced into natural -science, and has ever since assumed a more and more -important place. It is owing to the English physicists, -and especially to the English electrical engineers, that -this expression has made its way into technology, an -expression which is part and parcel of both languages, -and which has the same meaning in both. The idea -it expresses is, in fact, of infinite value in industrial -applications, and that is why its use has gradually -spread and become generalized. But it is not merely -a practical idea. It is above all a theoretical idea of -capital importance to pure theory. It has become -the point of departure of a science, <i>energetics</i>, which, -although born but yesterday, already claims to -embrace, co-ordinate, and blend within itself all the -other sciences of physical and living nature, which the -imperfection of our knowledge alone had hitherto -kept distinct and apart.</p> - -<p><span class="pagenum" id="Page_58">[Pg 58]</span></p> - -<p>On the threshold of this new science we find inscribed -<i>the principle of the conservation of energy</i>, -which has been presented to us by some as Nature’s -supreme law, and which we may say dominates -natural philosophy. Its discovery marked a new era -and accomplished a profound revolution in our conception -of the universe. It is due to a doctor, Robert -Mayer, who practised in a little town in Wurtemberg, -and who formulated the new principle in 1842, and -afterwards developed its consequences in a series of -publications between 1845 and 1851. They remained -almost unknown until Helmholtz, in his celebrated -memoir on the conservation of force, brought them to -light and gave them the importance they deserved. -From that time forward the name of the doctor of -Heilbronn, until then obscure, has taken its place -among the most honoured names in the history of -science.<a id="FNanchor_5" href="#Footnote_5" class="fnanchor">[5]</a></p> -<p><span class="pagenum" id="Page_59">[Pg 59]</span></p> -<p>As for <i>energetics</i>, of which thermodynamics is only -a section, it is agreed that even if it cannot forthwith -absorb mechanics, astronomy, physics, chemistry, and -physiology, and build up that general science which -will be in the future the one and only science of -nature, it furnishes a preparation for that ideal state, -and is a first step in the ascent to definite progress.</p> - -<p>Here I propose to expound these new ideas, in so -far as they contain anything universally accessible; -and in the second place, I propose to show their -application to physiology—that is to say, to point out -their rôle and their influence in the phenomena of -life.</p> - -<p><i>Postulate: the Phenomena of Nature bring into -play only two Elements, Matter and Energy.</i>—If we -try to account for the phenomena of the universe, -we must admit with most physicists that they -bring into play two elements, and two elements only; -namely, <i>matter</i> and <i>energy</i>. All manifestations are -exhibited in one or other of these two forms. This, -we may say, is the postulate of experimental science.</p> - -<p>Just as gold, lead, oxygen, the metalloids, and the -metals are different kinds of matter, so it has been -recognized that sound, light, heat, and generally, the -imponderable agents of the days of early physics, are<span class="pagenum" id="Page_60">[Pg 60]</span> -different varieties of energy. The first of these ideas -is older and more familiar to us, but it has not for that -reason a more certain existence. Energy is objective -reality for the same reason that matter is. The -latter certainly appears more tangible and more easily -grasped by the senses. But, upon reflection, we are -assured that the best proof of their existence, in both -cases, is given by the law of their conservation—that -is to say, their persistence in subsisting.</p> - -<p>The objective existence of matter and that of -energy will therefore be taken here as a postulate of -physical science. Metaphysicians may discuss them. -We have but little room for such a discussion.</p> - - -<h4>§ I. <span class="smcap">Matter.</span></h4> - -<p>It is certainly difficult to give a definition of -matter which will satisfy both physicists and metaphysicians.</p> - -<p><i>Mechanical Explanation of the Universe. Matter is -Mass.</i>—Physicists have a tendency to consider all -natural phenomena from the point of view of mechanics. -They believe that there is a mechanical explanation -of the universe. They are always on the look out for -it, implicitly or explicitly. They endeavour to reduce -each category of physical facts to the type of the facts -of mechanics. They have made up their minds to see -nowhere anything but the play of motion and force. -Astronomy is celestial mechanics. Acoustics is the -mechanics of the vibratory movements of the air or of -sonorous bodies. Physical optics has become the -mechanics of the undulations of the ether, after having -been the mechanics of emission—a wonderful<span class="pagenum" id="Page_61">[Pg 61]</span> -mechanics which represents exactly all the phenomena -of light, and furnishes us with a perfect objective -image of it. Heat, in its turn, has been reduced to a -mode of motion, and thermodynamics claims to embrace -all its manifestations. As early as 1812, Sir -Humphry Davy wrote as follows:—“The immediate -cause of heat is motion, and the laws of transmission -are precisely the same as those of the transmission -of motion.” From that time forth, this conception -developed into what is really a science. The constitution -of gases has been conceived by means of two -elements—particles, and the motions of these particles, -determined in the strictest detail. And finally, in spite -of the difficulties of the representation of electrical and -magnetic phenomena after Ampère and before Maxwell -and Hertz, physicists have been able to announce in the -second half of the nineteenth century the unity of the -physical forces realized in and by mechanics. From -that time forth, all phenomena have been conceived -as motion or modes of motion, only differing essentially -one from the other in so far as motions may -differ—that is to say, in the masses of the moving -particles, their velocities, and their trajectories. The -external world has appeared essentially homogeneous; -it has fallen a prize to mechanics. Above all, there -is heterogeneity in ourselves. It is in the brain, -which responds to the nervous influx engendered by -the longitudinal vibration of the air, by the specific -sensation of sound, which responds to the transverse -vibration of the ether by a luminous sensation, and in -general to each form of motion by an irreducible -specific sensation.</p> - -<p>Forty years have passed since the mechanical explanation -of the universe reached its definite and<span class="pagenum" id="Page_62">[Pg 62]</span> -perfect form. It dominates physics under the name -of the <i>theory of kinetic energy</i>. The minds of men in -our own time are so strongly impregnated with this -idea that most scientists of ordinary culture get no -glimpse of the world of phenomena but by means of -this conception. And yet it is only an hypothesis. -But it is so simple, so intuitive, and appears to be so -thoroughly verified by experiment, that we have -ceased to recognize its arbitrary and unnecessarily -contingent character. Many physicists from this -standpoint consider the kinetic theory as an imperishable -monument.</p> - -<p>However, as in the case of H. Poincaré, the most -eminent physicists and mathematicians are not the -dupes of this system; and without failing to recognize -the immense services which it has rendered to science, -they are perfectly well aware that it is only a system, -and that there may be other systems. Certain among -them, such as Ostwald, Mach, and Duhem, believe -that the monument is showing signs of decay, and at -present the theory is opposed by another theory—namely, -the theory of <i>energy</i>.</p> - -<p>The theory of <i>energy</i> is usually considered and presented -as a consequence of the kinetic theory; but it -is perfectly independent of it, and it is, in fact, without -relying on the kinetic theory, without assuming the -unity of physical forces, which are combined in molecular -mechanics, that we shall expound the general -system.</p> - -<p>This is not the point at issue for the moment. It is -not a question of deciding the reality or the merit of -this or that mechanical explanation; it is a question -of something more general, because upon it depends -the <i>idea of matter</i>. It is a question of knowing if<span class="pagenum" id="Page_63">[Pg 63]</span> -there are any explanations other than mechanical. -The illustrious English physicist, Lord Kelvin, does -not seem willing to admit this. “I am never satisfied,” -he said, in his <i>Molecular Mechanics</i>, “until I have -made a mechanical model of the object. If I can -make this model, I understand; if I cannot, I do not -understand.”</p> - -<p>This tendency of so vigorous a mind to be content -only with mechanical explanations, has been -that of the majority of scientific men up to the -present day, and from it has arisen the scientific idea -of matter.</p> - -<p>What is matter, in fact, to the student of mechanics? -It is mass. All mechanics is constructed of masses -and forces. Laplace said: “The mass of a body is the -sum of its material points.” To Poisson, mass is the -quantity of matter of which a body is composed. -Matter is therefore confused with mass. Now, mass -is the characteristic of the motion of a body under the -action of a given force; it defines obedience or resistance -to the causes of motion; it is the <i>mechanical -parameter</i>; it is the co-efficient proper to every mobile -body; it is the first <i>invariant</i> of which a conception -has been established by science.</p> - -<p>In fact, the word matter appears to be used in -other senses by physicists, but this is only apparently -so. They have but broadened the idea of the -mechanicians. They have characterized matter by -the whole series of phenomenal manifestations which -are <i>proportional to mass</i>, such as weight, volume, -chemical properties—so that we may say that the -notion of matter does not intervene scientifically with -a different signification from that of mass.</p> - -<p><i>Two kinds of Matter. Ponderable and Imponder<span class="pagenum" id="Page_64">[Pg 64]</span>able.</i>—In -physics we distinguish between two kinds -of matter—ponderable, obeying the law of universal -attraction or weight, and imponderable matter or -ether, which we assume to exist and to escape the -action of that force. Ether has no weight, or extremely -little weight. It is material in so far as it -has mass. It is its mass which confers existence on -it from the mechanical point of view—a logical existence, -inferred from the necessity of explaining the -propagation of heat, light, or electricity.</p> - -<p>It may be observed that the use of mass really -comes to bringing another element, force, to intervene, -and we shall see that force is connected with energy; -thus it comes to defining matter indirectly by energy. -The two fundamental elements are not therefore -irreducible; on the contrary, they should be one and -the same thing.</p> - -<p><i>Energy is the only Objective Reality.</i>—This fusion -into one will become more evident still when we -examine the different kinds of energy, each of which -exactly corresponds to one of the aspects of active -matter. Shall we define matter by <i>extension</i>, by the -portion of space it occupies, as certain philosophers -do? The physicist will answer that space is only -known to us by the expenditure of energy necessary -to penetrate it (the activity of our different senses). -And then what is weight? It is <i>energy of position</i> -(universal attraction). And so with the other attributes. -So that if matter were separated from the -energetic phenomena by means of which it is revealed -to us—weight or energy of position, impenetrability -or energy of volume, chemical properties or chemical -energies, mass or capacity for kinetic energy—the very -idea of matter would vanish. And that comes to<span class="pagenum" id="Page_65">[Pg 65]</span> -saying that fundamentally there is only one objective -reality, <i>energy</i>.</p> - -<p><i>Philosophical Point of View.</i>—But from the philosophical -point of view are there objective realities? -That is a wider question which throws doubt upon -matter itself, and which it is not our place to investigate -here. A metaphysician may always discuss and -deny the existence of the objective world. It may be -maintained that man knows nothing beyond his -sensations, and that he only objectivates them and -projects them outside himself by a kind of hereditary -illusion. We must avoid taking sides in all these -difficulties. Physics for the moment ignores them—<i>i.e.</i>, -postpones their consideration.</p> - -<p>In a first approximation we agree to consider -ponderable matter only. Chemistry acquaints us -with its different forms. They are the different -simple bodies, metalloids, metals, and the compound -bodies, mineral or organic. Hence we may say that -chemistry is <i>the history of the transformations of -matter</i>. From the time of Lavoisier this science has -followed the transformations of matter, balance in -hand, and ascertains that they are accomplished -without change of weight.</p> - -<p><i>Law of the Conservation of Matter.</i>—Imagine a -system of bodies enclosed in a closed vessel, and the -vessel placed in the scale of a balance. All the -chemical reactions capable of completely modifying -the state of this system have no effect upon the scale -of the balance. The total weight is the same before, -during, and after. It is precisely this equality of -weight which is expressed in all the equations with -which treatises on chemistry are filled.</p> - -<p>From a higher point of view we recognize here, in<span class="pagenum" id="Page_66">[Pg 66]</span> -this <i>law of Lavoisier</i> or of the <i>conservation of weight</i>, -the verification of one of the great laws of nature -which we extend to every kind of matter, ponderable -or not. It is the <i>law of the conservation of matter</i>, -or again, of the indestructibility of matter—“Nothing -is lost, nothing is created, all is transformation.” This -is exactly what Tait held, this impossibility of creating -or destroying matter which at the same time is a -proof of its objective existence. This indestructibility -of ponderable matter is at the same time the fundamental -basis of chemistry. Chemical analysis could -not exist if the chemist were not sure that the contents -of his vessel at the end of his operations ought to be -quantitatively, that is to say by weight, the same as at -the beginning, and during the whole course of the -experiment.<a id="FNanchor_6" href="#Footnote_6" class="fnanchor">[6]</a></p> -<p><span class="pagenum" id="Page_67">[Pg 67]</span></p> - -<h4>§ 2. <span class="smcap">Energy.</span></h4> - -<p><i>The Idea of Energy Derived from the Kinetic -Theory.</i>—The notion of energy is not less clear than -the notion of matter, it is only more novel to our -minds. We are led to it by the mechanical conception -which now dominates the whole of physics, <i>the kinetic -conception</i>, according to which in the sensible universe -there are no phenomena but those of motion. Heat, -sound, light, with all their manifestations so complex -and so varied, may, according to this theory, be -explained by motion. But then, if outside the brain -and the mind which has consciousness and which -perceives, Nature really offers us only motion, it -follows that all phenomena are essentially homogenous -among one another, and that their apparent -heterogeneity is only the result of the intervention of -our sensorium. They differ only in so far as movements -are capable of differing—that is to say, in -velocity, mass, and trajectory. There is something -fundamental which is common to them and this <i>quid -commune</i> is <i>energy</i>. Thus the idea of energy may be -derived from the kinetic conception, and this is the -usual method of exposition.</p> - -<p>This method has the great inconvenience of causing -an idea which lays claim to reality to depend upon an -hypothesis. And besides that, it gives a view of it -which may be false. It makes of the different forms -of energy something more than varieties which are -equivalent to one another. It makes of them <i>one and -the same thing</i>. It blends into one the modalities of -energy and mechanical energy. For the experimental -idea of equivalence, the kinetic theory substitutes the -arbitrary idea of the equality, the blending, and the -fundamental homogeneity of phenomena. This no -doubt is how the founders of energetics, Helmholtz, -Clausius, and Lord Kelvin understood things. But a -more attentive study and a more scrupulous determination -not to go beyond the teaching of experiment -should compel us to reform this manner of looking at -it. And it is Ostwald’s merit that, after Hamilton, he -insisted on this truth—that the various kinds of -physical magnitudes furnished by the observation of -phenomena are different and characteristic. In particular, -we may distinguish among them those which -belong to the order of <i>scalar</i> magnitudes and others -which are of the order of <i>vector</i> magnitudes.</p> - -<p><i>The Idea of Energy derived from the Connection -of Phenomena.</i>—The idea of energy is not absolutely<span class="pagenum" id="Page_68">[Pg 68]</span> -connected with the kinetic theory, and it should not -be exposed therefore to the vicissitudes experienced -by that theory. It is of a higher order of truth. We -can derive it from a less unsafe idea, namely that of -the <i>connection of natural phenomena</i>. To conceive it -we must get accustomed to this primordial truth, that -there are no <i>phenomena isolated</i> in time and space. -This statement contains the whole point of view of -energetics.</p> - -<p>The physics of early days had only an incomplete -view of things, for it considered phenomena independently -the one of the other.</p> - -<p>Phenomena for purposes of analysis were classed in -separate and distinct compartments: weight, heat, -electricity, magnetism, light. Each phenomenon was -studied without reference to that it succeeded or that -which should follow. Nothing could be more artificial -than such a method as this. In fact, there is a -sequence in everything, everything is connected up, -<i>everything precedes and succeeds in nature</i>—in nature -there are only series. The isolated fact without -antecedent or consequent is a myth. Each -phenomenal manifestation is in solidarity with -another. It is a metamorphosis of one state of -things into another. It is transformation. It implies -a state of things anterior to that which we are -observing, a phenomenal form which has preceded -the form of the present moment.</p> - -<p>Now there exists a link between the anterior state -and the succeeding state—that is to say, between the -new form which is appearing and the preceding form -which is disappearing. The science of energy shows -that something has passed from the first condition to -the second, but covering itself as it were with a new<span class="pagenum" id="Page_69">[Pg 69]</span> -garment; in a word, that something active and -permanent subsists in the passage from one condition -to another, and that what has changed is only the -aspect, the appearance.</p> - -<p>This constant something which is perceived beneath -the inconstancy and the variety of forms, and which -circulates in a certain manner from the antecedent -phenomenon to its successor, is energy.</p> - -<p>But still this is only a very vague view, and it may -seem arbitrary. It may be made more exact by -examples borrowed from the different categories of -natural phenomena. There are energetic modalities -in relation with the different phenomenal modalities. -The different orders of phenomena which may be -presented—mechanical, chemical, thermal, electrical—give -rise to corresponding forms of energy.</p> - -<p>When to a mechanical phenomenon succeeds a -mechanical, thermal, or electrical phenomenon, we -say, embracing transformation in its totality, that -there has been a transformation of mechanical energy -into another form of energy, mechanical, thermal, or -electrical, etc.</p> - -<p>This idea becomes more precise if we examine -successively each of these cases and the laws which -regulate them.</p> - - -<h4>§ 3. <span class="smcap">Mechanical Energy.</span></h4> - -<p>Mechanical energy is the simplest and the oldest -known.</p> - -<p><i>Mechanical Elements: Time, Space, Force, Work, -Power.</i>—Mechanical phenomena may be considered -under two fundamental conditions—<i>time</i> and <i>space</i>,<span class="pagenum" id="Page_70">[Pg 70]</span> -which are, in a measure, logical elements, to which -may be joined a third element, itself experimental, -having its foundations in our sensations—namely, -<i>force</i>, <i>work</i>, or <i>power</i>.</p> - -<p>The ideas of force, work, and power, are drawn from -the experience man has of his muscular activity. -Nevertheless the greatest mathematical minds from -from Descartes to Leibniz have been obliged to define -and explain them clearly.</p> - -<p><i>Force</i>.—The prototype of force is weight, universal -attraction. Experiment shows us that every body -falls as long as no obstacle opposes its fall. This is -so universal a property of matter that it serves to -define it. The <i>force</i>, weight, is therefore the name -given to the cause of the fall of the bodies.</p> - -<p>Force in general is the <i>cause of motion</i>. Hence -force exists only in so far as there is motion. There -would be no force without action. This is Newton’s -point of view. It did not prevail, and was not the -point of view of his successors. The name of force -has been given not only to the cause which produces -or modifies motion, but to the cause which resists and -prevents it. And then not only have <i>forces in action</i> -been considered (dynamics), but <i>forces at rest</i> (statics). -Now, to Newton there was no statics. Forces do not -continue to exist when they produce no motion; they -are not in equilibrium, they are destroyed.</p> - -<p>The idea of force therefore is a metaphysical idea -which contains the idea of <i>cause</i>. But it becomes -experimental immediately it is looked upon as resisting -motion, according to the point of view of Newton’s -opponents. Its foundations lie in the muscular -activity of man.</p> - -<p>Man can support a burden without bending or<span class="pagenum" id="Page_71">[Pg 71]</span> -moving. This burden is a weight—that is to say, a -mass acted on by the force of weight. Man resists -this force so as to prevent its effect. If it were not -annihilated by man’s <i>effort</i>, this effect would be the -motion or the fall of the heavy body. The <i>effort</i> and -the force are thus in equilibrium, and the effort is -equal and opposite to the force. It gives to the man -who exercises it the conscious idea of <i>force</i>. Thus we -know of force through effort. Every clear idea that -we can have of <i>force</i> springs from the observation of -our muscular effort.</p> - -<p>The notion of force is thus an anthropomorphic -notion. When an effect is produced in nature outside -human intervention, we say that it is by something -analogous to what in man is effort, and we give to this -something a name which is also analogous, namely -<i>force</i>. To give a name to <i>effort</i> and to compare -efforts in magnitude, we need not know all about -them, nor need we know in what they essentially -consist, of what series of physical, chemical, and -physiological actions they are the consequence. And -so it is with force. It is a resistance to motion or -the cause of motion. This cause of motion may be -an anterior motion (kinetic force). It may be an -anterior physical energy (physical and chemical -forces).</p> - -<p>Forces are measured in the C.G.S. system by comparing -them with the unit called the Dyne.<a id="FNanchor_7" href="#Footnote_7" class="fnanchor">[7]</a> In -practice they are compared with a much larger unit—the -gramme, which is the weight, the force acting on -a unit of mass of one centimetre of distilled water at -a temperature of 4° C.</p> -<p><span class="pagenum" id="Page_72">[Pg 72]</span></p> - -<p><i>Work.</i>—The muscular activity of man may be -brought into play in yet another manner. When we -employ workmen, as Carnot said in his <i>Essai sur -l’équilibre et le mouvement</i>, it is not a question of -“knowing the burdens that they can carry without -moving from their position,” but rather the burdens -that they can carry from one point to another. For -instance, a workman may have to lift the water from -the bottom of a well to a given height, and the case is -the same for the animals we employ. “This is what -we understand by force when we say that the force of -a horse is equal to the force of seven men. We do -not mean that if seven men were pulling in one -direction and the horse in another that there would be -equilibrium, but that in a piece of work the horse -alone would lift, for example, as much water from the -bottom of a well to a given height as the seven men -together would do in the same time.”<a id="FNanchor_8" href="#Footnote_8" class="fnanchor">[8]</a></p> - -<p>Here, then, we have to do with the second form of -muscular activity, which is called in mechanics, “work”—at -least, if in the preceding quotation we attach no -particular importance to the words “in the same -time,” and retain the employment of muscular activity -only “under constant conditions.” Mechanical work -is compared with the elevation of a certain weight to a -certain height. It is measured by the product of the -force (understood in the sense in which it was used -just now—that is to say, as causing or resisting motion) -and the displacement due to this motion. The unit is -the Kilogrammetre—that is to say, the work necessary -to lift a weight of one kilogramme to the height of -one metre.</p> -<p><span class="pagenum" id="Page_73">[Pg 73]</span></p> -<p>It will be remarked that the idea of time does not -intervene in our estimation of work. The notion of -work is independent of the ideas of velocity and -time. “The greater or less time that we take to do -a piece of work is of no more assistance in measuring -its magnitude than the number of years that -a man may have taken to grow rich or to ruin himself -can help to estimate the present amount of his -fortune.”</p> - -<p>Going back to Carnot’s comparison, an employer -who employed his workmen only on piece-work,—that -is to say, who would only care about the amount of -work done, and would be indifferent to the time that -they took over it,—would be at the same point of view -as the advocates of the mechanical theory. M. -Bouasse, whom we follow here, has remarked that this -idea of mechanical work may be traced back to -Descartes. His predecessors, and Galileo in particular, -had quite a different idea of the way in which -mechanical activity should be measured; and so, -among the mathematicians of the eighteenth century, -Leibniz and, later, John Bernoulli were almost alone -in looking at it from this point of view.</p> - -<p><i>Energy.</i>—Work thus understood is <i>mechanical -energy</i>. It represents the lasting and objective effect -of the mechanical activity independent of all the circumstances -under which it was carried out. The -same work may be done under very different conditions -of time, velocity, force, and displacement. -It is therefore the permanent element in the variety of -mechanical aspects. Work, for example, in the -collision of bodies when the motion of a body appears -to be destroyed on impact with another, reappears as -indestructible <i>vis viva</i>. This, then, is exactly what<span class="pagenum" id="Page_74">[Pg 74]</span> -we call <i>energy</i>; and if we agree to give it this name, -we may say that the conservation of energy is -invariable throughout all mechanical transformations.</p> - -<p><i>Distinction between Work and Force, and between -Energy and Work.</i>—The history of mechanics shows -us what trouble has been taken and what efforts have -been made to distinguish work (now mechanical -energy) from force.</p> - -<p>It is worth while insisting on this distinction. It -could be easily shown that force has no objective existence. -It has no duration, no permanence. It does -not survive its effect, motion. There is no conservation -of force. It passes instantly from infinity to -zero. It is a <i>vectorial magnitude</i>—that is to say, it -involves the idea of direction. Work, on the other -hand, is the real element; it is a <i>scalar magnitude</i> -involving the idea of opposite directions, indicated by -the signs + and-. Work and force are heterogeneous -magnitudes. Energy, and this is the only -characteristic by which it is distinguished from work, -is an <i>absolute magnitude</i> to which we may not even -give opposite signs.</p> - -<p>An example may perhaps throw these characteristics -into relief—namely, the hydraulic press. We have on -the platform exactly the work which has been done -on the other side. The machine has only made it -change its form. On the contrary, the force has been -infinitely multiplied. We may, in fact, consider an -infinite number of surfaces equal to that of a small -piston, placed and orientated at will within the liquid; -each, according to Pascal’s principle, will support a -pressure equal to that which is exercised. As soon as -we cease to support it, this infinity falls at once to zero.<span class="pagenum" id="Page_75">[Pg 75]</span> -Now what real thing could pass instantly from infinity -to zero?</p> - -<p>That skilful and very able physiologist, M. Chauveau, -has endeavoured to use the same term <i>energy of contraction</i> -for the two phenomena of effort (force) and -work. It seems, however, from the point of view of -the expenditure imposed on the organism, that these -two modes of activity, <i>static contraction</i> (effort), and -<i>dynamical contraction</i> (work), may be, in fact, perfectly -comparable. But although this manner of conceiving -the phenomena may certainly be exact, and may be -of great value, the idea of force must none the less -remain distinct from that of work. The persistence -of the author in violating established custom in this -connection has prevented him from enabling mechanicians -and even some physiologists to understand and -accept very useful truths.</p> - -<p><i>Power.</i>—The idea of mechanical <i>power</i> differs from -those of force and work. The idea of time must -intervene. It is not sufficient, in fact, in order to -characterize a mechanical operation, to point to the -task accomplished. It may be necessary or useful to -know how much time it required. This is true, -especially when we are concerned with the circumstances -as well as the results of the performance of -the work; and this is the case when we wish to -compare machines. We say that the machine which -does the work in the shortest space of time is -the most powerful. The unit of power is the Kilogrammetre-second—that -is to say, the power of a -machine which does a kilogrammetre in a second. In -manufactures we generally employ a unit 75 times -greater than this—a <i>horse-power</i>. This is the power of -a machine which does 75 kilogrammetres a second.<span class="pagenum" id="Page_76">[Pg 76]</span> -In the electrical industry we measure by <i>kilowatts</i>, -which are equivalent to 1.36 horse power, or by a <i>watt</i>, -a unit a thousand times smaller.</p> - -<p>Let us add that the power of a machine is not an -absolute and permanent characteristic of the machine. -It depends on the circumstances under which the -work is carried out, and that is why, in particular, we -cannot appreciate the power of the human machine in -comparison with industrial machines. Experience -has shown that the mechanical power of living beings -depends upon the nature of the work they are doing. -In this connection we may mention some very interesting -experiments communicated to the Institute, in -the year VI., by the celebrated physicist, Coulomb. A -man of the average weight of 70 kilogrammes was -made to climb the stairs of a house 20 metres high. -He ascended at the rate of 14 metres a minute, and -he performed this daily task for four effective hours. -This work was equivalent to 235,000 kilogrammetres. -But if, instead of climbing without a burden, the same -man had had to carry a load, the result would have -been quite different. Coulomb’s workman took up -six loads of wood a day to a height of 12 metres -in 66 journeys, corresponding to a maximum -work of 109,000 instead of 235,000 kilogrammetres. -The mechanical power of the human machine -thus varied in the two cases in the ratio of 235 -to 109.</p> - -<p><i>The Two Aspects of Mechanical Energy: Kinetic -and Potential.</i>—Energy, or mechanical work, may -present itself in two forms—kinetic energy, corresponding -to the mechanical phenomenon which has -really taken place, and <i>potential energy</i>, or the energy -of reserve.</p> - -<p><span class="pagenum" id="Page_77">[Pg 77]</span></p> - -<p>A body which has been raised to a certain -height will, if it be let fall, perform work which -can be exactly measured in kilogrammetres by the -product of its weight into the height it falls. Such -work may be utilized in many ways. In this way, -for instance, public clocks are worked. Now, as long -as the clock-weight is raised and not let go, and -as long as it is motionless, the physics of early -days would say that there is nothing to discuss; -the phenomenon is the fall; it is going to take -place, but at the present moment there has been -no fall.</p> - -<p>In energetics we do not reason in this way. We -say that the body possesses a <i>capacity for work</i> which -will be manifested when the opportunity arises, a -storage of energy, a virtual or <i>potential energy</i>, or -again, an <i>energy of position</i>, which will be transformed -into actual energy or real work as soon as the body -falls.</p> - -<p>Let us ask whence this energy arises. It proceeds -from the previous operation which has raised the -weight from the surface of the soil to the position it -occupies. For example, if it is a question of the -weights of a public clock, which, by its fall, will develop -in 15 days the work that is necessary to turn the -wheels, to strike the bell, and to turn the hands, -this work ought to bring to our minds the exactly equal -and opposite work done by the clockmaker, who has -to carry the clock-weight and to lift it up from the -ground to its point of departure. The work of the -fall is the faithful counterpart of the work of elevation. -The phenomenon has therefore in reality two phases. -We find in the second exactly what was put into the -first, the same quantity of energy—<i>i.e.</i>, the same work.<span class="pagenum" id="Page_78">[Pg 78]</span> -Between these phases comes the intermediary phase -of which we say that it is a period of virtual <i>or potential -energy</i>. This is a way of remembering in some -measure the preceding phenomenon—<i>i.e.</i>, the work of -lifting up, and of indicating the phenomena which will -follow—<i>i.e.</i>, the work of the fall. And thus we connect -by our thoughts the present situation with the antecedent -and with the consequent position, and it is -from this consideration of continuity alone that the -conception of energy springs—that is to say, of something -which is conserved and is found to be permanent -in the succession of phenomena. This energy of -which we lose no trace does not appear to us new -when it is manifested. Our imagination eventually -materializes the idea of it. We follow it as a real -thing, having an objective existence, which is asleep -during the latent potential period, and is revealed or -manifested later.</p> - -<p>Among other examples, that of the coiled spring -which is unwound is particularly suitable for showing -this fundamental character of the idea of -mechanical energy, an idea which is the clearest -of all. Machines are only transformers and not -creators of mechanical energy. They only change -one form into another.</p> - -<p>In the same way, too, a stream of water or the -torrent of a mountainous region may be utilized for -setting in motion the wheels and the turbines of the -factories situated in the valley. Its descent produces -the mechanical work which would be a creation <i>ex -nihilo</i> if we do not connect the phenomenon with its -antecedents. We look on it as a simple restitution, if -we think of the origin of this water which has been -transported and lifted in some way to its level by the<span class="pagenum" id="Page_79">[Pg 79]</span> -play of natural forces—evaporation under the action -of the sun, the formation of clouds, transport by winds, -etc. And we here again see that a complex energy -has been transformed, in its first phenomenal condition, -into <i>potential energy</i>, and that this potential -energy is always expended in the second phase without -loss or gain.</p> - -<p><i>The Different Kinds of Mechanical Energy; of -Motion, of Position.</i>—There are as many forms of -energy as there are distinct categories of phenomena -or of varieties in these categories. Physicists distinguish -between two kinds of mechanical energy—energy -of motion and energy of position. The energy -of position presents several variants—energy of distance, -which corresponds to force: of this we have just -spoken; energy of surface, which corresponds to particular -phenomena of surface tension; and energy of -volume which corresponds to the phenomena of pressure. -Energy of motion, <i>kinetic energy</i>, is measured in two -ways: as work (the product of force and displacement, -W = <i>fs</i>) or as <i>vis viva</i> (half the product of the mass -into the square of the velocity U = <i>mv<sup>2</sup></i>∕2.<a id="FNanchor_9" href="#Footnote_9" class="fnanchor">[9]</a></p> -<p><span class="pagenum" id="Page_80">[Pg 80]</span></p> - -<h4>§ 4. <span class="smcap">Thermal Energy.</span></h4> - -<p>In the elements of physics it is nowadays taught -that mechanical work may be transformed into heat, -and reciprocally that heat may be transformed into -mechanical work. Friction, impact, pressure, and -expansion destroy or annihilate the mechanical energy -communicated to a body or to the organs of a -machine. With the disappearance of motion we -note the appearance of heat. Examples abound. -The tyre of a wheel is heated by the friction of the -road. Portions of steel are warmed by the impact -with stone, as in the old flint and steel. Two pieces -of ice were melted by Davy, who rubbed them one -against the other, the external temperature being -below zero. The boiling of a mass of water caused -by a drill was noticed by Rumford in 1790, during -the manufacture of bronze cannon. Metal, beaten on -an anvil, is heated. A leaden ball flattened against a -resisting obstacle shows increase of temperature carried -to the point of fusion. Finally, and symbolically, we -have the origin of fire in the fable of Prometheus, by -rubbing together the pieces of wood which the Hindoos -called <i>pramantha</i>. Correlation is constant between -the thermal and mechanical phenomena, a correlation -that becomes evident as soon as observers have ceased -to restrict themselves to the determination in isolation -of the one fact or the other. There is never any real -destruction of heat and motion in the true sense of the -word; what disappears in one form appears again in -another; just as if something indestructible were appearing -in a series of successive disguises. This -impression is translated into words when we speak<span class="pagenum" id="Page_81">[Pg 81]</span> -of the metamorphosis of mechanical into thermal -energy.</p> - -<p><i>The Mechanical Equivalent of Heat.</i>—The interpretation -assumes a remarkable character of precision, -which at once strikes the mind when physics applies -to these transformations the almost absolute accuracy -of its measurements. We then find that the rate of -exchange is invariable. Transformations of heat into -motion, and of motion into heat, take place according -to a rigorous numerical law, which brings into exact -correspondence the quantity of each. Mechanical -effect is estimated, as we have seen, by work, that is in -kilogrammetres. Heat is measured in calories, the -calorie being the quantity of heat necessary to raise -from 0°C to 1°C a kilogramme of water (Calorie) or -one gramme of water (calorie). It is found that -whatever may be the bodies and the phenomena -which serve as intermediaries for carrying out this -transformation, we must always expend 425 kilogrammetres -to create a Calorie, or expend 0·00234 -Calories to create a kilogrammetre. The number 425 -is the mechanical equivalent of the Calorie, or, as is -incorrectly stated, of the heat. It is this constant fact -which constitutes <i>the principle of the equivalence of heat -and of mechanical work</i>.</p> - - -<h4>§ 5. <span class="smcap">Chemical Energy.</span></h4> - -<p>We cannot yet actually measure chemical activity -directly, but we know that chemical action may give -rise to all other phenomenal modalities. It is their -most ordinary source, and it is to it that industries -appeal to obtain heat, electricity, and mechanical<span class="pagenum" id="Page_82">[Pg 82]</span> -action. In the steam engine, for instance, the work -that is received arises from the combustion of carbon -by the oxygen of the air. This gives rise to the heat -which vaporizes the water, produces the tension of the -steam, and ultimately produces the displacement of -the piston. The theory of the steam engine might be -reduced to these two propositions: chemical activity -gives rise to heat, and heat gives rise to motion; or to -use the language to which the reader by now will be -accustomed, chemical energy is transformed into -thermal energy, and that into mechanical energy. It -is a series of phases and of instantaneous changes, and -the exchange is always affected according to a fixed -rate.</p> - -<p><i>The Measurement of Chemical Energy.</i>—Our knowledge -of chemical energy is less advanced than that of -the energies of heat and sensible motion. We have -not yet reached the stage of numerical verifications. -We can only therefore affirm the equivalence of -chemical and thermal energies without the aid of -numerical constants, because we do not yet, in the -present state of science, know how to measure -chemical energy directly. Other known energies are -always the product of two factors: the mechanical -energy of position, or work, is measured by the -product of the force <i>f</i>, and the displacement <i>s</i>; work -= <i>fs</i>; the mechanical energy of motion, U = 1∕2<i>mv<sup>2</sup></i>, is -measured by the product of the mass into half the -square of the velocity. Thermal energy is measured -by the product of the temperature and the specific -heat; electric energy by the product of the quantity -of electricity (in coulombs) and of the electromotive -force (in volts). As for chemical energy, we guess -that it may be valued directly according to Berthollet’s<span class="pagenum" id="Page_83">[Pg 83]</span> -system, adopted by the Norwegian chemists, Guldberg -and Waage, by means of the product of the masses -and of a force, or co-efficient of affinity, which depends -on the nature of the substances which are brought together, -on the temperature, and on the other physical -circumstances of the reaction. On the other hand, -the researches of M. Berthelot enable us in many -cases to obtain an indirect valuation in terms of the -equivalent heat.</p> - -<p><i>Its Two Forms.</i>—It is interesting to note that -chemical energy may also be regarded from the two -states of <i>potential</i> and <i>kinetic energy</i>. The coal-oxygen -system, to burn in the furnace of the steam -engine, must be primed by preliminary work (local -ignition), just as the weight that is raised and left -motionless at a certain height requires a small -effort to be detached from its support. When this -condition is fulfilled, energy is at once manifest. -We must admit that it existed in the latent state, in -the state of <i>chemical potential energy</i>. Under the -impulse received, the carbon combines with the -oxygen and forms carbonic acid, C + 2O becomes -CO<sub>2</sub>; potential energy is changed into actual chemical -energy, and immediately afterwards into thermal -energy. We should have only a very incomplete and -fragmentary view of the reality of things if we were -to consider this phenomenon of combustion in isolation. -We must consider it in connection with what has -actually created the energy which it is about to -dissipate. This antecedent fact is the action of the -sun upon the green leaf. The carbon which burns in -the furnace of the machine comes from the mine in -which it was stored in the form of coal—that is to say, -of a product which was vegetable in its primitive form,<span class="pagenum" id="Page_84">[Pg 84]</span> -and which was formed at the expense of the carbonic -acid of the air. The plant had separated, at the -expense of the solar energy, the carbon from the -oxygen to which it was united in the carbonic acid of -the atmosphere. It had created the system C + 2O. -So that the solar energy produces the chemical potential -energy which was so long before it was utilized. -Combustion expends this energy in making carbonic -acid over again.</p> - -<p><i>Materialization of Energy.</i>—The fertility of the -idea of energy is therefore, as we see from all -these examples, due to the relations it establishes -between the natural phenomena of which it exhibits -the necessary relation, destroyed by the excessive -analysis of early science. It shows us that in the -world of phenomena there is nothing but transformations -of energy. And we regard these transformations -themselves as the circulation of a kind of -indestructible agent which passes from one form of -determination to another, as if it were simply putting -on a fresh disguise. If our intellect requires images -or symbols to embrace the facts and to grasp their -relation, it may introduce them here. It will materialize -energy, it will make of it a kind of imaginary being, -and confer upon it an objective reality. And for the -mind, as long as it does not become the dupe of the -phantom which it itself has created, this is an -eminently comprehensive artifice which enables us -to grasp readily the relations between phenomena -and their bond of affiliation.</p> - -<p>The world appears to us then, as we said at the -outset, constructed with singular symmetry. It offers -to us nothing but transformations of matter and -transformations of energy; these two kinds of meta<span class="pagenum" id="Page_85">[Pg 85]</span>morphoses -being governed by two laws equally -inevitable, the conservation of matter and the conservation -of energy. The first of these laws expresses -the fact that matter is indestructible, and passes -from one phenomenal determination to another at -a rate of equivalence measured by weight; the -second, that energy is indestructible, and that it -passes from one phenomenal determination to another -at a rate of equivalence fixed for each category by -the discoveries of the physicists.</p> - - -<h4>§ 6. <span class="smcap">Transformations of Energy.</span></h4> - -<p>The idea of energy has become the point of departure -of a science, <i>Energetics</i>, to the establishment of which -a large number of contemporary physicists, among -whom are Ostwald, Le Châtelier, etc., have devoted -their efforts. It is the study of phenomena, regarded -from the point of view of <i>energy</i>. I have said that it -claims to co-ordinate and to embrace all other sciences.</p> - -<p>The first object of energetics should be the consideration -of the different forms of energy at present -known, their definition and their measurement. This -is what we have just done in broad outline.</p> - -<p>In the second place, each form of energy must be -regarded with reference to the rest, so as to determine -if the transformation of this into that is directly -realizable, and by what means, and, finally, according -to what rate of equivalence. This new chapter is a -laborious task which would compel us to traverse the -whole field of physics.</p> - -<p>Of this long examination we need only concern -ourselves here with three or four results which will be<span class="pagenum" id="Page_86">[Pg 86]</span> -more particularly important in the case of applications -to living beings. They refer to mechanical energy, to -the relations of thermal energy and chemical energy, -to the complete rôle of thermal energy, and finally to -the extreme adaptability of electrical energy.</p> - -<p>1. <i>Transformation of Mechanical Energy.</i>—Mechanical -energy may change into every other form -of energy, and all others can change into it, with but -one exception, that of chemical energy. Mechanical -effort does not produce chemical combination. What -we know of the part played by pressure in the reactions -of dissociation seems at first to contradict -this assertion. But this is only in appearance. Pressure -intervenes in these operations only as <i>preliminary -work</i> or <i>priming</i>, the purpose of which is to bring the -bodies into contact in the exact state in which they -must be for the chemical affinities to be able to enter -into play.</p> - -<p>2. <i>Transformation of Thermal Energy; Priming.</i>—Thermal -(or luminous) energy does not change -directly into chemical energy. In fact, heat and light -favour and even determine a large number of chemical -reactions; but if we go down to the foundation of -things we are not long before we feel assured that -heat and light only serve in some measure for -<i>priming</i> for the phenomenon, for preparing the -chemical action, for bringing the body into the -physical state (liquid, steam) or to the degree of -temperature (400° C. for instance, for the combination -of oxygen and hydrogen) which are the preliminary -indispensable conditions for the entry upon the scene -of chemical affinities.</p> - -<p>On the contrary, chemical energy may really be -transformed into thermal energy. We have an<span class="pagenum" id="Page_87">[Pg 87]</span> -instance of this in the reactions which take place -without the aid of external energy; and again, in -those very numerous cases which, such as the combustion -of hydrogen and carbon, or the decomposition -of explosives, the reactions continue when once primed. -I may make a further observation apropos of thermal -and photic energy. These are not two really and -essentially distinct forms, as was thought in the early -days of physics. When we consider things objectively, -there is absolutely no light without heat; light and -heat are one and the same agent. According as it is -at this or that degree of its scale of magnitude, it -makes a stronger impression on the skin (sensation of -heat) or on the retina (sensation of light) of man and -animals. The difference may be put down to the -diversity of the work and not to that of the agent. -The kinetic theory shows us that the agent is -qualitatively identical. The words heat and light -only express the chance of the meeting of the radiant -agent with a skin and a retina. At the lowest degree -of activity this agent exerts no action on the terminations -of the thermal cutaneous nerves, nor on the -optic nerve-terminations. As this degree is raised -the former of these nerves are affected (cold, heat) and -are so to the exclusion of the nerves of vision. Then -they are both affected (sensation of heat and light), -and finally, beyond that, sight alone is affected. The -transformation of one energy into the other is therefore -here reduced to the possibility of increasing or -decreasing the intensity of the action of this common -agent in the exact proportions suitable for passing -from one of the conditions to the other; and this is -easy when it is a question of going up the scale in the -case of light, and, on the contrary, it is not realizable<span class="pagenum" id="Page_88">[Pg 88]</span> -directly, that is to say without external assistance, -when it is a question of going down the scale again, in -the case of heat.</p> - -<p>3. <i>Heat a Degraded Form of Energy.</i>—We have -seen that thermal energy is not directly transformed -into chemical energy. There is yet another restriction -in the case of this thermal energy if we study the laws -which govern the circulation and the transformations -of thermal energy; and the most important comes from -the impossibility of transporting it from a body at -a lower temperature to a body at a higher temperature. -On the whole, and because of these restrictions, -thermal energy is an imperfect variety of universal -energy, or, as the English physicists call it, a degraded -form.</p> - -<p>4. <i>Simple Transformations of Electrical Energy. Its -Intermediary Rôle.</i>—On the other hand, electrical energy -represents a perfected and infinitely advantageous form -of this same universal energy, and this explains the vast -development of its industrial applications within less -than a century. It is not that it is better known than -the others in its nature and in the secret of its action. -On the contrary, there is more dispute than ever as to -its nature. To some, electricity, which is transported -and propagated with the speed of light, is a real flux -of the ether as was taught by Father Secchi, who -compared it to a current of water in a pipe. It would -do its work, just as the water of the mill does its -work by flowing over a wheel or through a turbine. -Electricity, like water in this case, would not be -an energy in itself, but a means of transporting -energy.</p> - -<p>To others, such as Clausius, Hertz, and Maxwell, it -is not so; the electric current is not a transport of<span class="pagenum" id="Page_89">[Pg 89]</span> -energy. It is a state of the ether of a peculiar, -specific kind, periodically produced (electric oscillation), -and propagated with a speed of the order of -that of light.</p> - -<p>However that may be, what constitutes the essential -peculiarity of electrical energy, and what causes its -value, is that it is an incomparable agent of transformation. -Every known form of energy may be -converted into it, and inversely, electrical energy may -be changed with the utmost facility into all other -energies. This extreme adaptability assigns to it -the part of an intermediary between the other less -tractable agents. Mechanical energy, for instance, -lends itself with difficulty to the production of light, -that is to say, to a metamorphosis into photic energy -(a variety of thermal energy). A fall of water cannot -be directly utilized for lighting purposes. The -mechanical work of this fall, which cannot be -exploited in its present form, serves to set in -motion in industrial lighting the installations, the -electric machines, and the dynamos which feed the -incandescent lamps. Mechanical work is changed -into electrical energy, and it, in its turn, into thermal -or photic energy. Electricity has here played the part -of a useful intermediary.</p> - -<p>The last part of energetics must be consecrated to -the study of the general principles of this science. -These principles are two in number, the principle of -the <i>conservation of energy</i>, or Mayer’s principle, and -the principle of the transformation of energy, or -Carnot’s principle. The doctrine of energy thus -reduces to two fundamental laws the multitude of -laws, often known as “general,” to which natural -science is subject.</p> - -<p><span class="pagenum" id="Page_90">[Pg 90]</span></p> - - -<h4>§ 7. <span class="smcap">The Principle of the Conservation -of Energy.</span></h4> - -<p>In all that precedes, the principle of conservation has -intervened at every step. In fact, the very idea of -energy is connected with the existence of this principle. -We first discover the idea in the work of the philosophical -mathematicians who established the foundations -of mechanics:—Newton, Leibniz, d’Alembert, -and Helmholtz; or of inductive physicists such as -Lord Kelvin. Its experimental proof, sketched by -Marc Seguin and R. Mayer, is due to Colding and -Joule.</p> - -<p><i>It is Independent of the Kinetic Theory.</i>—Mayer’s -law states that energy is indestructible; that all -phenomenality is nothing but a transformation of -energy from one form to another, and that this -transformation takes place either at equal values, -or rather, at a certain rate of equivalence. This is -what takes place when thermal energy is transformed -into mechanical energy (equivalent 425). This rate -of equivalence is fixed by the researches of physicists -for each category of energy.</p> - -<p>It will be noticed that this law and this theory of -energy, which is always presented by authors of -elementary books as a consequence of the kinetic -theory, is quite independent of it. In the preceding -lines we have not even mentioned its name. We -have not assumed that all phenomena are movements -or transformations of movements, whether sensible or -vibratory; we have not affirmed that what was -passing from one phenomenal determination to -another was the <i>vis viva</i> of the motion, as is the case<span class="pagenum" id="Page_91">[Pg 91]</span> -in the impact of elastic bodies. No doubt the kinetic -theory affords us a very striking image of these truths -which are independent of it; but it may be false: and -the theory of energy which assumes the minimum of -possible hypotheses would yet be true.</p> - -<p><i>It contains a great many other Principles.</i>—The -principle of the conservation of energy contains -a large number of the most general principles of -science. It may be shown without much difficulty -that, for example, it contains the principle of the -inertia of matter, laid down by Galileo and Descartes; -that of the equality of action and reaction, due to -Newton; and even that of the conservation of matter, -or rather of mass, due to Lavoisier. And finally, it -contains the experimental law of equivalence connected -with the name of the English physicist Joule, -from which may be derived the Law of Hess and the -principle of the initial and final states which we owe -to Berthelot.</p> - -<p><i>It involves the Law of Equivalence.</i>—Here we may -be content with noticing that the law of the conservation -of energy involves the existence of relations of -equivalence between the different varieties. A certain -quantity of a given energy, measured, as we have -seen, by the product of two factors, is equivalent to a -certain fixed quantity of quite a different form of -energy into which it may be converted. The laws -which govern energetic transformations therefore contain, -from both the qualitative and the quantitative -points of view, all the connections of the phenomena -of the universe. To study these laws in their detail is -the task that physics must take upon itself.</p> - -<p>The conversion one into the other of the different -forms of energy by means of equivalents is only a<span class="pagenum" id="Page_92">[Pg 92]</span> -possibility. It is subject, in fact, to all sorts of -restrictions, of which the most important are due to -the second principle.</p> - - -<h4>§ 8. <span class="smcap">Carnot’s Principle. Its Generality.</span></h4> - -<p>The second fundamental principle is that of the -transformations of equilibrium, or of the conditions -of reversibility, or again, Carnot’s principle. This -principle, which first assumed a concrete form in -thermodynamics, has been very widely extended. It -has reached a degree of generality such that contemporary -theoretical physicists such as Lord Kelvin, Le -Châtelier, etc., consider it the universal law of -physical, mechanical, and chemical equilibrium.</p> - -<p>Carnot’s principle contains, as was shown by G. -Robin, d’Alembert’s principle of virtual velocities, -and according to physicists of to-day, as we have just -remarked, it contains the laws peculiar to physico-chemical -equilibrium. The application of this principle -gives us the differential equations from which -are derived numerical relations between the different -energies, or the different modalities of universal -energy.</p> - -<p><i>Its Character.</i>—It is very remarkable that we cannot -give a general enunciation of this principle which -by its revealing power has changed the face of -physics. This is because it is less a law, properly so -called, than a method or manner of interpreting the -relations of the different forms of energy, and particularly -the relations of heat and mechanical energy.</p> - -<p><i>Conversion of Work into Heat and Vice-versâ.</i>—The -conversion of work into heat is accomplished without -difficulty. For example, the hammering of a piece of<span class="pagenum" id="Page_93">[Pg 93]</span> -iron on an anvil may bring it to a red heat. A shell -which passes through an armour plate is heated, and -melts and volatilizes the metal all round the hole it -has made. By utilizing mechanical action under the -form of friction all energy can be converted into heat.</p> - -<p>The inverse transformation of heat into work, on -the contrary, cannot be complete. The best motor -that we can think of, and <i>à fortiori</i> the best we can -realize, can only transform a third or a fourth of the -heat with which it is supplied.</p> - -<p>This is an extremely important fact. It is of incalculable -importance to natural philosophy, and may -be ranked among the greatest discoveries.</p> - -<p><i>Higher and Degraded Forms of Energy.</i>—Of these -we may give an account by distinguishing among the -forms of universal energy <i>higher forms</i>, and <i>lower</i> or -<i>degraded forms</i>. Here we have the principle of the -<i>degradation of energy</i> on its trial, and it may be -regarded as a particular aspect of the second principle -of energetics, or Carnot’s principle. Mechanical -energy is a higher form. Thermal energy is a lower -form, a degraded form, and one which has degrees in -its degradation. Higher energy, in general, may be -completely converted into lower energy; for example, -work into heat: the slope is easy to descend, but it is -difficult to retrace our steps; lower energy can be -only partially transformed into higher energy, and the -fraction thus utilizable depends upon certain conditions -on which Carnot’s principle has thrown considerable -light.</p> - -<p>Thus, although in theory the thermal energy of a -body may have its equivalent in mechanical energy, -the complete transformation is only realizable from -the latter to the former, and not from the former to<span class="pagenum" id="Page_94">[Pg 94]</span> -the latter. This is due to a condition of thermal -energy which is called <i>temperature</i>. The same -quantity of thermal energy, of heat, may be stored -in the same thermal body at different temperatures. -If this quantity of thermal energy is in a very hot -body we can utilize a large portion of it; if it is in a -relatively cold body we can only convert a small -portion of it into mechanical work. Thus the value -of energy,—<i>i.e.</i>, its capacity of being converted into -a higher and more useful form,—depends on temperature.</p> - -<p><i>The Capacity of Conversion depends on Temperature.</i>—The -conversion of heat into work assumes two -bodies of different temperatures, the one warm and -the other cold; a boiler and a condenser. Every -thermal machine conveys a certain amount of heat -from the boiler to the condenser, and what is not thus -carried is changed into work. This residue is only a -small fraction, a quarter, or at most a third of the -heat employed, and that, too, in the theoretically -perfect machine, in the ideal machine.</p> - -<p>This output, this utilizable fraction depends on the -fall of temperature from the higher to the lower level, -just as the work of a turbine depends on the height -of the waterfall which passes through it. But it also -depends on the conditions of this fall, on the -accessory losses from radiation and conduction. -However, Carnot has shown that the output is the -same, and a maximum for the same fall of temperature, -whatever be the working agent (steam, hot air, etc.), -and whatever be the machine—provided that this -agent, this substance which works is not exposed to -accessory losses, that it is never in contact with a -body having temperature different to its own—or<span class="pagenum" id="Page_95">[Pg 95]</span> -again, that it is connected only with bodies impermeable -to heat.</p> - -<p>This is Carnot’s principle in one of its concrete -forms.</p> - -<p>A machine which realizes this condition, that the -agent (steam, alcohol, ether) is in relation, at all -phases of its function, with bodies which can neither -take heat from it nor give heat to it, is a <i>reversible -machine</i>. Such a machine is perfect. The fraction -of heat that it transforms into motion is constant; it -is a maximum; it is independent of the motor, of its -organs, of the agent: it accurately expresses the -transformability of the heat agent into a mechanical -agent under the given conditions.</p> - -<p><i>The Degradation and Restoration of Energy.</i>—The -fraction not utilized, that which is carried to the -condenser at a lower temperature, is <i>degraded</i>. It -can only be used by a new agent, in a new machine -in which the boiler has exactly the same temperature -as the condenser in the first machine, and the new -condenser has a lower temperature, and so on. The -proportion of utilizable energy thus goes on diminishing. -Its utilization requires conditions more and -more difficult to realize. The thermal energy loses its -potential and its value, and is further and further degraded -as its temperature approaches that of the -surrounding medium.</p> - -<p>The degraded energy, theoretically, has kept its -equivalent value but, practically, it is incapable of -conversion. However, it is shown in physics that it -can be raised and re-established at its initial level. -But for that purpose another energy must be utilized -and degraded for its benefit.</p> - -<p><i>The End of the Universe.</i>—What we have just<span class="pagenum" id="Page_96">[Pg 96]</span> -seen with respect to heat and motion is to some -degree true of all other forms of energy, as Lord -Kelvin has shown. The principle of the degradation -of energy is very general. Every manifestation of -nature is an energetic transformation. In each of -these transformations there is a degradation of energy—<i>i.e.</i>, -a certain fraction is lowered and becomes less -easily transformable. So that the energy of the -universe is more and more degraded; the higher -forms are lowered to the thermal form, the latter -increasing at temperatures which become more and -more uniform. The end of the universe, from this -point of view, would then be unity of (thermal) energy -in uniformity of temperature.</p> - -<p><i>Importance of the Idea of Energy in Physiology.</i>—I -have said that the application of Carnot’s principle -furnished numerical relations between the different -energetic transformations.</p> - -<p>The science of living beings has not yet reached -that point of development at which it is possible for -us to obtain its numerical relations. However, the -consideration of energy and the principle of conservation -has altered the outlook of physiology on many -questions which are of the highest importance.</p> - -<p>The determination of the sources from which plants -and animals draw their vital energies; the mediate -transformation of chemical energy into animal heat in -nutrition, or into motion in muscular contraction; the -chemical evolution of foods; the study of soluble -ferments—all these questions are of considerable -importance when we wish to understand the -mechanisms of life. They are therefore departments -of physiological energetics in which great -advances have already been made.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_97">[Pg 97]</span></p> - -<h3 class="nobreak" id="CHAPTER_II_2">CHAPTER II.<br /> - -<small>ENERGY IN BIOLOGY.</small></h3></div> - - -<p class="prel">§ 1. Energy in Living Beings.—§ 2. The First Law of Biological -Energetics:—All Vital Phenomena are Energetic Transformations.—§ 3. Second -Law:—The Origin of Vital -Energy is in Chemical Energy. Functional Activity and -Destruction.—§ 4. Third Law:—The Final Form of -Energetic Transformation in the Animal is Thermal -Energy. Heat is an Excretum.</p> - - -<p>The theory of energy was thought of and utilized in -physiology before it was introduced into physics, in -which it has exercised such an extraordinary influence. -Robert Mayer was a physicist and a doctor. Helmholtz -was equally at home in physiology and in physics. -From the outset both had seen in this new idea a -powerful instrument of physiological research. The -volume in which Robert Mayer expounded, in 1845, -his remarkable views on organic movement in relation -to nutrition, and Helmholtz’ commentary leave us in -no doubt in this respect. The essay on the mechanical -equivalent of heat, of a more particularly physical -character, is six years later than the earlier work.</p> - -<p><i>The Relations between Energetics and Biology.</i>—The -theory of energy is therefore only returning to -its cradle; and to that cradle it returns with all the -sanction of physical proof, as the most general theory<span class="pagenum" id="Page_98">[Pg 98]</span> -ever proposed in natural philosophy, and the theory -least encumbered with hypotheses. It reduces all -particular laws to two fundamental principles—that -of the conservation of energy, which contains the -principles of Galileo and Descartes, of Newton, of -Lavoisier, Joule’s law, Hess’s law, and Berthelot’s -principle of the initial and final states; and also -Carnot’s principle, from which are deduced the laws -of physico-chemical and chemical equilibrium. These -two principles therefore sum up the whole of natural -science. They express the necessary relation of all -the phenomena of the universe, their uninterrupted -gentic connection, and their continuity.</p> - -<p><i>A priori</i> there would be little likelihood that a -doctrine, so universal and so thoroughly verified in -the physical world, could be restricted, and thus -be useless to the living world. Such a supposition -would be contrary to the scientific method, which -always tends to the generalization and the explanation -of elementary laws. The human mind has always -proceeded thus: it has applied to the unknown -order of living phenomena the most general laws of -contemporary physics.</p> - -<p>This application has been found legitimate, and has -been justified by experiment whenever it has been a -question of the laws or of the really fundamental or -elementary conditions of phenomena. It has, on the -other hand, however, been unfortunate when it has -stopped short of secondary characteristics. When we -now concede the subjection of living beings to these -general laws of energetics, we are following a -traditional method. There is no doubt that this -application is legitimate, and that experiment will -justify it <i>a posteriori</i>.</p> - -<p><span class="pagenum" id="Page_99">[Pg 99]</span></p> - -<p>I will therefore grant, as a provisional <i>postulate</i>, -the consequences of which will have to be ultimately -justified, that the living and inanimate world alike -show us nothing but <i>transformations of matter</i> and -<i>transformations of energy</i>. The word phenomenon -will have no other signification, whatever be the -circumstances under which the phenomenon occurs. -The varied manifestations which translate the activity -of living beings thus correspond to transformations of -energy, to conversions of one form into another, in -conformity with the rules of equivalence laid down by -the physicists. This conception may be formulated -in the following manner:—<i>The phenomena of life have -the same claim to be energetic metamorphoses as the -other phenomena of nature</i>.</p> - -<p>This postulate is the foundation of biological -energetics. It may be useful to give some explanation -relative to the signification, the origin, and -the scope of this statement.</p> - -<p>Biological energetics is nothing but general physiology -reduced to the principles that are common to all -the physical sciences. Robert Mayer and Helmholtz -gave the best description of this science, and laid -down its limits by defining it as “the study of the -phenomena of life regarded from the point of view -of energy.”</p> - - -<h4>§ 1. <span class="smcap">Energy at play in Living Beings. -Common or Physical Energies. Vital -Energies.</span></h4> - - -<p>Our first object will be to define and to enumerate the -energies at play in living beings; to determine their -more or less easy transformations from one to another,<span class="pagenum" id="Page_100">[Pg 100]</span> -to bring to light the general laws which govern those -transformations, and finally to apply them to the -detailed study of phenomena. This programme may -be divided into four parts.</p> - -<p>In the physical world the specific forms of energy -are not numerous. When we have mentioned -mechanical, chemical, radiant (thermal and photic) -energies, electrical energy, with which is blended -magnetic energy, we have exhausted the catalogue of -natural agents.</p> - -<p>But is this list for ever closed? Are vital energies -comprised in this list? These are the first questions -which we must ask ourselves.</p> - -<p>The iatro-mechanical school, on <i>a priori</i> grounds -give an affirmative answer. No doubt there are in the -living organism many manifestations which are pure -physical manifestations of known energies, mechanical, -chemical, thermal, etc. But are all the manifestations -of the living being of this order? Are they all, henceforth, -reducible to the categories and varieties of energy -which are investigated in physics? This is the claim -of the mechanical school. But the claim is rash. Our -fundamental postulate affirms, in principle, that universal -energy is manifested in living beings; but, as a -matter of fact, there is no reason for the assertion that -it does not assume particular forms, according to the -circumstances peculiar to the conditions under which -they are produced.</p> - -<p>These <i>special forms of energy</i> manifested in the conditions -suitable to living beings would swell the list -drawn up by the physicists. And it would not be the -first instance of an extension of this kind. The -history of science records many remarkable cases. -Scarcely a century has passed since we first heard of<span class="pagenum" id="Page_101">[Pg 101]</span> -electrical energy. This discovery in the world of -energy, which took place, so to speak, before our -very eyes, of an agent which plays so large a part -in nature, clearly leaves the door open to other -surprises.</p> - -<p>We shall therefore concede that there may be -other forms of energy at work in living beings than -those we already know in the physical world. This -reservation would enable us to discover at once the -essential characteristics by which vital phenomena -are henceforth reduced to universal physics, and -the purely formal differences still distinguishing -them.</p> - -<p>If there are really special energies in living beings, -our monistic postulate leads us to assert that these -energies are homogeneous with the others, and that -they do not differ from them more than they differ -among themselves. It is probable that some day -they will be discovered external to living bodies, if -the material conditions (which it is always possible to -imagine) are realized externally to them. And if we -must admit that the peculiarity of the medium is -such that these forms must remain indefinitely -peculiar to living beings, we may assert with every -confidence that these special energies do not obey -special laws. They are subject to the two fundamental -principles of Robert Mayer and Carnot. -They are exchanged according to fixed laws with -the other physical forms of energies at present -known.</p> - -<p>To sum up, then, we must establish three categories -in the forms of energy which express the phenomena -of vitality.</p> - -<p>In the first place, most of these energies are those<span class="pagenum" id="Page_102">[Pg 102]</span> -which have already been studied and recognized in -general physics. They are the same energies: -chemical, thermal, mechanical, with their characteristics -of mutability, their lists of equivalents, -and their actual and potential stales.</p> - -<p>In the second place, it may happen, and it probably -will happen, as it happened in the last century -in the case of electricity, that some new form of -energy will be discovered belonging to the universal -order as to the living order. This will be a conquest -of general physics as well as of biology.</p> - -<p>And finally we may rigorously and provisionally -admit a last category of <i>vital energies properly so -called</i>.</p> - -<p>It is difficult to give much precision to the idea of -<i>vital energies properly so called</i>.</p> - -<p>It will be easier to measure them by means of -equivalents than to indicate their nature. Besides, -this is the ordinary rule in the case of physical agents. -We can measure them, although we know not what -they are.</p> - -<p><i>Characteristics of Vital Energies.</i>—We see why we -cannot exhibit with precision, <i>a priori</i>, the nature of -vital energies. In the first place, they are expressed -by what takes place in the tissues in activity, and -this cannot at present be identified with the known -types of physical, chemical, and mechanical phenomena. -This is a first, intrinsic reason for not being -able to distinguish them readily, since what takes -place is not distinguished by the phenomenal appearances -to which we are accustomed.</p> - -<p>There is a second, intrinsic reason. These vital -phenomena are intermediary, as we shall see, between -manifestations of known energies. They lie between<span class="pagenum" id="Page_103">[Pg 103]</span> -a chemical phenomenon which always precedes them, -and a thermal phenomenon which always follows -them. They are lost sight of, as it were, between -manifestations which strike our attention. Generally -speaking, intermediary energies often escape us -even in physics. Only the extreme manifestations -are clearly seen. In the presence of the organism -we are, as it were, in electric lighting works which -are run by a fall of water, and at first we only -see the mechanical energy of the falling water, -of the turbine and dynamo at work, and the -photic energy of the lamps which give the light. -Electrical energy, an intermediary, which has only -a transient existence, does not impose itself on our -attention.</p> - -<p>And so <i>vital energies</i> for this twofold reason, intrinsic -and extrinsic, are not readily apparent. To -reveal them, the careful analysis of the physiologists -is required. They are acts, in most cases silent and -invisible, which we should scarcely recognize but by -their effects, after they have terminated in familiar, -phenomenal forms. This is, for example, what goes -on in the muscle in process of shortening, in the nerve -carrying the nervous influx, in the secreting gland. -And this is what constitutes the different forms of -energy which we call <i>vital properties</i>. M. Chauveau -and M. Laulanié use the phrase <i>physiological work</i> -to distinguish them. <i>Vital energy</i> would be preferable. -It better expresses the analogy of this special -form with the other forms of universal energy; it -helps us better to understand that we must henceforth -consider it as exchangeable by means of -equivalents with the energies of the physical world -just as they are exchangeable one with another.</p> - -<p><span class="pagenum" id="Page_104">[Pg 104]</span></p> - - -<h4>§ 2. <span class="smcap">First Law of Biological Energetics.</span></h4> - - -<p>It is easy to understand, after these remarks, the -significance and the scope of this assertion which -contains the first principle of biological energetics—namely, -that the phenomena of life have the same -claim to be called energetic metamorphoses as the -other phenomena of nature.</p> - -<p><i>Irreversibility of Vital Energies.</i>—However, there -is one characteristic of vital energies which deserves -the closest attention. Their transformations have a -direction which is in some measure inevitable. They -descend a slope which they never re-ascend. They -appear to be irreversible. Ostwald has rightly insisted -on this fundamental characteristic, which no -doubt is not that of all the phenomena of the living -being without exception, but which is certainly that of -the most essential phenomena. There are reversible -phenomena in organisms; there are energetic transformations -which may take place from one form of -energy to another, or <i>vice versâ</i>. But the most -characteristic phenomena of vitality do not act in -this way. We shall presently see that most functional -physiological acts begin with chemical and end with -thermal action. The series of energetic transformations -takes place in an inevitable direction, from -chemical to thermal energy. The order of succession -of ordinary energies is thus determined in the machine -of the organism, and therefore by the conditions of -the machine. The order of transformation of vital -energies is still more rigorously regulated, and the -phenomena of life evolve from childhood to ripened -years, and thence to old age, without a possible -return.</p> - -<p><span class="pagenum" id="Page_105">[Pg 105]</span></p> - -<p>The laws of biological energetics are three in number. -First of all, there is the fundamental principle -which we have just developed, and which is, so to -speak, laid down <i>a priori</i>; and there are two other -principles, those established by experiment and -summing-up, as it were, the multitude of known -physiological effects. Of these two experimental -laws, one refers to the <i>origin</i> and the other to the -<i>termination of the energies developed in living beings</i>.</p> - - -<h4>§ 3. <span class="smcap">Second Law of Biological Energetics.</span></h4> - - -<p><i>The Origin of Vital Energy.</i>—Vital energies have -their origin in one of the <i>external or common energies</i>—not -in any one we choose, as might be supposed, -but in one only: chemical energy. The third principle -will show us that they terminate in another energy or -a few others, also completely fixed.</p> - -<p>It follows that the phenomena of life must appear -to us to be a circulation of energy which, starting from -one fixed point in the physical world, returns to that -world by a few points, also fixed, after a transient -passage through the animal organism.</p> - -<p>Or more precisely, it is a transposition from the -realm of matter into the world of energy, of the idea -of the <i>vital vortex</i> of Cuvier and the biologists. -They defined life by its most constant property—nutrition. -Nutrition was exactly this current of -matter which the organism obtains from without by -alimentation, and which it throws out again by excretion; -and the even momentary interruption of -which, if complete, would be the signal of death. -The cycle of energy is the exact counterpart of -this cycle of matter.</p> - -<p><span class="pagenum" id="Page_106">[Pg 106]</span></p> - -<p>The second truth taught us by general physiology, -a truth which physiology learned from experiment, is -enunciated as follows:—<i>The maintenance of life consumes -none of its energy. It borrows from the external -world all the energy which it expends, and borrows it in -the form of potential chemical energy.</i> This is a translation -into the language of energetics of the results -acquired in animal physiology during the last fifty years. -No comment is needed to exhibit the importance of -such a truth. It reveals the origin of animal activity. -It reveals the source from which proceeds that energy -which at some moment of its transformations in the -animal organism will be a <i>vital energy</i>.</p> - -<p>The <i>primum movens</i> of vital activity is, therefore, -according to this law, the chemical energy stored up -in the immediate principles of the organism.</p> - -<p>Let us try to follow, for a moment, this energy -through the organism and to specify the circumstances -of its transformations.</p> - -<p><i>Organic Functional Activity, and the Destruction of -Reserve-stuff.</i>—Let us suppose then, for this purpose, -that our attention is directed to a given limited part -of this organism, to a certain tissue. Let us seize -it, so to speak, by observation at a given moment, -and let us make an examination of the functional -activity starting from this conventional moment. -This functional activity, like all other vital phenomena, -will be the result, as we have just explained, of -a transformation of the potential chemical energy -contained in the materials held in reserve in the -tissue. This is our first perceptible fact. This -energy, when disengaged, will furnish to the vital -action the means by which it may be prolonged.</p> - -<p>There is, then, a <i>functional destruction</i>. There is, at<span class="pagenum" id="Page_107">[Pg 107]</span> -the beginning of the functional process, and by a -necessary effect of that very process, a liberation of -chemical energy; and that can only take place by a -decomposition of the immediate principles of the -tissue, or, as we may say, by a destruction of organic -material. Claude Bernard insisted on this consideration, -that the vital function is accompanied by a -destruction of organic material. “When a movement -is produced, when a muscle is contracted, when -volition and sensibility are manifested, when thought -is exercised, when a gland secretes, then the substance -of the muscles, of the nerves, of the brain, of the -glandular tissue, is disorganized, is destroyed, and is -consumed.” Energetics enables us to grasp the -deeply-seated reason of this coincidence between -chemical destruction and the functional activity, the -existence of which Claude Bernard intuitively suspected. -A portion of organic material is decomposed, -is chemically simplified, becomes less complex, and -loses in this kind of descent the chemical energy -which it contained in its potential state. It is this -energy which becomes the very texture of the vital -phenomenon.</p> - -<p>It is clear that the reserve of energy thus expended -must be replaced, because the organism remains in -equilibrium. Alimentation provides for this.</p> - -<p>How does it provide for it? This is a question -which deserves detailed examination. We cannot -incidentally treat it in full; we can only indicate its -main features.</p> - -<p><i>How the supply of Reserve Stuff is kept up.</i>—We -know that food does not directly replace the reserve -of energy consumed by the functional activity. It is -not its potential chemical energy which replaces,<span class="pagenum" id="Page_108">[Pg 108]</span> -purely and simply, the energy brought into play, -consumed, or, better still, transformed in the active -organ, or tissue. Food as it is introduced, inert food, -does not, in fact, take up its place <i>as it is</i>, without -undergoing changes in that organ and that tissue, in -order to restore the <i>status quo ante</i>.</p> - -<p>Before building up the tissue it will have undergone -various modifications in the digestive apparatus. It -will have also undergone changes in the circulatory -apparatus, in the liver, and in the very organ we are -considering. It is after all these changes that assimilation -takes place. It will find its place and will have -then passed into the state of <i>reserve</i>.</p> - -<p>The food digested, modified, and finally incorporated -as an integral part in the tissue in which it will be expended, -is therefore in a new state, differing more or -less from its state when it was ingested. It is a part -of the living tissue in the state of constitutive reserve. -Its potential chemical energy is not the same as that -of the food introduced. It may differ from it very -remarkably in consequence of sudden alterations.</p> - -<p>We do not know for certain at the expense of what -category of foods this or that given organ builds up -its reserve stuff. There is a belief, for instance, -according to M. Chauveau, that the muscle does its -work at the expense of the reserve of glycogen which -it contains. The potential chemical energy of this -substance would be a source of muscular mechanical -energy. But we do not know exactly at the expense -of what foods, albumenoids, fats, or carbohydrates -the muscle builds up the reserve of <i>glycogen</i> expended -during its contraction. It is probable that it builds it -up at the expense of each of the three categories after -the various more or less simple alterations undergone<span class="pagenum" id="Page_109">[Pg 109]</span> -by the materials in the digestive tube, the blood, the -liver, or other organs.</p> - -<p>This building up of reserve stuff, the complement -and counterpart of <i>functional destruction</i>, is not chemical -synthesis. It is, on the contrary, generally, and -on the whole, a simplification of the food that has -been introduced. This is true, at least as far as the -muscle is concerned. However, to this operation, -Claude Bernard has given the name of <i>organizing -synthesis</i>, but the phrase is not a happy one. But -in no case was the eminent physiologist deceived -as to the character of the operation. “The organizing -synthesis,” says he, “remains internal, silent, -hidden in its phenomenal expression, gathering -together noiselessly the materials which will be -expended.”</p> - -<p>These considerations enable us to understand the -existence of the two great categories into which the -eminent physiologist divides the phenomena of animal -life: the phenomena of the <i>destruction of reserve-stuff</i> -corresponding to <i>functional facts</i>—that is to say -expenditures of energy; and the <i>plastic phenomena</i> of -the <i>building-up of reserves</i> of organic regeneration, corresponding -to <i>functional repose</i>—<i>i.e.</i>, to the supply of -food to the tissues.</p> - -<p><i>Distinction between Active Protoplasm and Reserve-stuff.</i>—If -it is not exactly in these terms that Claude -Bernard formulated this fruitful idea, it is at any -rate in this way that it is to be interpreted. This -can be done by giving it a little more precision. -We apply more rigorously than that great physiologist -the distinction drawn by himself between <i>really -active and living protoplasm</i> and the <i>reserve-stuff</i> -which it prepares. To the latter is restricted the<span class="pagenum" id="Page_110">[Pg 110]</span> -destruction by the functional activity and the building -up by repose.</p> - -<p>The classification of Claude Bernard is strictly true -for reserve-stuff. It is easy to criticize the wavering -and, as it were, dimly groping expressions in -which the celebrated physiologist has shrouded his -ideas. The old adage will excuse him: <i>Obscuritate -rerum verba obscurantur</i>. In the depths of his ignorance -he had a flash of genius; perhaps he did not find -the definitive and, as it were, clearly-cut formula defining -what was in his mind. But, in this respect, he -has left his successors an easy task.</p> - -<p><i>The Law of Functional Assimilation.</i>—The progress -of physiological knowledge compels us therefore to -distinguish in the constitution of anatomical elements -two parts—the materials of <i>reserve-stuff</i> and the <i>really -active</i> and <i>living protoplasm</i>. We have just seen how -the reserve-stuff behaves, alternately destroyed by -functional activity, and built up afterwards by the -ingestion of food, followed by the operations of digestion, -elaboration, and assimilation. It remains to -ask how this really living and protoplasmic matter -behaves. Does it follow the same law? Is it destroyed -during the functional activity, and is it afterwards -replaced? As to this we can express no -opinion. M. le Dantec fills a gap in our knowledge, -in this respect, by an hypothesis. He assumes that -this essentially active matter grows during functional -activity, and is destroyed during repose. This is what -he calls the <i>law of functional assimilation</i>. The -protoplasm would therefore behave in an exactly -contrary manner to the reserve-stuff. It will be its -counterpart. But this is only an hypothesis which, -in the present state of our knowledge, cannot be<span class="pagenum" id="Page_111">[Pg 111]</span> -verified by experiment We are at liberty to -assert either that the protoplasm increases by -functional activity or that it is destroyed. Neither -the arguments nor the objections pro or con have any -decisive value. The facts alleged on either side are -capable of too many interpretations.<a id="FNanchor_10" href="#Footnote_10" class="fnanchor">[10]</a></p> - -<p>The only favourable argument (not demonstrative) -is furnished by energetics. It is this. The <i>re-building -of the protoplasm</i> is not like the <i>organisation of reserve-stuff</i>, -a slightly complicated or even simplified phenomenon, -as happens in the case of the reserve of -muscular glycogen. The glycogen, in fact, is built up -at the expense of foods chemically more complex. -It is, on the contrary, a clearly synthetic phenomenon, -certainly of chemical complexity, since it ends -in building up the active protoplasm which is, in some -measure, of the highest scale of complexity. Its formation -at the expense of the simplest alimentary -materials requires, therefore, an appreciable quantity -of energy.</p> -<p><span class="pagenum" id="Page_112">[Pg 112]</span></p> -<p>The assimilation which organizes the active protoplasm -therefore requires energy for its realization. -Now, at the moment of functional activity, and by a -necessary consequence thereof, the chemical destruction -or simplification of the substance of reserve takes -place. Here is something that meets the case, and -we may note the coincidence. It does not mean that -the disposable energy is really used to increase the -protoplasm, nor that the protoplasm itself is thereby -increased. It merely signifies that the wherewithal -exists to provide for that increase if it takes place.</p> - -<p>It is therefore <i>possible</i> that the active protoplasm -follows the law of functional assimilation; but it is -<i>certain</i> that the reserve-stuff follows the law laid down -by Claude Bernard.</p> - -<p>All these considerations definitely result in the -confirmation of this second law of general physiology, -according to which all vital energies are borrowed -from the potential chemical energy of the reserve-stuff -of alimentary origin.</p> - - -<h4>§ 4. <span class="smcap">The Third Law of Biological Energetics.</span></h4> - - -<p>The third law of biological energetics is also drawn -from experiment. It relates no longer to the point of -departure of the cycle of animal energy, but to its -final position. <i>The energetic transformations of the -animal end in thermal energy.</i></p> - -<p>This is the most novel part of the theory, and, if we -may say so, that least understood by physiologists -themselves. The energy resulting from the chemical -potential of food, having passed through the organism -(or simply through the organ which we are considering -in action), and having given rise to phenomenal appearances -more or less diversified, more or less dim or -clear, obscure or obvious, which are the characteristic -or still irreducible manifestations of vitality, finally<span class="pagenum" id="Page_113">[Pg 113]</span> -returns to the physical world. This return takes -place (with certain exceptions which will be presently -indicated) under the ultimate form of thermal energy. -This we are taught by experiment. The phenomena -of functional activity are exothermal.</p> - -<p>Real vital phenomena thus lie between the chemical -energy which gives rise to them, and the thermal -phenomena to which they in their turn give rise. The -place of the vital fact in the cycle of universal energy -is therefore completely determined. This conclusion -is of the utmost importance to biology. It may be -expressed in a concise formula which sums up in a -few words all that natural philosophy can teach as to -energetics applied to living beings. “Vital energy is -a transformation of chemical energy into thermal -energy.”</p> - -<p><i>Exceptions.</i>—There are some exceptions to the -rigour of this statement, but they are not many in -number. We must first of all remark that it applies -to <i>animal life</i> alone.</p> - -<p>In the case of vegetables, looked at as a whole, the -law must be modified. Their vital energy has another -origin, and another final form. Instead of being the -destroyers of chemical potential energy, they are its -creators. They build up by means of the inert and -simple materials afforded them by the atmosphere -and the soil, the immediate principles by which their -cells are filled. Their vital functional activity forms by -synthesis of the reserves, carbo-hydrates (sugars and -starches), fats, albuminoid nitrogenous materials—that -is to say, the same three principal categories of foods -as those used by animals.</p> - -<p>And to return to the latter, it should be observed -that thermal energy is not the only final form of vital<span class="pagenum" id="Page_114">[Pg 114]</span> -energy, as this dogmatic statement would have it -supposed. It is only the principle of the final forms. -The cycle of energy occasionally terminates in -mechanical energy (phenomena of motion) and in -a less degree in other energies; such as, for example, -the electrical energy produced by the functional activity -of the nerves and muscles in all animals, or in the -functional activity of special organs in rays, torpedo-fish, -and the malapterurus electricus, or finally, in the -photic energy of phosphorescent animals. But these -are secondary facts.</p> - -<p><i>Heat is an Excretum.</i>-The third principle of biological -energetics may be therefore thus enunciated:—<i>Vital -energy in its final form becomes thermal energy.</i> -This principle teaches us that if chemical energy is -the primitive generating form of vital energies, -thermal energy is the form of waste, of emunctory, -the degraded form as the physicists would say. Heat -is in the dynamical order an excretion of animal -life, as urea, carbonic acid and water, are excreta in -the substantial order. By a false interpretation of -the principle of the mechanical equivalence of heat, or -through ignorance of Carnot’s principle, certain -physiologists have fallen into error when they still -speak of the transformation of heat into motion or into -into electricity in the animal organism. Heat is transformed -into nothing in the animal organism. It is dissipated. -Its utility arises not from its energetic value, -but from the part it plays as a primer in the chemical -reactions, as has been explained with reference to the -general characteristics of chemical energy.</p> - -<p><i>The Effect of Energetics on our Knowledge of the -Relations of the Universe.</i>—The consequences of these -principles of energetic physiology, which give us so<span class="pagenum" id="Page_115">[Pg 115]</span> -much and which are so clear, are of the greatest -importance from the practical as well as from the -theoretical point of view.</p> - -<p>In the first place, they show us the position and the -rank of the phenomena of life in the universe as a -whole. They throw fresh light on the noble harmony -of the animal and vegetable kingdoms which Priestley, -Ingenhousz, Senebier, and the chemical school of the -beginning of the nineteenth century discovered, and -which was expounded by Dumas with incomparable -lucidity and brilliance. Energetics is expressed in a -line. “The animal world expends the energy accumulated -by the vegetable world.” It extends these -views beyond the living kingdoms. It shows how the -vegetable world itself draws its activity from the -energy radiated by the sun, and how animals restore -it again, in dissipated heat, to the cosmic medium. -It extends the harmony of the two kingdoms to the -whole of nature. The new science makes of the -whole universe one connected system.</p> - -<p>From a more limited point of view, and so that we -may not restrict ourselves to a consideration of the -domain of animal physiology, the laws of energetics -sum up and explain a multitude of facts and of -experimental laws—for example, the law of the intermittence -of physiological activity, the facts of fatigue, -the rôle and the general principles of alimentation, -and the conditions of muscular contraction.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_116">[Pg 116]</span></p> - -<h3 class="nobreak" id="CHAPTER_III_2">CHAPTER III.<br /> - -<small>ALIMENTARY ENERGETICS.</small></h3></div> - - -<p class="prel">Various Problems of Alimentation. § 1. <i>Food the source of -Energy and Matter.</i> The two forms of Energy afforded by -Food—Vital Energy, Thermal Energy. Food the source -of Heat. The rôle of Heat.—§ 2. <i>Measure of the output of -Energy</i>—by the Calometric Method—by the Chemical -Method.—§ 3. The regular type of Food, Biothermogenic, -and the irregular type, Thermogenic.—§ 4. Food considered -as the source of Heat. The Law of Surfaces. The limits -of Isodynamics.—§ 5. Plastic rôle of Food. Preponderance -of Nitrogenous Foods.</p> - - - -<p>Among the problems on which energetics has -thrown a vivid light we have mentioned alimentation, -muscular contraction, and, more general still, the -intermittence of vital functional activity. We shall -begin with the study of alimentation.</p> - -<p><i>The Different Problems of Alimentation.</i>—What is a -food? In what does alimentation consist? The -dictionary of the <i>Académie</i> will give us our first -answer. It tells us that the word food is applied to -“every kind of matter, whatever may be its nature, -which habitually serves or may serve for nutrition.” -This is very well put, but here again we must know -what nutrition is, and that is not a simple matter; in -fact, it practically means whatever is usually placed -on the table in a civilized and polished society. But<span class="pagenum" id="Page_117">[Pg 117]</span> -it is just the profound reasons for this traditional -practice that we are trying to discover.</p> - -<p>The problem of alimentation may be looked at in a -thousand ways. It is culinary, no doubt, and gastronomic; -but it is also economical and social, -agricultural, fiscal, hygienic, medical, and even moral. -But first and foremost, it is physiological. It comprises -and assumes the knowledge of the general -composition of foods, of their transformations in the -digestive apparatus, and their comparative utility in -the maintenance and the sound functional activity -of the organism. To this first group of subjects for -our discussion are attached others relating to the -effects of inanition, of insufficient alimentation, and of -over-feeding. And in order to throw light on all -these aspects of the problem of alimentation, we have -to lay bare the most intimate and delicate reactions by -which the organism is maintained and recruited, and, -in the words of a celebrated physiologist, “to penetrate -into the kitchen of vital phenomena.” And here -neither Apicius, nor Brillat-Savarin, nor Berchoux, -nor the moralists, nor the economists are of any use -to us as guides. We must appeal to the scientists, -who, following the example of Lavoisier, Berzelius, -Regnault, and Liebig, have applied to the study of -living beings the resources of general science, and -have thus founded <i>chemical biology</i>.</p> - -<p>This branch of science developed considerably in -the second half of the nineteenth century. It has now -its methods, its technique, its chairs at the universities, -its laboratories, and its literature. It has particularly -applied itself to the study of the “material changes” -or the <i>metabolism</i> of living beings, and with that -object in view it has done two things. In the first<span class="pagenum" id="Page_118">[Pg 118]</span> -place, it has determined the composition of the -constituent materials of the organism; then analyzing -qualitatively and quantitatively all that penetrates into -that organism in a given time—that is to say, all the -alimentary or respiratory ingesta, and all that issues -from the organism, <i>i.e.</i>, all the excreta, all the <i>egesta</i>,—it -has drawn up <i>nutritive balance sheets</i>, corresponding -to the various conditions of life, whether -naturally or artificially created. And thus we can -determine the alimentary régimes which give too -much, and which give too little, and which finally -restore equilibrium.</p> - -<p>We do not propose to give a detailed account of -this scientific movement. This may be done in monographs. -All we wish to indicate here is the most -general result of these laborious researches—that is -to say, the laws and the doctrines which are derived -from them, and the theories to which they have given -birth. It is by this alone that they are brought into -relation with general science, and may therefore -interest the reader. The facts of detail are never -lacking to the historian; it is more profitable to show -the movement of ideas. The theories of alimentation -bring into conflict very different conceptions of -the vital functional activity. And here we find a -confused medley of opinions on which it is not without -interest to endeavour to throw some light.</p> - - -<h4>§ 1. <span class="smcap">Food, a Source of Energy and Matter.</span></h4> - - -<p><i>Definitions of Food.</i>—Before the introduction into -physiology of the notion of energy, no one had -succeeded in giving an exact idea and a precise -definition of food and alimentation. Every physio<span class="pagenum" id="Page_119">[Pg 119]</span>logist -and medical man who attempted it had failed, -and this for various reasons.</p> - -<p>The general cause of this failure was that most definitions, -popular or technical, interposed the condition -that the food must be introduced into the digestive -apparatus. “It is,” said they, “a substance which -when introduced into the digestive tube undergoes, -etc., etc.” But plants draw food from the soil, and -they possess no digestive apparatus; many animals -have no intestinal tube; and in the case of certain -rotifera, the females possess a digestive apparatus, -while the males have none. Nevertheless all animals -feed.</p> - -<p>On the other hand, there are other substances than -those which use the digestive tract for the purpose of -entering the organism, and which are eminently useful -or necessary to the maintenance of life. In particular -we may mention oxygen.</p> - -<p>The distinctive feature of food is its <i>utility</i>—when -conveniently introduced or employed—to the living -being. Claude Bernard’s definition is this:—A substance -taken in the external medium “necessary for the -maintenance of the phenomena of the healthy organism -and for the reparation of the losses it constantly -suffers.” “A substance which supplies an element -necessary for the constitution of the organism, or -which <i>diminishes its disintegration</i>” (stored-up food); -this is the definition of C. Voit, the German physiologist. -M. Duclaux says, in his turn, but in far too -general terms, that it is a substance which contributes -to assure the sound functional activity of any of the -organs of the living being. None of these ways of -describing food gives a complete idea.</p> - -<p><i>Food, the Source of Energy and Matter.</i>—The inter<span class="pagenum" id="Page_120">[Pg 120]</span>vention -of the notion of energy enables us more -completely to understand the true nature of food. -We must, in fact, have recourse to the energetic conception -if we desire to take into account all that the -organism requires from food. It not only requires -<i>matter</i>, but also, and most important of all, energy.</p> - -<p>Investigators so far concentrated their thoughts exclusively -on the necessity of a supply of matter—that -is to say, they only looked upon one side of the -problem. The living body presents, at each of its -points, an uninterrupted series of disintegrations and -reconstitutions, the materials being supplied from -without by alimentation, and rejected by excretion. -Cuvier gave to this unceasing circulation of ambient -matter throughout the vital world the name of <i>vital -vortex</i>, and he rightly saw in it the characteristic of -nutrition, and the distinctive feature of life.</p> - -<p>This idea of the <i>cycle of matter</i> has been completed -in our own time by that of the <i>cycle of -energy</i>. All the phenomena of the universe, and -therefore those of life, are conceived of as energetic -transformations. We now look at them in their relationship -instead of considering them individually as of old. -Each has an antecedent and a consequent unity with -which it is connected in magnitude by the law of -equivalents taught us by contemporary physics. And -thus we may conceive of their succession as the -cycle of a kind of indestructible agent, which changes -only apparently, or assumes another form as it passes -from one to the other, but its magnitude remains -unaltered. This is energy. Thus, in the living being -there is not only a circulation of matter, but also a -circulation of energy.</p> - -<p>The most general result of research in physiological<span class="pagenum" id="Page_121">[Pg 121]</span> -chemistry from the time of Lavoisier down to our own -day has been to teach us that <i>the antecedent of the -vital phenomenon is always a chemical phenomenon</i>. -The vital energies are derived from the potential -chemical energy accumulated in the immediate constituent -principles of the organism. In the same way -<i>the consequent phenomenon of the vital phenomenon is in -general a thermal phenomenon</i>. The final form of -vital energy is thermal energy. These three assertions -as to the nature, the origin, and the final form of vital -phenomena constitute the three fundamental principles, -the three laws, of biological energetics.</p> - -<p><i>Food, a Source of Heat. It is not quâ source of heat -that food is the source of vital energy.</i>—The place of -vital energy in the cycle of universal energy is completely -determined. It lies between the chemical -energy which is its generating form and the thermal -energy which is its form of disappearance, of breakdown, -the “degraded form,” as the physicists say. -Hence we have a result which can be immediately -applied in the theory of food—namely, that heat is in -the dynamical order an excretum of the animal life -rejected by the living being, just as in the substantial -order, urea, carbonic acid and water, are the materials -used up and again rejected by it. We therefore must -not think of the transformation in the animal organism -of heat into vital energy, as certain physiologists -always do. Nor must we think, with Béclard, of its -transformation into muscular movement; or, as others -have maintained, into animal electricity. This is not -only an error of doctrine but an error of fact. It -proceeds from a false interpretation of the principle of -the mechanical equivalent of heat and a misunderstanding -of Carnot’s principle. Thermal energy does<span class="pagenum" id="Page_122">[Pg 122]</span> -not repeat the course of the energetic flux in the -animal organism. The heat is not transformed into -anything. It is simply dissipated.</p> - -<p><i>The Part played by Animal Heat as a Condition of -Physiological Manifestations.</i>—Does this mean that -heat is useless to life in the very beings in which it is -most abundantly produced—<i>i.e.</i>, in man and in the -warm-blooded vertebrates? So far from this being so, -it is necessary to life. But its utility has a peculiar -character which must neither be misunderstood nor -exaggerated. It is not transformed into chemical -or vital reactions, but merely creates for them a -favourable condition.</p> - -<p>According to the first principle of energetics, for -the vital fact to be derived from the thermal fact, the -heat must be preliminarily transformed into chemical -energy, since chemical energy is necessarily an antecedent -and generating form of vital energy. Now -this regressive transformation is impossible according -to the current theories of general physics. The part -played by heat in the act of chemical combination is -that of a primer to the reaction. It consists in placing -the reacting bodies, by changing their state or by -modifying their temperature, in the condition in which -they ought to be for the chemical forces to come into -play. For example, in the combination of hydrogen -and oxygen by setting light to an explosive mixture, -heat only acts as a primer to the phenomenon, because -the two gases which are passive at ordinary temperatures, -require to be raised to 400° C. before chemical -affinity comes into play. And so it is with the -reactions which go on in the organism. They have -a maximum temperature, and the part played by -animal heat is to furnish them with it.</p> - -<p><span class="pagenum" id="Page_123">[Pg 123]</span></p> - -<p>It follows that heat intervenes in animal life in two -capacities—first and foremost as <i>excretum</i>, or end of -the vital phenomenon, of <i>physiological work</i>; and on -the other hand, as a <i>condition</i> or <i>primer</i> of the chemical -reactions of the organism; and generally, as a favourable -condition for the appearance of the physiological -manifestations of living matter. Thus, it is not -dissipated in sheer waste.</p> - -<p>I was led to adopt these views some years ago -from certain experiments on the rôle played in food by -alcohol. I did not then know that they had already -been expressed by one of the masters of contemporary -physiology, M. A. Chauveau, and that they were -related in his mind to a series of conceptions and of -researches of great interest, in the development of -which I have since then taken a share.</p> - -<p><i>Two Forms of Energy supplied to Animals by Food.</i>—To -say that food is simultaneously a supply of -energy and a supply of matter, is really to express in -a single sentence the fundamental conception of -biology, in virtue of which life brings into play no -substratum or characteristic dynamism. According -to this, the living being appears to us as the -seat of an incessant circulation of matter and energy, -starting from the external world and returning -to it. All food is nothing but this matter and this -energy. All its characteristics, our views as to its -rôle, its evolution, all the rules of alimentation are -simple consequences of this principle, interpreted by -the light of energetics.</p> - -<p>And first of all, let us ask what forms of energy are -afforded by food? It is easy to see that there are -two—food is essentially a source of chemical energy; -and secondarily and accessorily, it is a source of heat.<span class="pagenum" id="Page_124">[Pg 124]</span> -Chemical energy is the only energy, according to the -second law of energetics, which may be transformed -into vital energy. It is true at any rate for animals; -for in plants it is otherwise. There the vital cycle has -neither the same point of departure nor the same final -position. The circulation of energy does not take -place in the same manner.</p> - -<p>On the other hand, and this we are taught by the -third law, energy brought into play in vital phenomena -is finally liberated and restored to the physical -world in the form of heat. We have just said that -this release of heat is employed in raising the temperature -of the living being. It is animal heat.</p> - -<p>Thus there are two forms of energy supplied by -food, chemical and thermal.</p> - -<p>It must be added that these are not the only forms, -but the principal, and by far the most important. It is -not absolutely true that heat is the only outcome of the -vital cycle. It is only so in the subject in repose, contented -to live idly without doing external mechanical -work, without lifting a tool or a weight, even that of its -own body. And again, speaking in this way, we neglect -all the movements and all the mechanical work which -is done without exercise of the volition, by the beating -of the heart and of the arteries, the movements of -respiration, and the contractions of the digestive tube.</p> - -<p>Mechanical work is, in fact, another possible termination -of the cycle of energy. But there is no -longer anything necessary or inevitable in this, since -motion and the use of force are in a certain measure -subordinated to the capricious volition of the animal.<a id="FNanchor_11" href="#Footnote_11" class="fnanchor">[11]</a></p> -<p><span class="pagenum" id="Page_125">[Pg 125]</span></p> -<p>At other times, again, it is an electrical phenomenon -which terminates the vital cycle, and it is, in fact, in -this way that things happen in the functional activity -of the nerves and muscles in all animals, and in the -functional activity of the electrical organ in fish, -such as the ray and the torpedo. Finally, the termination -may be a photic phenomenon, and this is -what happens in phosphorescent animals.</p> - -<p>It is idle to diminish the power of these principles -by proceeding to enumerate the whole of the exceptions -to their validity. We know perfectly well -that there are no absolute principles in nature. Let -us say, then, that the energy which temporarily -animates the living being is furnished to it by the -external world under the exclusive form of potential -chemical energy; but that, if there is only one door of -entry, there are two exits. It may return to the external -world in the principal form of thermal energy -and in the accessory form of mechanical energy.</p> - - -<h4><span class="smcap">§ 2. Measurement of the Supply Of -Alimentary Energy.</span></h4> - -<p><i>Calorimetric Method.</i>—From what has preceded it -is clear that if the energetic <i>flux</i> which circulates -through the animal emerges, <i>in toto</i>, in the state of -heat, the measurement of this heat becomes the<span class="pagenum" id="Page_126">[Pg 126]</span> -measurement of the vital energy itself, for the origin -of which we must go back to the food. If the flux is -divided into two currents, mechanical and thermal, -they must both be measured and the sum of their -values taken. If the animal does not produce mechanical -work, and all ends in heat, we have only to -capture, by means of a calorimeter, this energetic flux -as it emerges, and thus measure in magnitude and -numerically the energy in motion in the living being. -Physiologists use for this purpose various types of -apparatus. Lavoisier and Laplace used an ice calorimeter—that -is to say, a block of ice in which they -shut up a small animal, such as a guinea-pig; they -then measured its thermal production by the quantity -of ice it caused to melt. In one of their experiments, -for instance, they found that a guinea-pig had melted -341 grammes of ice in the space of ten hours, and had -therefore set free 27 Calories.</p> - -<p>But since those days more perfect instruments have -been invented. M. d’Arsonval employed an air calorimeter, -which is nothing but a differential thermometer -very ingeniously arranged, and giving an automatic -record. Messrs. Rosenthal, Richet, Hirn and Kaufmann, -and Lefèvre have used more or less simplified -or complicated air calorimeters. Others, following -the example of Dulong and Despretz, have used -calorimeters of air and mercury, or with Liebermester, -Winternitz, and J. Lefèvre (of Havre), have had -recourse to baths. Here, then, there is a considerable -movement of research which has led to the discovery -of very interesting facts.</p> - -<p><i>Measurement of the Supply of Alimentary Energy -by the Chemical Method.</i>—We may again reach our -result in another way. Instead of surprising the cur<span class="pagenum" id="Page_127">[Pg 127]</span>rent -of energy as it emerges and in the form of -heat, we may try and capture it at its entry in the -form of potential chemical energy.</p> - -<p>The evaluation of potential chemical energy may -be effected with the same unit of measurement as the -preceding—that is to say, the Calorie. If we consider -man and mammals, for example, we know that there -is only apparently an infinite variety in their foods. -We may say that they feed on only three substances. -It is a very remarkable fact that all the complexity -and multiplicity of foods, fruits, grains, leaves, animal -tissues, and vegetable products of which use is made, -reduce to so great a simplicity and uniformity, that all -these substances are of three types only: albuminoids, -such as albumen or white of egg—foods of animal -origin or varieties of albumen; carbo-hydrates, which -are more or less disguised varieties of sugar; and -finally, fats.</p> - -<p>Here, then, from the chemical point of view, leaving -out certain mineral substances, are the principal -categories of alimentary substances. Here, with the -oxygen that is brought in by respiration, is everything -that penetrates the organism.</p> - -<p>And now, what comes out of the organism? Three -things only, water, carbonic acid, and urea. But the -former are the products of the combustion of the -latter. If we consider an adult organism in perfect -equilibrium, which varies throughout the experiment -neither in weight nor in composition, we may say that -the receipts balance the expenditure. Albumen, sugar, -fat, plus the oxygen brought in, balance quantitatively -the water, carbonic acid, and urea expelled. Things -happen, in fact, as if the foods of the three categories -were burned up more or less completely by the oxygen.</p> - -<p><span class="pagenum" id="Page_128">[Pg 128]</span></p> - -<p>It is this combustion that we have known since the -days of Lavoisier to be the source of animal heat. -We can easily determine the quantity of heat left by -albumen passing into the state of urea, and by the -starch, the sugars, and the fats reduced to the state of -water and carbonic acid. This quantity of heat does -not depend on the variety of the unknown intermediary -products which have been formed in the -organism. Berthelot has shown that this quantity of -heat which measures the chemical energy liberated by -these substances is identical with the quantity obtained -by burning the sugar and the fats in a chemical -apparatus, in a calorimetric bomb, until we get carbonic -acid and water, and by burning albumen till we get -urea. This result is a consequence of Berthelot’s -<i>principle of initial and final states</i>. The liberated -heat only depends on the initial and final states, and -not on the intermediary states. The heat left in the -economy by the food being the same as that left in -the calorimetric bomb, it is easy for the chemist to -determine it. It has thus been discovered that one -gramme of albumen produces 4.8 Calories, one gramme -of sugar 4.2 Calories, and one gramme of fat 9.4 -Calories. We thus gather what a given ration—a mixture -in certain proportions of these different kinds of -foods—supplies to the organism and what energy -it gives it, measured in Calories.</p> - -<p>The calculation may be carried out to a high degree -of accuracy if, instead of confining ourselves to the -broad features of the problem, we enter into rigorous -detail. It is only, in fact, approximately that we have -reduced all foods to albumen, sugar, and fat, and all -excreta to water, carbonic acid, and urea.</p> - -<p>The reality is a little more complicated. There<span class="pagenum" id="Page_129">[Pg 129]</span> -are varieties of albumen, carbo-hydrates, and fatty -bodies, the heats of combustion of which in the -organism oscillate in the neighbourhood of the numbers -4.8, 4.2, and 9.4. Each of these bodies has been -individually examined, and numerical tables have -been drawn up by Berthelot, Rubner, Stohmann, Van -Noorden, etc. The tables exhibit the thermal value -or energetic value of very different kinds of foods.</p> - -<p>In our climate, the adult average man, doing no -laborious work, daily consumes a maintenance ration -composed, as a rule, of 100 grammes of albuminoids, -49 grammes of fats, and 403 grammes of carbo-hydrates. -This ration has an energetic value of 2,600 -Calories.</p> - -<p>It is therefore, thanks to the victories won in the -field of thermo-chemistry, and to the principles laid -down since 1864 by M. Berthelot, that this second -method of attack on nutritive dynamism has been -rendered possible. Physiologists, by the aid of these -methods, have drawn up <i>balance-sheets of energy</i> for -living beings just as they had previously established -<i>balance-sheets of matter</i>.</p> - -<p>Now, it is precisely researches of this kind that we -have indicated here as a consequence of biological -energetics, which in reality have helped to build up -that principle. These researches have shown us that, -in conformity with the <i>principles of thermodynamics</i>, -there was not, in fact, in the organism, any transformation -of heat into mechanical work, as the -physiologists for a short time supposed, on the -authority of Berthelot. With the help of our theory -this mistake is no longer possible. The doctrine of -energetics shows us in fact the current of energy -dividing itself, as it issues from the living being, into<span class="pagenum" id="Page_130">[Pg 130]</span> -two divergent branches, the one thermal and the -other mechanical, external the one to the other -although both issuing from the same common trunk, -and having between them no relation but this, that -the sum of their discharges represents the total of the -energy in motion. Let us now translate these very -simple notions into the more or less barbarous jargon -in use in physiology. We shall be convinced as we -go on of the truth of the saying of Buffon, that “the -language of science is more difficult to learn than the -science itself.” We shall say, then, that chemical -energy, that the unit of weight of the food which may -be placed in the organism, constitutes the alimentary -<i>potential</i>, the <i>energetic value</i> of this substance, its -<i>dynamogenic power</i>. It is measured in units of heat, -in Calories, which the substance may leave in the -organism. The evaluation is made according to the -principles of thermo-chemistry, by means of the -numerical tables of Berthelot, Rubner, and Stohmann. -The same number also expresses the <i>thermogenic -power</i>, virtual or theoretical, of the alimentary substance. -This energy being destined to be transformed -into <i>vital energies</i> (Chauveau’s <i>physiological work</i>, -<i>physiological energy</i>), the dynamogenic or thermogenic -value of the food is at the same time its biogenetic -value. Two weights of different foods which supply -the organism with the same number of Calories,—<i>i.e.</i> -for which these numerical values are the same,—will be -called <i>isodynamic</i> or <i>isodynamogenic</i>, <i>isobiogenetic</i>, <i>isoenergetic</i> -weights. They will be equivalent from the -point of view of their alimentary value. And finally, -if, as is usually the case, the cycle of energy ends in -the production of heat, the food which has been -utilized for this purpose has a real <i>thermogenic value</i>,<span class="pagenum" id="Page_131">[Pg 131]</span> -identical with its theoretical thermogenic value. In -this case it might be determined experimentally by -direct calorimetry, measuring the heat produced by -the animal supposed absolutely unchanged and identical -before and after the consumption of the food.</p> - - -<h4>§ 3. <span class="smcap">Different Types of Foods. The Regular, -Biothermogenic Type and the Irregular, -Thermogenic Type.</span></h4> - - -<p>Food is a source of thermal energy for the organism -because it is decomposed within it, and undergoes -within it a chemical degradation. Physiological -chemistry tells us that whatever be the manner in -which it is broken up, it always results in the same -body and always sets free the same quantity of heat. -But if the point of departure and the point of arrival -are the same, it is possible that the path pursued is -not constantly identical. For example, one gramme -of fat will always give the same quantity of heat, -9.4 Calories, and will always come to its final state -of carbonic acid and water; but from the fat to -the mixture of carbonic acid gas and water there -are many different intermediaries. In a word we -get the conception of varied cycles of alimentary -evolutions.</p> - -<p>From the point of view of the heat produced it has -just been said that these cycles are equivalent. But -are they equivalent from the vital point of view? -This is an essential question.</p> - -<p>Let us imagine the most ordinary alternative. -Food passes from the natural to the final state after -being incorporated with the elements of the tissues,<span class="pagenum" id="Page_132">[Pg 132]</span> -and after having taken part in the vital operations. -The chemical potential only passes into thermal -energy after having passed through a certain intermediary -phase of vital energy. This is the normal -case, <i>the regular type of alimentary evolution</i>. It may -be said in this case that the food has fulfilled the -whole of its function, it has served for the vital -functional activity before producing heat. It has -been <i>biothermogenic</i>.</p> - -<p><i>The irregular or pure thermogenic type.</i>—And now -let us conceive of the most simple <i>irregular or -aberrant type</i>. Food passes from the initial to the -final state without incorporation in the living cells of -the organism, and without taking part in the vital -functional activity. It remains confined in the blood -and the circulating liquids, but it undergoes in the -end, however, the same molecular disintegration as -before, and sets free the same quantity of heat -Its chemical energy changes at once into thermal -energy. Food is a <i>pure thermogen</i>. It has fulfilled -only one part of its work. It has been of slight -vital utility.</p> - -<p>Does this ever occur in reality? Are there foods -which would be only <i>pure thermogens</i>—that is to -say, which would not in reality be incorporated with -the living anatomical elements, which would form no -part of them either in a state of provisory constituents -of the living protoplasm, or in the state of reserve-stuff; -which would remain in the internal medium, in -the blood and the lymph, and would there undergo -their chemical evolution? Or again, if the whole of -the food does not escape assimilation, would it be -possible for part to escape it? Would it be possible -for one part of the same alimentary substance to be<span class="pagenum" id="Page_133">[Pg 133]</span> -incorporated, and for the rest to be kept in the blood -or the lymph, in the circulating liquids <i>ad limina -corporis</i>, so to speak? In other words, can the same -food be according to circumstances a <i>biothermogen</i> or -a <i>pure thermogen</i>? Some physiologists—Fick of -Wurzburg, for instance—have claimed that this is -really the case for most nitrogenous elements, carbohydrates, -and fats; all would be capable of evolving -according to the two types. On the other hand, Zuntz -and von Mering have absolutely denied the existence -of the aberrant or pure thermogenic type. No substances -would be directly decomposed in the organic -liquids apart from the functional intervention of the -histological elements. Finally, other authors teach -that there is a small number of alimentary substances -which thus undergoes direct combustion, and among -them is alcohol.</p> - -<p><i>Liebig’s Superfluous Consumption.</i>—Liebig’s <i>theory -of superfluous consumption</i> and Voit’s <i>theory of the -circulating albumen</i> assert that the proteid foods -undergo partial direct combustion in the blood vessels. -The organism only incorporates what is necessary -for physiological requirements. As for the surplus -of the food that is offered it, it accepts it, and, so -to speak, squanders it; it burns it directly; and -we have a “sumptuary” consumption, consumption -<i>de luxe</i>.</p> - -<p>In this connection arose a celebrated discussion -which still divides physiologists. If we disengage -the essential body of the discussion from all -that envelops it, we see that it is fundamentally a -question of deciding whether a food always follows the -same evolution whatever the circumstances may be, -and particularly when it is introduced in great excess.<span class="pagenum" id="Page_134">[Pg 134]</span> -Liebig thought that the superabundant part, escaping -the ordinary process, was destroyed by direct combustion. -He affirmed, for instance, that nitrogenous -substances in excess were directly burned in the blood -instead of passing through their usual cycle of vital -operations. We might express the same idea by -saying that they then undergo an accelerated -evolution. Instead of passing through the blood in -the anatomical element, to return in the dismembered -form from the anatomical element to the blood, -their breaking up takes place in the blood itself. -They save a displacement, and therefore in reality -remain external to the construction of the living -edifice. Their energy, crossing the intermediary vital -stage, passes with a leap from the chemical to the -thermal form. Liebig’s doctrine reduced to this -fundamental idea deserved to survive, but mistakes -in minor details involved its ruin.</p> - -<p><i>Voit’s Circulating Albumen.</i>—A few years later -C. Voit, a celebrated physiological chemist of Munich, -revived it in a more extravagant form. He held -that almost the whole of the albuminoid element -is burned directly in the blood. He interpreted -certain experiments on the utilization of nitrogenous -foods by imagining that these substances -when introduced into the blood were divided as a -result of digestion into two parts: the one very small, -which was incorporated with the living elements, and -passed into the stage of <i>organized albumen</i>, the other, -corresponding to the greater part of the alimentary -albumen, remained mingled with the blood and -lymph, and was subjected in this medium to direct -combustion. This was <i>circulating albumen</i>. In this -theory the tissues are almost stable; the organic<span class="pagenum" id="Page_135">[Pg 135]</span> -liquids alone are subjected to oxydizing transformations, -to nutritive metabolism. The accelerated -evolution, which Liebig considered as an exceptional -case, was to C. Voit the rule.</p> - -<p><i>Current Ideas as to the Rôle of Foods.</i>—The ideas -of to-day are not those of Voit; but they do not, -however, differ from them essentially. We no longer -admit that the greater part of the ingested and -digested albumen remains confined in the circulating -medium external to the anatomical elements. It is -held, with Pflüger and the school of Bonn, that it -penetrates the anatomical element and is incorporated -in it; but in agreement with Voit it is believed -that a very small part is assimilated to the really -living matter, to the protoplasm properly so called; -the greater part is deposited in the cellular element -as reserve-stuff. The material, properly so called, of -the living machine does not undergo destruction and -reparation as extensively as our predecessors supposed. -There is no need for great reparation. On the contrary, -the physiological activity consumes to a great -extent the reserve-stuff. And the greater part of -the food, after having undergone suitable elaboration, -serves to replace the reserve-stuff destroyed -in each anatomical element by the vital functional -activity.</p> - -<p><i>Experimental Facts.</i>—Among the facts which -brought physiologists of the school of Voit to believe -that most foods do not get beyond the internal -medium, there is one which may well be mentioned -here. It has been observed that the consumption of -oxygen in respiration increases notably (about a fifth -of its value) immediately after a meal. What does -this mean? The interval is too short for the digested<span class="pagenum" id="Page_136">[Pg 136]</span> -alimentary substances to have been elaborated and -incorporated in the living cells. It is supposed that -an appreciable time is required for this complete -assimilation. The products of alimentary digestion -are therefore in all probability still in the blood, and -in the interstitial liquids in communication with it. -The increase of oxygen consumed would show that a -considerable portion of these nutritive substances -absorbed and passed into the blood would be oxydized -and then and there destroyed. But this -interpretation, however probable it may be, does not -really fit in with the facts in such a way that we may -consider it as proved. Certain experiments by Zuntz -and Mering are opposed to the idea that combustion -in the blood is easy. These physiologists injected -certain oxydizable substances into the vessels without -being able to detect any instantaneous oxidation. -It is only fair to add that against these fruitless -attempts other more fortunate experiments may be -quoted.</p> - -<p><i>Category of Purely Thermogenic Foods, with Accelerated -Evolution. Alcohol. Acids of Fruits.</i>—The -accelerated evolution of foods—an evolution -which takes place in the blood, that is to say outside -the really living elements—remains, therefore, very -uncertain as far as ordinary food is concerned. It -has been thought that it was a little less uncertain -as far as the special category of alcohol, acids of -fruits, and glycerine is concerned.</p> - -<p>Some authors consider these bodies as pure -thermogens. When alcohol is ingested in moderate -doses, they say that about a tenth of the -quantity absorbed becomes fixed in the living tissues; -the rest is “circulating alcohol.” It is oxidized<span class="pagenum" id="Page_137">[Pg 137]</span> -directly in the blood and in the lymph, without intervening -in the vital functions other than by the heat -it produces. From the point of view of the energetic -theory these are not real foods, because their potential -energy is not transformed into any kind of vital -energy, but passes at once to the thermal form. On -the other hand, other physiologists look upon alcohol -as really a food. According to them everything is -called a food which is transformed in the organism -with the production of heat; and they measure the -nutritive value of a substance by the number of -Calories it can give up to the organism. So that -alcohol would be a better food than carbohydrated -and nitrogenous substances. A definite quantity of -alcohol, a gramme for instance, is equivalent from -the thermal point of view to 1.66 grammes of sugar, -1.44 of albumen, or 0.73 of fat. These quantities -would be <i>isodynamic</i>.</p> - -<p>Experiment has not entirely decided for or against -this theory. However, the first tests have not been -very favourable to it. The researches of C. von -Noorden and his pupils, Stammreich and Miura, have -clearly and directly established that alcohol cannot -be substituted in a maintenance ration for an exactly -isodynamic quantity of carbohydrates. If the substitution -is effected, a ration only just capable of -maintaining the organism in equilibrium becomes insufficient. -The animal decreases in weight. It loses -more nitrogenous matter than it can recover from -its diet, and this situation cannot be sustained for -long. On the other hand, the celebrated researches -of the American physiologist, Atwater, would plead, -on the contrary, in favour of almost isodynamic substitution. -Finally, Duclaux has shown that alcohol<span class="pagenum" id="Page_138">[Pg 138]</span> -is a real food, biothermogenic for certain vegetable -organisms. But urea is also a food for <i>micrococcus -ureæ</i>. It does not follow that it is a food for mammals. -We have not reached the solution yet—<i>adhuc -sub judice</i>.</p> - -<p><i>Conclusion: The Energetic Character of Food.</i>—To -sum up we have confined ourselves, in what has been -said, to the consideration of a single character of -food, and really the most essential, its energetic -character. Food must furnish energy to the organism, -and for that purpose it is decomposed and broken up -within it, and issues from it simplified. It is thus, -for instance, that the fats, which from the chemical -point of view are complicated molecular edifices, -escape in the form of carbonic acid and water. And -so it is with carbo-hydrates, starchy and sugary -substances. This is because these compounds -descend to a lower degree of complexity during their -passage through the organism, and by this drop, as it -were, they get rid of the chemical energy which they -contained in the potential state. Thermo-chemistry -enables us to deduce from the comparison of the -initial and final states the value of the energy -absorbed by the living being. This energetic, dynamogenic -or thermogenic value, thus gives a measure of -the alimentary capacity of the substance. A gramme -of fat, for instance, gives to the organism a quantity -of energy equivalent to 9.4 Calories; the thermogenic -value of the albumenoids is 4.8 Calories. -The thermogenic or thermal value of carbohydrates -is less than 4.7 calories. This being so, we understand -why the animal is nourished by foods which -are products very high in the scale of chemical -complexity.</p> - -<p><span class="pagenum" id="Page_139">[Pg 139]</span></p> - - -<h4>§ 4. <span class="smcap">Food considered exclusivelyy as -Source of Heat.</span></h4> - - -<p>We have seen that food is, in the first place, a -source of <i>chemical energy</i>; and, in the second place, -a source of <i>vital energy</i>—finally, and consequently, a -source of thermal energy. It is this last point of -view which has exclusively struck the attention of -certain physiologists, and hence has arisen a peculiar -manner of conceiving the rôle of food. It consists in -looking on food as a source of thermal energy.</p> - -<p>This conception is easily applied to warm-blooded -animals, but to them exclusively—and this is where -it first fails. The animal is warmer than the environment -in general. It is constantly giving out heat to -it. To repair this loss of heat it takes in food in -exact proportion to the loss it sustains. When it is a -question of cold-blooded vertebrates, which live in -water and in most cases have an internal temperature -which is not distinguishable from that of -the environment, we see less clearly the thermal rôle -of food. It seems then that the production of heat -is an episodic phenomenon, not existing for itself.</p> - -<p>However that may be, food is in the second place -a source of thermal energy for the organism. Can it -be said, inversely, that every substance which we introduce -into the economy, and which is there broken -up and gives off heat, is a food? This is a moot -point. We dealt just now with purely thermogenic -foods. However, most physiologists are inclined to -give a positive answer. In their eyes the idea of food -cannot be considered apart from the fact of the production -of heat. They take the effect for the<span class="pagenum" id="Page_140">[Pg 140]</span> -cause. To these physiologists everything ingested is -called food, if it gives off heat within the body.</p> - -<p>To be heated by food is, indeed, an imperious -necessity for the higher animals. If this need be not -satisfied the functional activities become enervated; -the animal falls into a state of torpor; and if it is -capable of attenuated, of more or less latent, life it -sleeps in a state of hibernation; but if it is not -capable of this, it dies. The warm-blooded animal -with a fixed temperature is so organized that this -constancy of temperature is necessary to the exercise -and to the conservation of life. To maintain this -indispensable temperature there must be a continual -supply of thermal energy. According to this, the -necessity of alimentation is confused with the -necessity of a supply of heat to cover the deficit -which is due to the inevitable cooling of the organism. -This is the point of view taken up by theorists, and -we cannot say that they have no right to do so. We -can only protest against the exaggeration of this -principle, and the subordination of the other rôles of -food to this single role as a thermogen. It is the -magnitude of the thermal losses which, according to -these physiologists, determines the need for food, and -regulates the total value of the maintenance ration. -From the quantitative view it is approximately true. -From the qualitative point of view it is false.</p> - -<p>Such is the theory opposed to the theory of -chemical and vital energy. It has on its side a large -number of experts, among whom are Rubner, -Stohmann, and von Noorden. It has been defended in an -article in the <i>Dictionnaire de Physiologie</i> by Ch. -Richet and Lapicque. They hold that thermogenesis -absolutely dominates the play of nutritive exchanges;<span class="pagenum" id="Page_141">[Pg 141]</span> -and it is the need for the production of heat that -regulates the total demand for Calories which every -organism requires from its ration. It is not because -it produces too much heat that the organism gets rid -of it peripherally: it is rather because it inevitably -disperses it that it is adapted to produce it.</p> - -<p><i>Rubner’s Experiments.</i>—This conception of the rôle -of alimentation is based on two arguments. The first -is furnished by Rubner’s last experiment (1893). A -dog in a calorimeter is kept alive for a rather long -period (two to twelve days); the quantity of heat -produced in this lapse of time is measured, and it is -compared with the heat afforded by the food. In all -cases the agreement is remarkable. But is it possible -that there should be no such agreement? Clearly no, -because there is a well-known regulating mechanism -which always exactly proportions the losses and the -gains of heat to the necessity of maintaining the fixed -internal temperature. This first argument is, therefore, -not conclusive.</p> - -<p>The second argument is drawn from what has been -called the <i>law of surfaces</i>, clearly perceived by Regnault -and Reiset in their celebrated memoir in 1849, -formulated by Rubner in 1884, and beautifully -demonstrated by Ch. Richet. In comparing the -maintenance rations for subjects of very different -weights, placed under very different conditions, it is -found that the food always introduces the same number -of Calories for the same extent of skin—<i>i.e.</i>, for -the same cooling surface. The numerical data -collected by E. Voit show that, under identical conditions, -warm-blooded animals daily expend the same -quantity of heat per unit of surface—namely, 1.036 -Calories per square yard. The average ration intro<span class="pagenum" id="Page_142">[Pg 142]</span>duces -exactly the amount of food which gives off -sensibly this number of Calories. Now, this is an -interesting fact, but, like the preceding, it has no -demonstrative force.</p> - -<p><i>Objections. The Limits of Isodynamism.</i>—On the -contrary, there are serious objections. The thermal -value of the nutritive principles only represents one -feature of their physiological rôle. In fact, animals -and man are capable of extracting the same profit -and the same results from rations in which one of the -foods is replaced by an <i>isodynamic</i> proportion of the -other two—that is to say, a proportion developing the -same quantity of heat. But this substitution has very -narrow limits. Isodynamism—that is to say, the -faculty that food has of supplying <i>pro ratâ</i> its thermal -values—is limited all round by exceptions. In the -first place, there are a few nitrogenous foods that no -other nutritive principle can supply; and besides, beyond -this minimum, when the supply takes place, it is -not perfect. Lying between the albuminoids and the -carbohydrates relatively to the fats, it is not between -these two categories relatively to nitrogenous substances -if the thermal power of food were the only -thing that had to be considered in it, the isodynamic -supply would not fail in a whole category of principles -such as alcohol, glycerin, and the fatty acids. Finally, -if the thermal power of a food is the sole measure of -its physiological utility, we are compelled to ask why -a dose of food may not be replaced by a dose of heat. -External warming might take the place of the internal -warming given by food. We might be ambitious -enough to substitute for rations of sugar and fat an -isodynamic quantity of heat-giving coal, and so -nourish the man by suitably warming his room. In<span class="pagenum" id="Page_143">[Pg 143]</span> -reality, food has many other offices to fulfill than -that of warming the body and of giving it energy—that -is to say, of providing for the functional activity -of the living machine. It must also serve to provide -for wear and tear. The organism needs a suitable -quantity of certain fixed principles, organic and -mineral. These substances are evidently intended to -replace those which have been involved in the cycle -of matter, and to reconstitute the organic material. -To these materials we may give the name of <i>histogenetic</i> -foods (repairing the tissues), or of <i>plastic</i> -foods.</p> - - -<h4>§ 5. <span class="smcap">The Plastic Rôle of Food.</span></h4> - - -<p><i>Opinions of the Early Physiologists.</i>—It is from this -point of view that the ancients regarded the rôle of -alimentation. Hippocrates, Aristotle, and Galen -believed in the existence of a unique nutritive substance, -existing in all the infinitely different bodies -that man and the animals utilize for their nourishment. -It was Lavoisier who first had the idea of a -dynamogenic or thermal rôle of foods. Finally, the -general view of these two species of attributes and -their marked distinction is due to J. Liebig, who -called them <i>plastic</i> and <i>dynamogenic</i> foods. In addition -he thought that the same substance should accumulate -the same attributes, and that this was the case with -the albuminoid foods, which were at once <i>plastic</i> and -<i>dynamogenic</i>.</p> - -<p><i>Preponderance of Nitrogenous Foods.</i>—Magendie, in -1836, was the pioneer who introduced in this interminable -list of foods the first simple division. He -divided them into proteid substances, still called<span class="pagenum" id="Page_144">[Pg 144]</span> -albuminoids, nitrogenous, quaternary, and <i>ternary -substances</i>. Proteid substances are capable of maintaining -life. Hence the preponderant importance -given by the eminent physiologist to this order of -foods. These results have since been verified. Pflüger, -of Bonn, gave a very convincing proof of this a few -years ago. He fed a dog, made it work, and finally -fattened it, by giving it nothing at all to eat but meat -from which had been extracted, as thoroughly as -possible, every other substance.<a id="FNanchor_12" href="#Footnote_12" class="fnanchor">[12]</a> The same experiment -showed that the organism can manufacture fats and -carbo-hydrates at the expense of the nitrogenous food, -when it does not find them ready formed in the ration. -The albumen will suffice for all the needs of energy and -and matter. To sum up, there is no necessary fat, no -carbohydrate is necessary; albuminoids alone are indispensable. -Theoretically, the animal and man alike -could maintain life by the exclusive use of proteid -food; but, practically, this is not possible for man, -because of the enormous amount of meat which -would have to be used (3 kilogrammes a day).</p> - -<p>Ordinary alimentation comprises a mixture of -three orders of substances, and to this mixture -albumen brings the plastic element materially necessary -for the reparation of the organism; it also is -the source of energy. The two other varieties only -bring energy. In this mixed regimen the quantity -of albumen must never descend below a certain -minimum. The efforts of physiologists of late years -have tended to fix with precision this minimum -ration of albuminoids—or as we may briefly put it,<span class="pagenum" id="Page_145">[Pg 145]</span> -of <i>albumen</i>—below which the organism would perish. -Voit had found 118 grammes of albumen necessary -for the average adult man weighing 70 kilos. This -figure is certainly too high. The Japanese doctors, -Mori, Tsuboï, and Murato, have shown that a considerable -portion of the population of Japan is -content with a diet much poorer in nitrogen, and -suffers no inconvenience. The Abyssinians, according -to Lapicque, ingest, on the average, only 67 -grammes of albumen per day. A Scandinavian physiologist, -Siven, experimenting on himself, found that -he could reduce the ration of albumen necessary to -the maintenance and equilibrium of the organism to -the lowest figures which have been yet reached—namely, -from 35 to 46 grammes a day. These -experiments, however, must be confirmed and interpreted. -Besides, it is important to point out that the -most advantageous ration of albumen requires to be -a good deal above the strictly sufficient quantity.</p> - -<p>It only remains to refer to several other recent -researches. The most important of many are those -published by M. Chauveau, on the reciprocal transformation -of the immediate principles in the organism -according to the conditions of its functioning and -the circumstances of its activity. To deal with -these researches with as much detail as they deserve, -we must study the physiology of muscular contraction -and of movement—that is to say, of muscular -energetics.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_146">[Pg 146]</span></p> - -<h2 class="nobreak" id="BOOK_III">BOOK III.</h2> - - -<p class="center">THE CHARACTERS COMMON TO LIVING BEINGS.</p> - - -<p class="prel">Chapter I. Summary: The doctrine of vital unity.—Chapter II. -The morphological unity of living beings.—Chapter III. -The chemical unity of living beings.—Chapter IV. The -mutability of living beings.—Chapter V. The specific -form, its acquisition, and reparation.—Chapter VI. Nutrition.</p> -</div> - - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<h3 class="nobreak" id="CHAPTER_I_3">CHAPTER I.<br /> - -<small>THE DOCTRINE OF VITAL UNITY.</small></h3></div> - - -<p class="prel">Phenomena common to all living beings—Theory of vital -duality—Unity in the formation of immediate principles—Unity -in the digestive acts—The common vital fund.</p> - - -<p>When we ask the various philosophical schools what -life is, some show us a chemical retort, and others -show us a soul. Whether vitalists or of the mechanical -school, these are the adversaries who since philosophy -began have vainly contested the possession of the -secret of life. We need not concern ourselves with this -eternal quarrel. We need not ask Pythagoras, Plato, -Aristotle, Hippocrates, Paracelsus, Van Helmont, -and Stahl what idea they formed of the vital -principle; nor need we probe to the depths the -ideas of living nature held by Epicurus, Democritus,<span class="pagenum" id="Page_147">[Pg 147]</span> -Boerhaave, Willis, and Lamettrie; nor need we -apply to the iatromechanicians nor to the chemists. -We may do better than that. We may ask nature -itself.</p> - -<p><i>Phenomena Common to Living Beings.</i>—Nature -shows us an infinite number of beings, animal or -vegetable, described in ordinary language as <i>living -beings</i>. This language implicitly assumes something -common to them all, a universal manner of being -which belongs to them without distinction, without -regard to differences of species, types, or kingdoms. -On the other hand, anatomical analysis teaches us -that animated beings and plants may be divided into -parts ever decreasing in complexity, of which the -last and the simplest is the <i>anatomical element</i>, the -<i>cell</i>, the microscopic organic unit which, too, is alive. -Common opinion suspects that all these beings, -whether entire as in the case of animal and vegetable -individuals, or fragmentary as in the case of -cellular elements, have the same manner of being, -and present the same body of common characteristics -which rightly gives them this unmistakable title of -living beings. Life then essentially would be this -manner of being, common to animals, vegetables, and -their elements. To seize in isolation these common, -necessary, and permanent features, and then to -synthetize them into a whole, will be the really -scientific method of defining life, and of explaining -its nature.</p> - -<p>And here then immediately arises a fundamental -question which gives one pause, a question of fact -which must be solved before we can go further. -Is there really a common manner of being in all -these things? Are <i>animal life, vegetable life</i>, and the<span class="pagenum" id="Page_148">[Pg 148]</span> -life of the elements or <i>elementary life</i>, all the same? -Is there a sum total of characteristics which may -define life in general?</p> - -<p>The physiologists, following in the steps of Claude -Bernard, respond in the affirmative. They accept as -valid and convincing the proof given of this vital -community by the illustrious experimentalist. However -there are some rare exceptions to this universal -assent. In this concert of approval there is at least -one discordant voice, that of M. F. Le Dantec.<a id="FNanchor_13" href="#Footnote_13" class="fnanchor">[13]</a></p> -<p><span class="pagenum" id="Page_149">[Pg 149]</span></p> -<p><i>The Doctrine of the Vital Duality of Animals and -Plants.</i>—There are, therefore, biologists who, in the -domain of theory and in virtue of more or less well-founded -conceptions or interpretations, separate -<i>elementary life</i> from other vital forms, and thus break -the bond of vital unity proclaimed by Claude Bernard. -This monistic doctrine at the outset met with other -opponents, and that, too, in the domain of facts. -But it triumphed over them and became established. -We have to deal with scientists like J. B. Dumas and -Boussingault, who drew a dividing line between -<i>animal life</i> and <i>vegetable life</i>.</p> - -<p>But let us in a few words recall to the reader this -victorious struggle of the monistic doctrine against -the dualism of the two kingdoms. If we consider an -animal in action, said the champions of vital dualism, -we agree that it feels, moves, breathes, digests, and -finally, that it destroys by a real operation of chemical -analysis the materials afforded to it by its ambient -world. It is in these phenomena that are manifested -its activity, its life. Now, added the dualists, plants -do not feel, do not move, do not breathe, and do not -digest. They build up from immediate principles, -by an operation of chemical synthesis, the materials -they borrow from the soil which bears them, or from -the atmosphere which surrounds them. There is, -therefore, nothing in common between the representatives -of the two kingdoms if we confine ourselves -to the examination of the actual phenomena which -take place in them. To find a resemblance between -the animal and the vegetable, said the dualists, we -must set aside what they <i>do</i>, for they do different, or -even contrary things. We must consider whence -they come and what they <i>become</i>. Both originate<span class="pagenum" id="Page_150">[Pg 150]</span> -in organisms similar to themselves. They grow, -evolve, and generate as they themselves were -generated. In other words, while their acts separate -plants from animals, their mode of origin and -evolution alone bring them together. Such analogies -are of no slight importance; but they were neutralized -by their dissimilarities, which were exaggerated by -the dualistic school.</p> - -<p>It is clear that the word <i>life</i> would lose all actual -significance to those who would reduce it to the -faculty of evolution, and who would separate all its -real manifestations in animated beings and in plants. -If there are two lives, the one animal and the other -vegetable, there are no more; or, what comes to the -same thing, there is an infinite number of lives which -have nothing in common but the name, or at most, -the possession of some secondary characteristics. -There are as many of them as there are different -beings, for each has its own particular evolution. -Here the specific is the negation of the general and -it destroys it instead of being subordinate to it. The -principle of life becomes for each being something as -individual as its own evolution. And this, if we -think it out, is how the philosophers look at life, and -it is the real reason of their disagreement with the -physiological school.</p> - -<p><i>Proof of the Monistic Theory.</i>—On the other hand, -under the disguise of living forms, the physiologist -recognizes the existence of an identical basis. His -trained ear marks amid the overcharged instrumentation -of the vital work the recognizable -undertones of a constant theme. It was the work of -Claude Bernard to bring this common basis to -light. He shows that plants live as animals do,<span class="pagenum" id="Page_151">[Pg 151]</span> -that they breathe, digest, have sensory reactions, -move essentially like animals, destroy and build up -in the same manner the immediate chemical principles. -For that purpose it was necessary to pass in -review, examining them from their foundation and -distinguishing the essential from the secondary, the -different vital manifestations—digestion, respiration, -sensibility, motility, and nutrition. This is what -Claude Bernard did in his work <i>Sur les Phénomènes -de la vie communs aux animaux et aux plantes</i>. We -need only to sketch in broad outline the characteristic -features of his lengthy demonstration.</p> - -<p><i>Unity in the Formation of Immediate Chemical -Principles.</i>—The first and most important of the -differences pointed out between the life of animals -and that of plants was relative to the formation of -immediate principles. On this ground, indeed, vital -dualism raised its fortress. The animal kingdom -was considered in its totality as the parasite of the -vegetable kingdom. To J. B. Dumas, animals, -whatever they may be, make neither fat nor any -elementary organic matter; they borrow all their -foods, whether they be sugars or starches, fats or -nitrogenous substances, from the vegetable kingdom. -About the year 1843 the researches of the chemists, -and of Payen in particular, succeeded in proving the -presence, almost constant, of fatty matters in vegetables; -and, further, these matters existed there in -proportions more than sufficient to explain how -the beast which fed upon them was fattened. The -chemists attributed to nature as much practical sense -as they themselves possessed; and since the hay and -the grass of the ration brought fat ready made to the -horse, the cow, and the sheep, they declared that the<span class="pagenum" id="Page_152">[Pg 152]</span> -animal organism had nothing whatever to do but to -put this food into the tissues, or to arrange for it to -pass into the milk. But nature is not so wise and -economical as was supposed at the Académie des -Sciences. After a memorable debate, in which -Dumas, Boussingault, Payen, Liebig, Persoz, Chossat, -Milne-Edwards, and Flourens took part, and, later on, -Berthelot and Claude Bernard, it was agreed that -the animal does not grow fat from the fatty food -which is supplied it, and that it makes its own fat -just as the vegetable does, but in another manner. -In the same way sugar, the normal constituent substance -necessary for the nutrition of animals and -plants, instead of being a vegetable product passing -by alimentation from the herbivorous animals and -thence to the carnivorous, is manufactured by the -animal itself. Generally speaking, immediate principles -have an equal claim to existence in the two -kingdoms. Both form and destroy the substances -indispensable to life.</p> - -<p>Here, then, one of the barriers between animal life -and vegetable life is overthrown and destroyed.</p> - -<p><i>Unity of Digestive Acts in Animals and Plants.</i>—Similarly, -another barrier falls if we show that -digestion, long considered the exclusive function of -animals, and, in particular, of the higher animals, is -in reality universal.</p> - -<p>Cuvier pointed out the absence of a digestive -apparatus as a very general and distinctive characteristic -of plants. But the absence of a digestive -apparatus does not necessarily imply the absence of -digestion. The essential act of digestion is independent -of the infinite variety of the organs, just as a -reaction is independent of the form of the vessel in<span class="pagenum" id="Page_153">[Pg 153]</span> -which it takes place. It is, in fact, a chemical -transformation of an alimentary substance. This -transformation may be realized outside the organism, -<i>in vitro</i>, just as it can in the living being without -masticating organs, without an intestinal apparatus, -without glands, in a vessel placed in a stove, simply -by means of a few soluble ferments—pepsine, trypsine, -amylolytic diastases.</p> - -<p>All alimentary substances, whether taken from -without or borrowed from the reserves accumulated -in the internal stores of the organism, must undergo -preparation. This preparation is digestion. Digestion -is the prologue of nutrition. It is over when the -reparative substance, whether food or reserve-stuff, -is brought into a state enabling it to pass into the -blood, and to be utilized by the organism.</p> - -<p><i>The Identity of Categories of Foods in the Two -Kingdoms.</i>—Now the alimentary substances are the -same in the two kingdoms, and so is their digestive -preparation. Alimentary materials are of four -kinds: albuminoid, starchy, fatty, and sugary substances. -The animal takes them from without -(food properly so-called), or from within (reserve-stuff). -Man obtains starch, for instance, from different -farinaceous dishes. It may, however, equally well -be borrowed from the reserve of flour that we carry -within us in our liver, which is a veritable granary, -full of floury substance, glycogen. And so it is with -vegetables. The potato has its store of flour in its -tuber just as the animal has in its liver. The grain -which is about to germinate has it in reserve-stuff in -its cotyledons, or in its albumen. The bud which is -about to develop into a tree or a flower carries it at -its base.</p> - -<p><span class="pagenum" id="Page_154">[Pg 154]</span></p> - -<p>The same conclusions are true for another class -of substances, the sugars. They may be a food taken -from without, or a reserve deposited in the tissues. -The animal takes from without, in fruits for instance, -the ordinary sugar which pleases its taste. Beetroot, -when flowering and fructifying, draws this substance -from its roots in which stores have been amassed. -The sugar cane when running to seed takes the -sugar from the stores which it possesses in its cane. -Brewer’s yeast, the <i>saccharomyces cerevisiæ</i>, the agent -of alcoholic fermentation, finds this same substance in -the sugary juices favourable to its development.</p> - -<p>In the same way, identically fatty substances, -either in the form of food or of reserve-stuff, serve -for nutrition to animals and vegetables; and that is -again true of the substances of the fourth class, -albuminoids, identical in the two kingdoms, foods or -reserve-stuff, equally utilizable in both after digestion.</p> - -<p><i>Identity of the Digestive Agents and Mechanisms in -Plants and Animals.</i>—Now, the results of contemporary -research have been to establish a surprising -resemblance in the modifications experienced by these -foods, or reserve stuffs, in animals and plants; and -even resemblances in the agents which realize them, -and in the mechanisms by which they are performed. -There is a real unity. The flour accumulated in the -tuber of the potato is liquefied and digested on the -appearance of the buds or of the flower, just as the -starch of the liver or the alimentary flour is digested -by the animal. The fatty matter which is stored up -in the oleaginous grain is digested at the moment of -germination, just as the fat during a meal is digested -in the animal’s intestine. As the beetroot begins to -run to seed, the root gives up part of its store of<span class="pagenum" id="Page_155">[Pg 155]</span> -sugar, and this reserve stuff is distributed throughout -the stalk after having been digested, exactly as would -have been the case in the digestive canal of man.</p> - -<p>Vegetables, then, really digest. The four classes of -substances mentioned above are really digested in -order to pass from their actual form, a form unsuitable -for interstitial exchanges, to another form suitable for -nutrition. As there are four kinds of foods, so there -are four kinds of digestions, four kinds of ferment-producing -agents—amylolytic,<a id="FNanchor_14" href="#Footnote_14" class="fnanchor">[14]</a> proteolytic,<a id="FNanchor_15" href="#Footnote_15" class="fnanchor">[15]</a> saccharine, -and lipasic<a id="FNanchor_16" href="#Footnote_16" class="fnanchor">[16]</a> diastases, identical in the animal -and the plant. Identity of ferments implies identity -of digestions. Going down to the very basis of -things, the digestive act is nothing but the action of -this ferment. This is the crux of the whole question. -All else is only difference in scene, varying in the -means of execution and in the accessories. The -difference arises from the stage on which it takes -place, but the piece which is being played is the -same, and the actors are the same, and so is the -action of the play.</p> - -<p>This identity between animal and vegetable life is -found in the phenomena of respiration and of motility. -The limits of this book do not allow of our entering -into the details of facts. Besides, the facts are well -known, and may be found in any treatise on general -physiology. This science, therefore, enables us to -perceive the imposing unity of life in its essential -manifestations.</p> - -<p><span class="pagenum" id="Page_156">[Pg 156]</span></p> - -<p>The community of the phenomena of vitality in -animals and plants being thus placed beyond a doubt, -we must now discover the reason why. This reason -is to be found in their anatomical and in their -chemical unity. The fundamental phenomena are -common because the composition is common, and -because the universal anatomical basis, the cell, -possesses in all cases a sum total of identical -properties.</p> - -<p>If we appeal to physiology for the characteristics -common to living beings, it will generally give us the -following:—A structure or organization; a certain -chemical composition which is that of <i>living matter</i>; -a specific form; an evolution which in the earliest -stage occasions the being to grow and develop until -it is divided, and which in the highest stage includes -one or more evolutive cycles with growth, the adult -stage, senility, and death; a property of increase or -nutrition, with its consequence—namely, a relation of -material exchanges with the ambient medium;—and -finally, a property of reproduction. It is important -to pass them rapidly in review.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_157">[Pg 157]</span></p> - -<h3 class="nobreak" id="CHAPTER_II_3">CHAPTER II.<br /> - -<small>MORPHOLOGICAL UNITY OF LIVING BEINGS.</small></h3></div> - - -<p class="prel">§ 1. The cellular theory. First period: division of the organism—§ -2. Second period: division of the cell—Cytoplasm—The -nucleus—§ 3. Physical constitution of living matter—The -micellar theory—§ 4. Individuality of complex beings—The -law of the constitution of organisms.</p> - - - -<p>The first characteristic of the living beings is -<i>organization</i>. By that we mean that they have a -structure; that they are complex bodies formed of -smaller aliquot parts and grouped according to a -certain disposition. The most simple elementary -being is not yet homogeneous. It is heterogeneous. -It is organized. The least complex protoplasms, -those of bacteria, for example, still possess a -physical structure; Kunstler distinguishes in them -two non-miscible substances, presenting an alveolar -organization. Thus animals and plants present an -organization, and it is sensibly constant from one end -to the other of the scale of beings. There is a -<i>morphological unity</i>.</p> - - -<h4>§ 1. <span class="smcap">The Cellular Theory. First Period: -Division of the Organism into Cells.</span></h4> - - -<p><i>Cellular Theory. First Period.</i>—Morphological -unity results from the existence of a universal<span class="pagenum" id="Page_158">[Pg 158]</span> -anatomical basis, the <i>cell</i>. The cellular theory sums -up the teaching of general anatomy or histology.</p> - -<p>At the beginning of the nineteenth century anatomy -was following a routine dating from ancient times. -It divided animal and vegetable machines into units -in descending order, first into different forms of -apparatus (circulatory, respiratory, digestive, etc.); -then the apparatus into organs examined one by one, -figuring and describing each of them from every -point of view with scrupulous accuracy and untiring -patience. If we think of the duration of these -researches—the <i>Iliad</i>, as Malgaigne says, already -containing the elements of a very fine regional -anatomy—and especially of the powerful impulse -they received in the seventeenth and eighteenth -centuries, we shall understand the illusion of those -who, in the days of X. Bichat, could fancy that the -task of anatomy was almost ended.</p> - -<p>As a matter of fact this task was barely begun, for -nothing was known of the intimate structure of the -organs. X. Bichat accomplished a revolution when -he decomposed the living body into tissues. His -successors, advancing a step in the analysis, dissociated -the tissues into elements. These elements, -which one would have thought were infinitely varied, -were reduced in their turn to one common <i>prototype</i>, -the cell.</p> - -<p>The living body, disaggregated by the histologist, -resolves under the microscope into a dust, every grain -of which is a cell. A cell is an anatomical element -the constitution of which is the same from one part -to the other of the same being, and from one being to -another; and its dimensions, which are sensibly -constant throughout the whole of the living world,<span class="pagenum" id="Page_159">[Pg 159]</span> -have an average diameter of several thousandths of -a millimetre—<i>i.e.</i>, of several <i>microns</i>. This element, -the cell, is a real organ. It is smaller, no doubt, than -those described by the ancient anatomists, but it is not -less complex. Its complexity is only revealed later. -It is an organic unit. Its form varies from one -element to another. Its substance is a semi-fluid -mass, a mixture of different albuminoids. In the -mean value of its dimensions, so carefully measured—<i>exceptis -excipiendis</i>—we have a condition the significance -of which has not yet been discovered, but -which may be of great value in the explanation of its -peculiar activities.</p> - -<p>Such is the result to which have converged the researches -of the biologists who have examined plants -or the lower animals, as well as of the anatomists who -have been more especially occupied with the vertebrates -and with man. All their researches have -brought them to the same conclusion—the cellular -theory. Either living beings are composed of a single -cell—as is the case with the microscopic animals called -<i>protozoa</i>, and the microscopic vegetables called <i>protophytes</i>—or, -they are cellular complexes, <i>metazoa</i> or -<i>metaphytes</i>—that is to say, associations of these -microscopic organic units which are called cells.</p> - -<p><i>The Law of the Composition of Organisms.</i>—The -law of the composition of organisms was discovered -in 1838 by Schleiden and Schwann. From that time -up to 1875 it may be said that micrographers have -spent their time in examining every organ and every -tissue, muscular, glandular, conjunctive, nervous, etc., -and in showing that in spite of their varieties of -aspect and form, of the complexity of structures due -to cohesion and fusion, they all resolve into the com<span class="pagenum" id="Page_160">[Pg 160]</span>mon -element, the cell. Contemporary anatomists, -Koelliker, Max Schultze, and Ranvier, have thus -established the generality of the cellular constitution, -while zoologists and botanists confirm the same law -for all animals and vegetables, and exhibit them all -as either unicellular or multicellular.</p> - -<p><i>The Cellular Origin of Complex Beings.</i>—At the -same time embryogenic researches showed that all -beings spring from a corpuscle of the same type. -Going back in the history of their development to the -most remote period, we find a cell of very constant -constitution—namely, the <i>ovule</i>. This truth may be -expressed by changing a word in Harvey’s celebrated -aphorism—<i>omne vivum ex ovo</i>; we now say omne -<i>vivum e cellula</i>. The myriads of differentiated anatomical -elements whose association forms complex -beings are the posterity of a cell, of the <i>primordial -ovule</i>, unless they are the posterity of another equivalent -cell. The second task of histology in the latter -half of the nineteenth century consisted in following -up the filiation of each anatomical element from the -cell-egg to its state of complete development.</p> - -<p>The whole cellular theory is contained in the -two following statements, which establish the morphological -unity of living beings:—<i>Everything is a -cell, everything comes from an initial cell</i>; the cell -being defined as a mass of substance, protoplasm or -protoplasms, of an average diameter of a few microns.</p> - -<h4>§ 2. <span class="smcap">The Second Period: the Division Of -the Cell.</span></h4> - -<p><i>Second Period: Constitution of the Cell.</i>—This was, -however, only the first phase in the analytical study<span class="pagenum" id="Page_161">[Pg 161]</span> -of the living being. A second period began in -1873 with the researches of Strassburger, Bütschli, -Flemming, Kuppfer, Fromann, Heitzmann, Balbiani, -Guignard, Kunstler, etc. These observers in their -turn submitted this anatomical, this infinitely small -cellular microcosm, to the same penetrating dissection -their predecessors had applied to the whole organism. -They brought us down one degree lower into -the abyss of the infinitely small. And as Pascal, -losing himself in these wonders of the imperceptible, -saw in the body of the mite which is only a point, -“parts incomparably smaller, legs with joints, veins in -the legs, blood in the veins, humours in the blood, -drops in the humours, vapours in these drops,” so -contemporary biologists have shown in the epitome -of organism called a cell, an edifice which itself is -marvellously complex.</p> - -<p><i>The Cytoplasm.</i>—The observers named above revealed -to us the extreme complexity of this organic -unit. Their researches have shown us the structure -of the two parts of which it is composed—the cellular -protoplasm and the nucleus. They have determined -the part played by each in genetic multiplication. -They have shown that the protoplasm which forms the -body of the cell is not homogeneous, as was at first -supposed. The idea which was mooted later, that -this protoplasm was formed, to use Sachs’ words, of a -kind of “protoplasmic mud,”—<i>i.e.</i>, of a dust consisting -of grains and granules connected by a liquid,—is no -longer accurate. There is a much simpler view of the -case. According to Leydig and his pupils, we must -compare the protoplasm to a sponge in the meshes of -which is lodged a fluid, transparent, hyaline substance, -a kind of cellular juice, hyaloplasm. From the<span class="pagenum" id="Page_162">[Pg 162]</span> -chemical point of view this cellular juice is a mixture -of very different materials, albumens, globulins, carbohydrates, -and fats, elaborated by the cell itself. It is -a product of vital activity; it is not yet the seat of -this activity. The living matter has taken refuge in -the spongy tissue itself, in the <i>spongioplasm</i>.</p> - -<p>According to other histologists, the comparison of -protoplasm to a spongy mass does not give the -most exact idea, and, in particular, it does not furnish -the most general idea. It would be far better to say -that the protoplasm possesses the structure of foam -or lather. As was seen by Kunstler in 1880, a comparison -with some familiar objects gives the best idea. -Nothing could be more like protoplasm physically -than the culinary preparation known as <i>sauce mayonnaise</i>, -made with the aid of oil and a liquid with -which oil does not mix. Emulsions of this kind were -made artificially by Bütschli. He noted that these -preparations mimicked all the aspects of cellular -protoplasm. Thus, in the living cell there is a -mixture of two liquids, non-miscible and of unequal -fluidity. This mixture gives rise to the formation of -little cells. The more consistent substance forms -their supporting framework (Leydig’s spongioplasm), -while the other, which is more fluid, fills its interior -(hyaloplasm).</p> - -<p>However that may be, whether the primitive -organization of the cellular protoplasm be that of a -sponge, as is asserted by Leydig, or that of a <i>sauce -mayonnaise</i>, as is claimed by Bütschli and Kunstler, -the complexity does not rest there. Further recourse -must be made to analysis. Just as the tissue of a -sponge, when torn, shows the fibres which constitute -it, so the spongioplasm, the parietal substance, is<span class="pagenum" id="Page_163">[Pg 163]</span> -exhibited as formed of a tangle of fibrils, or better -still, of filaments or ribbons (in Greek, <i>mitome</i>), which -are called <i>chromatic filaments</i>, because they are deeply -stained when the cell is plunged into aniline dye. In -each of these filaments, the substance of which is -called chromatin, the devices of microscopic examination -enable us to discover a series of granulations like -beads on a string, the <i>microsomes</i> or bioblasts, connected -one with the other by a sort of cement, -Schwartz’s <i>linin</i>, which is a kind of nuclein.</p> - -<p>And let us add, to complete this summary of the -constitution of cellular protoplasm, that it presents, at -any rate at a certain moment, a remarkable organ, -the <i>centrosome</i>, which plays an important part in -cellular division. Its pre-existence is not certain. -Some writers make it issue from the nucleus. At the -moment of cellular division it appears like a compressed -mass of granulations, which may be deeply -stained. Around it is seen a clear unstainable zone, -called the attraction-sphere; and finally, beyond this -is a crown of striæ, which diverge like the rays of a -halo—<i>i.e.</i>, the <i>aster</i>. In conclusion, there are yet in -the cellular body three kinds of non-essential bodies: -the vacuoles, the leucites, and various inclusions. The -<i>vacuoles</i> are cavities, some inert, some contractile; the -<i>leucites</i> are organs for the manufacture of particular -substances; the <i>inclusions</i> are the manufactured products, -or wastes.</p> - -<p><i>The Nucleus</i>.—Every cell capable of living, -growing, and multiplying, possesses a <i>nucleus</i> of -constitution very analogous to the cellular mass -which surrounds it. The anatomical elements in -which no nucleus is found, such as the red globules -of blood in adult mammals, are bodies which are<span class="pagenum" id="Page_164">[Pg 164]</span> -certain, sooner or later, to disappear. There is therefore -no real cell without a nucleus, any more than -there is a nucleus without a cell. The exceptions to -this law are only apparent. Histologists have -examined them one by one, and have shown their -purely specious character. We may therefore lay -aside, subject to possible appeal from this decision, -organisms such as Haeckel’s <i>monera</i> and the problem -of finding out if bacteria really have a nucleus. The -very great, if not the absolute generality of the -nuclear body, must be admitted.</p> - -<p>It hence follows that there is a nuclear protoplasm -and a nuclear juice, just as we have seen that there is a -protoplasm and a cellular juice. What was just said of -the one may now be repeated of the other, and perhaps -with even more emphasis. The nuclear protoplasm -is a filamentary mass sometimes formed of a single -mitome or cord, folded over on itself and capable of -being unrolled. The mitome in its turn is a string -of microsomes united by the cement of the linin. -These are the same constituent elements as before, -and the language of science distinguishes them one -from the other by a prefix to their name of the words -<i>cyto</i> or <i>karyo</i>, which in Greek signify cell and nucleus, -according as they belong to one or the other of these -organs. These are mere matters of nomenclature, -but we know that in the descriptive sciences such -matters are not of minor importance.</p> - -<p>We have just indicated that in a state of repose,—that -is to say, under ordinary conditions,—the structure -of a nucleus reproduces clearly the structure of the -cellular protoplasm which surrounds it. The nuclear -essence is best separated from the spongioplasm. -It takes more clearly the form of a filamentary<span class="pagenum" id="Page_165">[Pg 165]</span> -thread, and the filaments themselves (mitome) show -very thick chromatic granulations, or microsomes, -connected by the linin.</p> - -<p>At the moment of reproduction of the cell these -granulations blend into a stainable sheath which -surrounds the filaments, and the latter dispose themselves -so as to form a single thread. This chromatic -filament, which has now become a single thread, is -shortened as it thickens (<i>spireme</i>); it is then cut into -segments, twelve or twenty-four in the case of animals -and a larger number in the case of plants. These -are <i>chromosomes</i>, or <i>nuclear segments</i>, or <i>chromatic</i> -loops. Their part is a very important one. They -are constant in number and permanent during the -whole of the life of the cell. Let us add that the -nucleus still contains accessory elements (nucleoli).</p> - -<p><i>The Rôle of the Nucleus</i>.—Experiment has shown -that the nucleus presides over the nutrition, the -growth, and the conservation of the cell. If, following -the example of Balbiani, Gruber, Nussbaum, and -W. Roux of Leipzig, we cut into two a cell without -injuring the nucleus, the fragment which is denuded -of the nucleus continues to perform its functions for -some time in the ordinary manner, and in some -measure in virtue of its former impulse. It then -declines and dies. On the contrary, the fragment -provided with the nucleus repairs its wound, is -reconstituted and continues to live. Thus the nucleus -takes a very remarkable part in the reproduction of -the cell, but it is still a matter of uncertainty whether -its rôle is here subordinated to that of the cellular -body, or if it is pre-eminent. However that may be, -it follows from this experiment that the nucleus -presents all the characteristics of a vigorous vitality,<span class="pagenum" id="Page_166">[Pg 166]</span> -and that it is in its protoplasm that the chemists -should be able to find the compounds, the special -albuminoids, which, <i>par excellence</i>, form living matter.</p> - - -<h4>§ 3. <span class="smcap">The Physical Constitution of Living -Matter. The Micellar Theory.</span></h4> - -<p><i>Physical Constitution of Living Matter</i>.—Microscopic -examination does not take us much farther. -The microscope, with the strongest magnification -of which it is capable at present, shows us nothing -beyond these links of aligned microsomes forming -the species of protoplasmic thread or mitome, whose -cellular body is a confused tangle or a very tangled -ball. It is not probable that direct sight can penetrate -much farther than this. No doubt the microscope, -which has been so vastly improved, is capable -of still further improvement. But these improvements -are not indefinite. We have already reached -a linear magnification of 2000, and theory tells us -that a magnification of 4000 is the limit which cannot -be passed. The penetrating power of the instrument -is therefore near its culminating point. It has already -given almost all that we have a right to expect -from it.</p> - -<p>We must, however, penetrate beyond this microscopic -structure at which the sense of sight has been -arrested. How is this to be done? When observation -is arrested, hypothesis takes its place. Here -there are two kinds of hypotheses, the one purely -anatomical, the other physical. Anatomically, beyond -the visible microsomes there have been imagined -invisible hyper-microscopic corpuscles, the plastidules<span class="pagenum" id="Page_167">[Pg 167]</span> -of Haeckel, the idioblasts of Hertwig, the pangenes of -de Vries, the plasomes of Wiesner, the gemmules of -Darwin, and the biophores of Weismann.</p> - -<p>Biologists who have not got all that they hoped -from microscopic structure are therefore thrown back -on hyper-microscopic structure.</p> - -<p>It is very remarkable that all this profound knowledge -of structure has been so sterile from the point -of view of the knowledge of cellular functional activity. -All that is known of the life of the cell has been -revealed by experiment. Nothing has resulted from -microscopic observation but ideas as to configuration. -When it is a question of giving or imagining an -explanation of vital facts, of heredity, etc., biologists -unable to supply anything beyond the details of -structure revealed by anatomy have had recourse to -hypothetical elements, gemmules, pangenes, biophores, -and different kinds of determinants.</p> - -<p>Anatomy never has explained and never will explain -anything. “Happy physicists!” wrote Loeb, -“in never having known the method of research by -sections and stainings! What would have happened -if by chance a steam engine had fallen into the hands -of a histological physicist? How many thousands of -sections differently stained and unstained, how many -drawings, how many figures, would have been produced -before they knew for certain that the machine -is an engine, and that it is used for transforming -heat into motion!”</p> - -<p>The study of physical properties, continued on -rational hypotheses, has also thrown some light -on the possible constitution of living matter. The -gap between microscopical structure and molecular or -chemical structure has thus been filled.</p> - -<p><span class="pagenum" id="Page_168">[Pg 168]</span></p> - -<p>The consideration of the properties of <i>turgescence</i> -and of <i>swelling</i>, which very generally belong to -organized tissues, and therefore to the organic -substance of protoplasm, has enabled us to obtain -some idea of its ultra-microscopic constitution. If -we wet a piece of sugar or a morsel of salt, before -they are dissolved they absorb and imbibe the water -without sensibly increasing their volume. It is quite -otherwise with a tissue (<i>i.e.</i>, with a protoplasm) -when weakened in water as a preliminary. The -tissue, plunged into the liquid, absorbs it, swells, and -often grows considerably. And this water does not -lodge in the gaps, in pre-existing lacunar spaces, for -organic matter presents no gaps of this kind. It -does not resemble a porous mass with capillary -canals, such as sandstone, tempered mortar, clay, or -refined sugar. The molecules of water interpose -between and separate the organic molecules, thus -increasing by a sort of intussusception the intervals -separating the one from the other—molecular intervals -escaping the senses, as do the molecules themselves -because they are of the same order of magnitude.</p> - -<p><i>Micellar Theory.</i>—While pondering over this -phenomenon, an eminent physiologist, Nägeli, was -led in 1877 to propose his <i>micellar theory</i>. Micellæ -are groups of molecules in the sense in which -physicists and chemists use the word. They are -molecular structures with a configuration. They -rapidly absorb water and are capable of fixing a -more or less thick and adherent layer of it to their -surface. In a word, they are aggregates of organic -matter and water.</p> - -<p>There is therefore every reason for believing that -the <i>microsomes</i> of spongy protoplasm, the physical<span class="pagenum" id="Page_169">[Pg 169]</span> -support or basis of cellular life, are <i>groups of micellæ</i> -formed of albuminoid substances and water. These -clustered forms, these micellæ, are not absolutely -peculiar to organized matter. Pfeffer, the learned -botanist, has pointed them out under another name, -<i>tagmata</i>, in the membranes of chemical precipitates.</p> - -<p>Beyond this limit analysis finds nothing but the -chemical molecule and the atom. So that if we -wish to reconstruct the hierarchy of the materials of -constitution of the protoplasm in order of ascending -complexity, we shall find at the foundation the atom or -atoms of simple bodies. They are principally carbon, -hydrogen, oxygen, nitrogen, the elements of all -organic compounds, to which may be added sulphur -and phosphorus. At the head we have the albuminoid -molecule, or the albuminoid molecules, -aggregates of the preceding atoms. In the third -stage the micellæ or tagmata, aggregates of albuminoids -and water, are still too small to be observed -by the senses. They unite in their turn to form the -microsomes, the first elements visible to the microscope. -The microsomes, cemented by linin, form the -filaments or links which are called mitomes. The -living protoplasm is therefore nothing but a chain, or -tangled skein, or a spongy skeleton formed by its -filaments.</p> - -<p>Such is the typical constitution of living matter -according to microscopic observation, supplemented by -a perfectly reasonable hypothesis, which is, so to speak, -only a translation of one of its most evident physical -properties. This relatively simple scheme has become -a complex scheme in the hands of later biologists. -On the micellar hypothesis, which seems almost -inevitable in its character, new hypotheses have been<span class="pagenum" id="Page_170">[Pg 170]</span> -grafted, merely for the sake of convenience. Hence, -we are led farther and farther from the real truth, -and this is why, in order to explain the phenomena -of heredity, we find ourselves compelled to intercalate -hypothetical elements between micellæ and -the microsome in the higher hierarchy quoted above—gemmules, -pangenes, plasomes, which are only mental -pictures or simple images to represent them.</p> - - -<h4>§ 4. <span class="smcap">The Individuality of Complex Beings. -Law of the Constitution of Organisms.</span></h4> - - -<p><i>Individuality of Complex Beings.</i>—From the cellular -doctrine follows a remarkably suggestive conception -of living beings. The metazoa and the metaphytes—that -is to say, the multicellular living beings which -may be seen with the eyes and do not require the -microscope to reveal them—are an assemblage of -anatomical elements and the posterity of a cell. -The animal or the plant, instead of being an -individual unity, is a “multitude,” a term which is -used by Goëthe himself when pondering, in 1807, over -the doctrine taught by Bichat; or, according to the -equally correct expression of Hegel, it is a “nation”; -it springs from a common cellular ancestor, just as -the Jewish people sprang from the loins of Abraham.</p> - -<p>We now picture to ourselves the complex living -being, animal or plant, with its configuration which -distinguishes it from every other being, just as a -populous city is distinguished by a thousand -characteristics from its neighbour. The elements -of this city are independent and autonomous for the -same reason as the anatomical elements of the<span class="pagenum" id="Page_171">[Pg 171]</span> -organism. Both have in themselves the means of -life, which they neither borrow nor take from their -neighbours nor from the whole. All these inhabitants -live in the same way, are nourished and breathe in -the same manner, all possessing the same general -faculties, those of man; but each has besides, his -profession, his trade, his aptitudes, his talents, by -which he contributes to social life, and by which in -his turn he depends on it. Professional men, the -mason, the baker, the butcher, the manufacturer, the -artist, carry out different tasks and furnish different -products, the more varied, the more numerous and -the more differentiated, in proportion as the social -state has reached a higher degree of perfection. The -living being, animal or plant, is a city of this kind.</p> - -<p><i>Law of the Constitution of Organisms.</i>—Such is -the complex animal. It is organized like the city. -But the higher law of this city is that the conditions -of the elementary or individual life of all the anatomical -citizens are respected, the conditions being -the same for all. Food, air, and light must be -brought everywhere to each sedentary element; the -waste must be carried off in discharges which will -free the whole from the inconvenience or the danger -of such debris; and that is why we have the different -forms of apparatus in the circulatory, respiratory, -and excretory economy. The organization of the -whole is therefore dominated by the necessities of -cellular life. This is expressed in <i>the law of the constitution -of organisms</i> formulated by Claude Bernard. -The organic edifice is made up of apparatus and -organs, which furnish to each anatomical element -the necessary conditions and materials for the maintenance -of life and the exercise of its activity. We<span class="pagenum" id="Page_172">[Pg 172]</span> -now understand what is the life, and at the same -time what is the death, of a complex being. The -life of the complex animal, of the metazoon, is of two -degrees; at the foundation, the activity proper to -each cell, <i>elementary life</i>, cellular life; above, the -forms of activity resulting from the association of the -cells, <i>the life of the whole</i>, the sum or rather the -complex of elementary partial lives. There is a -solidarity between them produced by the nervous -system, by the community of the general circulatory, -respiratory apparatus, etc., and by the free communication -and mixture of the liquids which constitute -the media of culture for each cell. We shall -have an opportunity of recurring to current ideas as -to the morphological constitution of organisms.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_173">[Pg 173]</span></p> - -<h3 class="nobreak" id="CHAPTER_III_3">CHAPTER III.<br /> - -<small>THE CHEMICAL UNITY OF LIVING BEINGS.</small></h3></div> - - -<p class="prel">The varieties and essential unity of the protoplasm—Its -affinity for oxygen—The chemical composition of protoplasm—Its -characteristic substances.—§ 1. The different -categories of albuminoid substances—Nucleo-proteids—Albumins -and histones—Nucleins.—§ 2. Constitution of -nucleins.—§ 3. Constitution of histones and albumins—Schultzenberger’s -analysis of albumin—Kossol’s analysis—The -hexonic nucleus.</p> - - -<p>The chemical unity of living beings corresponds to -their morphological unity.</p> - -<p><i>The Varieties and Essential Unity of the Protoplasm.</i>—One -essential feature of the living being is -that it is composed of matter peculiar to it, which is -called <i>living matter</i>, or <i>protoplasm</i>. But this is a -somewhat incorrect way of expressing the facts. -There is no unique living matter, no single protoplasm; -their number is infinite, there are as many as -there are distinct individuals. However like one -man may be to another, we are compelled to admit -that they differ according to the substance of which -they are constituted. That of the first offers a certain -characteristic personal to the first, and found in all -his anatomical elements; similarly for the second. -With Le Dantec we shall say that the chemical -substance of Primus is not only of the substance of -man, but in all parts of his body and in all his con<span class="pagenum" id="Page_174">[Pg 174]</span>stituent -cells it is the exclusive substance of Primus; -and, in the same way, the living matter of another -individual Secundus will carry everywhere his personal -impress, which differs from that of Primus.</p> - -<p>But it is none the less true that this absolute -specificity is based with certainty only on differences -which from the chemical point of view are exceedingly -slight. All these protoplasms have a very analogous -composition. And, if we regard as negligible the -smallest individual, specific, generic, or ordinal variations -we may then speak in a general manner of -<i>protoplasm</i> or <i>living matter</i>.</p> - -<p>Experiment shows us, in fact, that the real living -substance—apart from the products it manufactures -and can retain or reject—is in every cell tolerably -similar to itself. The fundamental chemical resemblance -of all protoplasms is certain, and thus -we may speak of their typical composition. We -may sum up the work of physiological chemistry for -the last three quarters of a century by affirming that -it has established the chemical unity of all living -beings—that is to say, a very notable analogy in the -composition of their protoplasm.</p> - -<p>This living matter is essentially a mixture of the -proteid or albuminoid substances, to which may be -added other categories of immediate principles, such -as carbohydrates and fatty matters. But the latter -are of secondary importance. The essential element -is the proteid substance. The most skilful chemists -have tried for more than half a century to discover -its composition. Only during the last few years—thanks -to the researches of Kossel, the German -chemist, following on those of Schultzenberger and -Miescher—we are beginning to know the outer walls<span class="pagenum" id="Page_175">[Pg 175]</span> -or the framework of the albuminoid molecule; in -other words, its chemical nucleus.</p> - -<p><i>Physical Characters of Protoplasm.</i>—About 1860 -Ch. Robin thought that he had defined living matter -sufficiently—or, at least, as perfectly as could be -expected at that time—by attributing to it three -physical characteristics. They were:—Absence of -homogeneity, molecular symmetry, and the association -of three orders of immediate principles—albuminoids, -carbohydrates and fats. These characteristics assist, -but do not suffice, to define the organization.</p> - -<p>No doubt the characteristics must be completed by -the addition of a certain number of more subtle -physical features.</p> - -<p>One of them refers to the structure of protoplasm -as revealed by the microscope. Throughout the -whole of the living kingdom, from the bacteria studied -by Kunstler and Busquet to the most complicated -protozoa, protoplasmic matter presents the same -constitution, and in consequence, this structure of -the protoplasm must be considered as one of its -distinctive characters. It is not homogeneous; it -is not the last term of the visible organization: it is -itself organized. Experiment shows that it does not -resist breaking up or crushing. Mutilations cause -it to lose its properties. As for the kind of structure -that it presents, it may be expressed by saying that it -is that of a foamy emulsion.</p> - -<p>We saw above that our knowledge as to the physical -condition of protoplasm has been completed by the -theories of Bütschli’s micellæ or Pfeffer’s tagmata.</p> - -<p><i>Properties of the Protoplasm. Its Affinity for -Oxygen.</i>—From the chemical point of view, living -matter presents a very remarkable property—namely,<span class="pagenum" id="Page_176">[Pg 176]</span> -a great affinity for oxygen. It absorbs it so greedily -that the gas cannot remain in a free state in its -neighbourhood. Living protoplasm, therefore, exercises -a reducing power. But it does not absorb -oxygen in this way for its own advantage; oxygen -is not absorbed, as was supposed thirty years ago, to -supply fuel wherewith to burn the protoplasm. The -products are not those of its oxidation, of its own -disintegration. They are the products of combustion -of the reserve-stuff which is incorporated in it. -These substances have been supplied to it from -without, like the oxygen itself, with the blood. This -was proved by G. Pflüger in 1872 to 1876. The -protoplasm is only the focus, the scene, or the -factor of combustion. It is not its victim, it does -not itself furnish the fuel. It works like the chemist, -who obtains a reaction with the substances that are -given to him.</p> - -<p>As for the reducing power of protoplasm, A. -Gautier in 1881 and Ehrlich in 1890 have given fresh -proofs. A. Gautier in particular has insisted that the -phenomena of combustion take place, so to speak, -outside the cell, and at the expense of the products -which surround it; while on the contrary the really -active and living parts of the nucleus and of the -cellular body, work protected by the oxygen, as in the -case of anaerobic microbes.</p> - -<p>This result is of great importance. Burdon Sanderson, -the late learned professor of physiology at the -University of Oxford, has not hesitated to compare -it to the discovery of respiratory combustion by -Lavoisier. There is no doubt some exaggeration in -the comparison; but there is, on the other hand, no -less exaggeration in supposing that it is not of great<span class="pagenum" id="Page_177">[Pg 177]</span> -importance. We may no longer in these days speak -without reservation of the vital vortex of Cuvier, and -of the incessant twofold movement of assimilation -and dissimilation which is ever destroying living -matter and building it up again. In reality, the -living protoplasm varies very little; it only undergoes -oscillations of very slight extent; it is the -materials, the reserve stuff on which it operates, which -are subject to continual transformations.</p> - -<p><i>Chemical Composition of Protoplasm.</i>—One of the -the three characters attributed by Ch. Robin to living -matter was its chemical composition, of which little -was known in his time. He insisted on the constant -presence in the living elements of three orders of -immediate principles—proteid substances, carbohydrates, -and fatty bodies. In reality the proteid -substances, or albuminoids, alone are characteristic. -The two other groups, carbohydrates and fatty bodies, -are rather the signs and the products of the vital -activity, than constituents of the matter on which it is -exercised.</p> - -<p>It is therefore on the knowledge of the proteid -substances that all the sagacity of biological chemists -has been exercised. Their efforts for thirty years, -and particularly in the last few years, have not been -barren; they enable us to give a first rough sketch of -the constitution of these substances.</p> - - -<h4>§ 1. <span class="smcap">The Characteristic Substances of the -Protoplasm. The Nucleo-Proteids.</span></h4> - - -<p><i>The Different Categories of Albuminoid Substances.</i>—Albuminoid -or proteid substances are extremely -complex compounds, much more so than any of those<span class="pagenum" id="Page_178">[Pg 178]</span> -which are being constantly studied by the chemist. -They also are to be found in great variety. It has -been difficult to separate them one from the other, to -characterize them rigorously, or, in other words, to -classify them. However, it has been done now, and -we distinguish three classes which are differentiated -at once from the physiological and from the chemical -points of view. The first comprises the complete or -typical albuminoids. They are the <i>proteids</i> or <i>nucleo-albuminoids</i>. -They are to be found in the most active -and most living parts of the protoplasm, and therefore -in the spongioplasm of the cell and around the -nucleus. The second group is formed of <i>albumins</i> -and <i>globulins</i>, compounds already simpler, fragments -derived from the destruction of the preceding, into -which they enter as constituent elements. In the -isolated state they do not belong to the really living -protoplasm; they exist in the cellular juice, in the -interstitial and circulating liquids in the blood and in -the lymph. The third category comprises real but -incomplete albuminoids. They are to be found in -the portions of the economy which have a specialized -or attenuated life, and are destined to serve as a -support to the more active elements—<i>i.e.</i>, they contribute -to the building up of the bony, cartilaginous, -conjunctive, elastic tissues. They are called <i>albumoids</i>. -It is naturally the first group, that of the -proteids—<i>i.e.</i>, of the complete and characteristic compounds -of the living substance—upon which the -attention of the physiologists must be fixed. It is -only quite recently that the clear definition of these -substances has been given, and proteid compounds -detected in the confused mass.</p> - -<p><i>The Nucleo-proteids.</i>—This progress in the char<span class="pagenum" id="Page_179">[Pg 179]</span>acterization -and specification of the proteids required -in the first place a knowledge of two particular compounds, -the <i>nucleins</i> and the <i>histones</i>. This did not -become possible until after the researches of Miescher -and Kossel on the nucleins, which went on from 1874 -to 1892, and those of Lilienfeld and d’Yvor Bang on -the histones, from 1893 to 1899. The complete -albuminoids are constituted by the combination of -two kinds of substances—albumins or histones on the -one hand, and nucleins on the other. By combining -solutions of albumins or histones with solutions of -nuclein, the synthesis of the proteid is effected. The -study of the properties and characteristics of these -nucleo-albumins and nucleo-histones is going on at -the present moment. It is being carried out with -much method and with wonderful patience by the -German school.</p> - -<p>All the proteids contain phosphorus in addition to -the five chemical elements, carbon, oxygen, hydrogen, -nitrogen, and sulphur, which are common to the -other albuminoids. Another interesting feature in -their history is that the action of the gastric juice -divides them into their two constituents:—the nuclein, -which is deposited and resists the destructive action -of the digestive liquid, and the albumin or histone, -which on the contrary experiences this action with -the usual consequences. Thus the gastric juice -furnishes a process which is very simple and very -convenient in the analysis of the proteids.</p> - -<p><i>Localization of the Nucleo-Proteids.</i>—What we said -before as to the important physiological rôle of the -cellular nucleus may arouse the expectation that in it -will be found the living matter which is chemically -the most differentiated, the albuminoids of highest<span class="pagenum" id="Page_180">[Pg 180]</span> -rank—<i>i.e.</i>, the nucleo-proteids and their constituents. -Not that they would not be found in the protoplasm -of the rest of the cell, but there is certainly a risk -that they would be less concentrated there and more -blended with accessory products; they are there connected -with much more secondary vital functions. -This conclusion inspired the early researches of Professor -Miescher, of Basle, in 1874, and, twenty years -later, those of Professor Kossel, one of the most -eminent physiological chemists in Germany.</p> - -<p>In fact, these compounds have been found in all -tissues which are rich in cellular elements with well-developed -nuclei. The white globules of the blood -furnished to Lilienfeld the first nucleo-histone ever -isolated. The red globules themselves, when they -possess a nucleus, which is the case in birds and -reptiles as well as in the embryo of mammals, contain -a nucleo-proteid which was easily isolated by Plosz and -Kossel. Hammarsten, the Swedish chemist, who has -acquired a great reputation from his researches in -other domains of biological chemistry, prepared the -nucleo-proteids of the pancreas in 1893. They have -been obtained from the liver, from the thyroid -gland (Ostwald), from brewers’ yeast (Kossel), from -mushrooms, and from barley (Petit). They have -been detected in starchy bodies and in bacteria -(Galeotti).</p> - - -<h4>§ 2. <span class="smcap">Constitution of Nucleins.</span></h4> - - -<p><i>Constitution of Nucleins.</i>—Our path is already -marked out if we wish to penetrate farther into the -constitution of these proteids, which are the imme<span class="pagenum" id="Page_181">[Pg 181]</span>diate -principles highest in complexity among those -which form the living protoplasm. We must analyze -the two components, the albumins and the histones on -the one hand, and the nucleins on the other. As for -the nucleins, this has already been done, or very -nearly so.</p> - -<p>Kossel, in fact, decomposed the nuclein by a series -of very carefully arranged operations, and has reduced -it step by step to its crystallizable organic radicals. -At each stage that we descend in the scale of -simplification a body appears which is more acid and -more rich in phosphorus. At the third stage we -come to phosphoric acid itself. The first operation -divides the nuclein into two substances: the new -albumin and nucleinic acid. After separating these -elements they can be reunited: a solution of albumin -with a solution of nucleinic acid reconstitutes the -nuclein. A second operation separates the nucleinic -acid in its turn into three parts. One is a body of -the nature of the sugars—<i>i.e.</i>, a carbohydrate. The -appearance of a sugar in this portion of the molecule -of nucleinic acid is an interesting fact and fertile in -results. The second part is constituted by a mixture -of nitrogenous bodies, well known in organic chemistry -under the name of <i>xanthic bases</i> (xanthin, hypoxanthin, -guanin, and adenin). The third part is a -very acid body and full of phosphorus—thymic acid. -If in a third and last operation the thymic acid is -analyzed, it is finally separated into phosphoric acid -and into thymene, a crystallizable base, and thus we -are brought back to the physical world, for all these -bodies incontestably belong to it.</p> - -<p><span class="pagenum" id="Page_182">[Pg 182]</span></p> - - -<h4>§ 3. <span class="smcap">The Constitution of Histones and -Albumins.</span></h4> - - -<p><i>Constitution of Histones.</i>—But we are only half-way -through our task. We are acquainted in its origin -with one of the genealogical branches of the proteid, -the nucleinic branch. We must also learn something -of the other branch, the albumin or histone branch. -But on this side the problem assumes a character of -difficulty and complexity which is admirably adapted -to discourage the most untiring patience.</p> - -<p>The analysis of albumin for a long time baulked -the chemist “Here,” said Danilewsky, “we come to -a closed door which resists all our efforts.” We know -how vastly interesting what is taking place on the -other side must be, but we cannot get there. We get -a mere glimpse through the cracks or chinks which -we have been able to make.</p> - -<p>This analysis of albuminous matter at first requires -great precautions. The chemist finds himself in the -presence of architecture of a very subtle kind. The -molecule of albumin is a complex edifice which has -used up several thousand atoms. To perceive the -plan and structure, it must be dismantled and -separated into parts which are neither too large nor -too small. Such careful demolition is difficult. -Processes too rough or too violent will reduce the -whole to the tiniest of fragments. It is a statue -which may be reduced to dust, instead of being -separated into recognizable fragments, easily fitted in -place along their fractured faces.</p> - -<p><i>Analysis of Albumin by Schützenberger.</i>—Schützenberger, -a chemist of great merit, attempted (about<span class="pagenum" id="Page_183">[Pg 183]</span> -1875) this thankless task. Others before him had -experimented in various ways. Two Austrian -scientists, Hlasitwetz and Habermann, in 1873, and -a little later Drechsel in 1892, had used concentrated -hydrochloric acid to break down albumin. -They also employed bromine for the same purpose. -More recently Fuerth had used nitric acid with a -similar object. Schützenberger tried another way. -The battering ram which he used against the edifice -of albumin was a concentrated alkali, baryta. He -warmed the white of an egg with barium hydrate -in a closed vessel at a temperature of 200°. The -albumin of egg then divides into a certain number of -simpler groups. The difficulty is to isolate and to -recognize each part in this mass of the materials of -demolition. That can be done by the aid of the -processes of direct analysis. By mentally combining -these different fragments, the original building is -reconstructed. This method of demolition is certainly -too rough and violent. Schützenberger’s operation -gives us very fine fragments—small molecules of free -hydrogen, of ammonia, of carbonic, acetic, and oxalic, -acids which reveal extreme pulverization. These -products represent about a quarter of the total mass. -The other three-quarters are formed of larger fragments, -the examination of which is most instructive. -They belong to four groups. The first comprises five -or six bodies, amido-acids or <i>leucins</i>. It proves the -existence in the molecule of albumin of compounds of -the series of fats—<i>i.e.</i>, arranged in an open chain. -The second group is formed by tyrosin and kindred -products—<i>i.e.</i>, by the bodies of the aromatic series, -which force us to acknowledge the presence in the -molecule of albumin of a benzene nucleus. The third<span class="pagenum" id="Page_184">[Pg 184]</span> -group forms around the nucleus known to chemists -under the name of pyrrol. The fourth comprises -bodies such as the glucoproteins, connected with the -sugars, or carbohydrates.</p> - -<p>Does the fact that the molecule of albumin is -destroyed in producing these compounds raise the -question as to whether it implies the idea that in -reality they pre-exist in it? Chemists are rather -inclined to admit this. However, the conclusion does -not appear to be permissible. Duclaux considers it -doubtful. It is not certain that all these fragmentary -bodies pre-exist in reality, and it is no more certain -that a simple bringing of them together represents -the primitive edifice. Materials of demolition from a -house that has been pulled down give no idea of its -natural architectural character. There is only one -way of justifying the hypothesis, and that is to reconstitute -the original molecule of albumin by bringing -the fragments together. We have not got to that -stage yet. The era of syntheses of such complexity -is more or less near, but it has certainly not yet -begun.</p> - -<p>Moreover, it is not correct to say that the simple -juxtaposition of the surfaces of fracture will reproduce -the initial body. The fragments, so far as analysis -has obtained them, are not absolutely what they might -have been in the original structure. There they -adhered the one to the other, not only by the mere -contact of their surfaces of fracture, as is supposed, -but in a slightly more complex manner. The fragments -of the molecule are joined by bonds. We can -picture them to ourselves by supposing these bonds -to be like hooks. The hooks, which could only be -broken by violence, are called by the chemists<span class="pagenum" id="Page_185">[Pg 185]</span> -<i>satisfied atomicities</i>. These atomicities, set free by -the breaking up, cannot remain in this condition; -they must be satisfied anew. The hook tries to attach -itself. In Schützenberger’s experiment the addition -of water provides for this necessity. A molecule of -water (H<sub>2</sub>O) splits into two, the hydrogen (H) on the -one side and the hydroxyl (OH) on the other. These -two elements cling to the liberated bonds of the -fragments of the molecule of albumin, and thus -the bodies were found complete. Schützenberger’s -experiment was too violent, too radical, and it gave -too large a number of fragments, with their free hooks -and atomicities unsatisfied, for rather a large proportion -of the water added disappeared during the -experiment. In one case this quantity was as much -as 17 grammes per 100 grammes of albumin. The -molecules of this water were employed in the -reparation of the incomplete fragmentary molecules -of the albumin.</p> - -<p>It follows that Schützenberger’s experiment gave -too large a number of very small pieces corresponding -to far too great a pulverization. The very small fragments -are the molecules of acids such as acetic acid, -oxalic acid, carbonic acid, molecules of ammonia, -and even of hydrogen, which we know we are setting -free.</p> - -<p>But, apart from these products which represent a -quarter of the molecule of albumin submitted to -analysis, the other three quarters represent larger -fragments which may be considered as the real -constituents of the building. Thus we find four -kinds of groups which may be accepted as natural. -The first of these groups is that of the leucins or -amido-acids. It proves the existence in the molecule<span class="pagenum" id="Page_186">[Pg 186]</span> -of albumin of compounds of the fatty series. There -is also an aromatic group—a pyridine group—and a -group belonging to the category of sugars. Imagine -a certain grouping of these four series. This would -be the nucleus of the molecule of albumin. If we -graft on to this nucleus, on to this framework as it -were, so many annexes, or lateral chains, the building -will be loaded with embellishments; it will have -been made unstable and <i>ipso facto</i> appropriate for the -part that it plays in the incessant transformations -of the organism.</p> - -<p><i>Kossel’s Analysis. Hexonic Nucleus.</i>—Kossel has -approached the problem in another fashion. He -did not attempt to attack the albumin of the egg. -This body is, in fact, a heterogeneous mixture as -complex as the needs of the embryo of which it forms -the food. Kossel tried a physiologically simpler -albuminoid. He got it from an anatomical element -having no nutritive rôle, of a very elementary -organization and physiological functional activity, -and yet one of energetic vitality—the male generating -cell. Instead of the hen’s egg he therefore analyzed -the milt of fish, and, in the first place, of salmon. As -was to be expected from what has been said of the -proteids, this living matter gives a combination of -the nuclein, already known, with an albumin. The -latter is abundant, forming a quarter of the total -mass. Its reaction is strongly alkaline, which is the -general characteristic of the variety of albumin known -by the name of histones. Miescher, the learned -chemist of Basle, who had noticed this basic albumin -when working on the Rhine salmon, gave it the name -of protamin. This is the substance submitted by -Kossel to analysis in preference to the albumin of<span class="pagenum" id="Page_187">[Pg 187]</span> -egg, so dear to the chemists who had preceded him. -The disintegration of this molecule, instead of giving -the series of bodies obtained by Schützenberger, -gave but one, a real chemical base, <i>arginin</i>. At the -first trial the albumin examined was reduced to a -simple crystallizable element. The conclusion was -obvious. The protamin of salmon is the simplest of -albumins. To form this elementary proteid substance -a hexonic base with water is all that is required.</p> - -<p>Continuing on these lines other male generating -cells were examined and a series of protamines constructed -on the same type was found, and these -albuminous bodies proved to be formed of a base or -mixture of analogous hexonic bases: arginin, histidin, -and lysin—all bodies closely akin in their properties -and entirely belonging to the physical world.</p> - -<p>Once aware of the existence of this fundamental -nucleus, chemists found it in the more complex -albumins where it had been missed. It was found in -the albumin of egg hidden under the mass of other -groups. It was recognized in all animal or vegetable -albumins. The nuclei of Schützenberger may be -missing. Hexonic bases are the constant and -universal element of all varieties of albumins. They -prevail in the chemical nucleus of the albuminous -molecule, and perhaps as is suggested by Kossel, -they may form it exclusively. All the other elements -are superadded and accessory. The essential type of -this molecular edifice, sought for so long, is known at -last.</p> - -<p><i>Conclusion.</i>—To sum up, the chemical unity of -living beings is expressed by saying that living -matter, protoplasm, is a mixture or a complex of -proteid substances with an hexonic nucleus.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_188">[Pg 188]</span></p> - -<h3 class="nobreak" id="CHAPTER_IV_3">CHAPTER IV.<br /> - -<small>THE TWOFOLD CONDITIONING OF VITAL -PHENOMENA. IRRITABILITY.</small></h3></div> - - -<p class="prel">Appearance of internal activity of the living being—Vital -phenomena regarded as a reaction of the ambient world.—§ -1. Extrinsic conditions—The optimum law.—§ 2. Intrinsic -conditions—The structure of organs and apparatus—How -experiment attacks the phenomena of life. Generalization -of the law of inertia—Irritability.</p> - - -<p><i>Instability. Mutability. The Appearance of Internal -Activity of the Living Being.</i>—One of the most -remarkable characteristics of the living being is its -instability. It is in a state of continual change. The -simplest of the elementary beings, the plastid, grows -and goes on growing and becoming more complex, -until it reaches a stage at which it divides, and thus -rejuvenated it commences the upward march which -leads it once again to the same segmentation. Its -evolution is thus betrayed by its growth, by the -variations of form which correspond to it, and by -its division.</p> - -<p>If it be a question of beings higher in organization -than the cellular element the evolutionary -character of this mutability becomes more obvious. -The being is formed, it grows; then in most cases, -after having passed through the stages of youth and -adult age, it grows old, declines and dies, and is<span class="pagenum" id="Page_189">[Pg 189]</span> -disorganized after having gone through what we may -call an ideal trajectory. This march in a fixed -direction with its points of departure, its degrees, and -its termination, is a repetition of the path that the -ancestors of the living being have already followed.</p> - -<p>Here, then, is a characteristic fact of vitality, or -rather there are two facts. The one consists in this -morphological and organic evolution, the negation of -immutability, the negation of the indefinite maintenance -of a permanent state or form which is -regarded, on the contrary, as the condition of inert, -fixed stable bodies, eternally at rest. The other -consists in the repetition, realized by this evolution, -of the similar evolution of its ancestors; this is a -fact of heredity. Finally, evolution is always in a -cycle—that is to say, that it comes to an end which -brings the course of things to their point of departure.</p> - -<p>This kind of internal activity of the living being -is so striking, that not only does it serve us to -differentiate the living being from the inert body, -but it gives rise to the illusion of a kind of internal -demon, vital force, manifested by the more or less -apparent acts of the life of relation, of the motricity, -of the displacement, or by the less obvious acts of -vegetative life.</p> - -<p><i>Vital Phenomena regarded as a Reaction of the -Ambient World. Their Twofold Conditioning.</i>—In -reality, as the doctrine of energetics teaches us, the -phenomena of vitality are not the effect of a purely -internal activity. They are a reaction of the environment. -“The idea of life,” says Auguste Comte, -“constantly assumes the necessary correlation of two -indispensable elements:—an appropriate organism -and a suitable environment. It is from the reciprocal<span class="pagenum" id="Page_190">[Pg 190]</span> -action of these two elements that all vital phenomena -inevitably result.” The environment furnishes the -living being with three things:—its matter, its -energy, and the exciting forces of its vitality. All -vital manifestation results from the conflict of two -factors: the extrinsic factor which provokes its -appearance; the intrinsic factor, the very organization -of the living body, which determines its form. -Bichat and Cuvier saw in the phenomena of life the -exclusive intervention of a principle of action entirely -internal, checked rather than aided by the universal -forces of nature. The exact opposite is true. The -protozoan finds the stimuli of its vitality in the -aquatic medium which is its habitat. The really -living particles of the metazoan—that is to say, its -cells, its anatomical elements—meet these stimuli in -the lymph, in the interstitial liquids which bathe -them and which form their real external environment.</p> - -<p>Auguste Comte thoroughly understood this truth, -and has clearly expressed it in the passage we have -just quoted. Claude Bernard has fully developed it -and given it its classical form.</p> - -<p>In order to manifest the phenomena of vitality, -the elementary being, the protoplasmic being, requires -from the external world certain favourable -conditions; these it finds there, and they may be -called the stimuli, or extrinsic conditions of vitality. -This being possesses no initiative or spontaneity in -itself, it has only a faculty of entering into action -when an external stimulus provokes it. This subjection -of the living matter is called <i>irritability</i>. -The term expresses that life is not solely an internal -attribute, but an internal principle of action.</p> - -<p><span class="pagenum" id="Page_191">[Pg 191]</span></p> - - -<h4>§ 1. <span class="smcap">Extrinsic Conditions.</span></h4> - -<p><i>Extrinsic Conditions.</i>—By showing that every vital -manifestation results from the conflict of two factors: -the extrinsic or physico-chemical conditions which -determine its appearance, and the intrinsic or organic -conditions which regulate its form, Claude Bernard -dealt a mortal blow at the old vitalist theories. For -he has not only asserted the close dependence of the -two kinds of factors, but he has shown them in action -in most physiological phenomena. The study of the -extrinsic or physico-chemical conditions necessary to -vital manifestations teaches us our first truth—namely, -that they are not infinitely varied as might -be supposed. They present, on the contrary, a -remarkable uniformity in their essential qualities. -The fundamental conditions are the same for the -animal or vegetable cells of every species. They are -four in number:—<i>moisture</i>, the air, or rather <i>oxygen</i>, -<i>heat</i>, and a certain <i>chemical constitution</i> of the medium, -and the last condition, the enunciation of which -seems vague, becomes more precise if we look at it -a little closer. The chemical constitution of media -favourable to life, the media of culture, obeys three -general laws. It is the knowledge of these laws -which formerly enabled Pasteur, Raulin, Cohn, and -Balbiani to provide the media appropriate to the -existence of certain relatively simple organisms, and -thus to create an infinitely valuable method for -the study of nutrition, etc.,—namely, the <i>method of -artificial cultures</i>, numerous developments of which -have been shown us by microbiology and physiology.</p> - -<p><i>The Optimum Law.</i>—It has been said, and it is -more than a play on words, that the conditions of<span class="pagenum" id="Page_192">[Pg 192]</span> -the vital medium were the conditions of the <i>juste -milieu</i>. Water is wanted, there must not be too -much or too little. Oxygen is necessary, and also in -certain proportions. Heat is required, and for that, -too, there is an optimum degree. Certain chemical -compounds are needed and, in this respect too, there -must also be <i>optima</i> proportions.</p> - -<p>Water is a constituent element of the organisms. -They contain fixed proportions for the same tissue, -proportions varying from one tissue to another -(between 2∕3 and 9∕10). The cell of a living tissue requires -around it an aqueous atmosphere, formed by -the different juices of the organism, the interstitial -liquids, the blood, and the lymph. We are deceived -by appearances when we distinguish between aerial, -aquatic, and land-dwelling animals, and when we -speak of the air, the water, and the land as their -natural environment. If we go to the bottom of -things, and fix our attention on the real living -unities, on the cells of which the organism is composed, -we shall find around them the juices, rich in water, -which are their real environment. If these juices are -diluted or concentrated the least in the world, life -stops. The cell, the whole animal, falls into a state -of latent life, or dies. “All living beings are aquatic,” -said Claude Bernard. “Beings that live in the air are -in reality wandering aquariums,” said another physiologist. -“No moisture, no life,” wrote Preyer. The -environment must contain water, but it must contain -it in certain proportions. In the higher animals -there is a mechanism which works automatically to -keep at a constant level the quantity of water in the -blood. Researches on the lavage of the blood (A. -Dastre and Loye) have clearly shown this.</p> - -<p><span class="pagenum" id="Page_193">[Pg 193]</span></p> - -<p>Oxygen is also necessary to life. It is the <i>pabulum -vitæ</i>. But the discovery of the beings called by -Pasteur <i>anaerobia</i> appears to contradict this statement. -Pfeffer, the illustrious botanist, was certain, -in 1897, that the dogma of the necessity of oxygen -no longer held good. This is no longer tenable. -In 1898 Beijerinck carried out most careful researches -on anaerobia said to have been cultivated -in a vacuum, such as the <i>bacteria of tetanus</i> and the -<i>septic vibrion</i>; or on those to which oxygen seems to -be a poison, such as the <i>butyric</i> and the <i>butylic -ferments</i>, the anaerobia of putrefaction, the reducing -spirilla of the sulphates. All use free oxygen. They -consume very little it is true; they are micro-aerobia. -The other organisms, on the contrary, need more. -They are macro-aerobia or simply <i>aerobia</i>. Besides, -if the so-called anaerobia take little or no free -oxygen, it matters little. They take the oxygen -in combination. It may be said with L. Errera -that they have an affinity for oxygen, for they -extract it from its combinations, and that “they -are so well adapted to this mode of existence that -life in the open air being too easy no longer suits -them.” There are for the different animal species -different optima of oxygen.</p> - -<p>Living beings require a certain amount of heat. -Life, which could not have existed on the globe when -it was incandescent, will not be able to exist when it -is frozen. For each organism and each function -there is a maximum and a minimum of temperature -compatible with activity. There is also an optimum. -For instance, the optimum is 29° C for the germination -of corn.</p> - -<p>The condition of the optimum exists in the same<span class="pagenum" id="Page_194">[Pg 194]</span> -way for the chemical composition of the vital medium—and -for the other ambient physical conditions, such -as atmospheric pressure.</p> - -<p>It is therefore a law of <i>universal</i> scope, a regulating -law, as it were, of life. Life is a function of extrinsic -variables, water, air, heat, the chemical composition of -the medium, and pressure. “Every vital phenomenon -begins to be produced, starting from a certain stage -of the variable (minimum), becomes more and more -vigorous as it increases up to a determinate value -(optimum), weakens if the variable continues to increase, -and disappears when it has reached a certain -limiting value (maximum).” This law, proved by -Sachs, the German botanist, in 1860, apropos of the -action of temperature on the germination of plants, -by Paul Bert in 1875, apropos of the action of oxygen -and of atmospheric pressure on animals, and already -formulated at that time by Claude Bernard, was -illustrated by Leo Errera in 1895. It is a law of -moderation. It expresses La Fontaine’s “<i>rien de -trop</i>” Terence’s “<i>ne quid nimis</i>,” the μηδὲν ἄγαν of -Theognis, and the biblical phrase “<i>omnia in mensura -et numero et pondere</i>.” L. Errera sees the profound -cause of this optimum law in the properties of the -living protoplasm, which are mean properties. It -is semi-liquid. It is composed of albuminoid substances, -which can stand no extremes either from the -physical or from the chemical points of view.</p> - - -<h4>§ 2. <span class="smcap">Intrinsic Conditions. The Law of the -Constitution of Organs and Apparatus.</span></h4> - - -<p><i>Law of the Constitution of Organs and Apparatus.</i>—If -we consider more highly organized beings, the<span class="pagenum" id="Page_195">[Pg 195]</span> -influence of the intrinsic conditions appears quite -as clearly. As we have seen, this is so that the -requisite fundamental materials may be spent by -each element in suitable proportions,—water, chemical -compounds, air, and heat,—that organs may be added -to organs, and that apparatus may be set to work in -complex structures. Why a digestive apparatus? -To prepare and introduce into the internal medium -liquid materials which are necessary to life. Why a -respiratory apparatus? To impart the vital gas -necessary to the cells, and to expel the gaseous -excrement, the carbonic acid which they reject. -Why a circulatory apparatus? To transport and -renew this medium throughout. The apparatus, the -functional wheels, the vessels, the digestive and -respiratory mechanisms do not exist for themselves, -like the random sketches of an artistic nature. They -exist for the innumerable anatomical elements which -people the economy. They are arranged to assist -and more rigorously to regulate cellular life with -respect to the extrinsic conditions which it demands. -They are, in the living body, as in civilized society, -the manufactories and the workshops which provide -for the different members of society dress, warmth, -and food. In a word, the <i>law of the construction of -organisms</i> or of the <i>bringing to perfection of an -organism</i> is the same as the law of cellular life. It -is otherwise suggestive as the law of <i>division of -physiological labour</i> formerly enunciated by Henry -Milne-Edwards; and in every case it has a more -concrete significance. Finally, it brings the organic -functional activity into relation with the conditions of -the ambient medium.</p> - -<p><i>How Experiment acts on the Phenomena of Life.</i>—<span class="pagenum" id="Page_196">[Pg 196]</span> -The two orders of conditions, the one provided by the -being itself, the other by external agents, are equally -indispensable—and therefore of equal importance or -dignity. But they are not equally accessible to the -experimentalist. It is not easy to exercise on the -organization direct and measurable actions. On the -contrary, the physical conditions are in the hands -and at the discretion of the experimenter. By them -he may reach the vital manifestations as they appear, -stimulate or check them, defer or precipitate them. -Thus, for instance, the physiologist suspends or re-establishes -at his will full vital activity in a multitude -of reviviscent or hibernating beings, such as grains, -the infusoria capable of <i>encystment</i>, the vibrio, the -tardigrade, the cold-blooded animals, and perennial -plants.</p> - -<p>The ambient world therefore furnishes to the animal -and to the vegetable, whole or fragmentary, those -materials of its organization which are at the same -time the stimuli of its vitality. That is to say, the -vital mechanism would be a dormant and inert -mechanism if nothing in the surrounding medium -could provoke it to action or give it a check. It -would be a kind of steam engine without coal and fire.</p> - -<p>Living matter, in other words, does not possess real -spontaneity. As I have shown elsewhere, the law of -inertia which it is supposed it obeys with inert bodies -is not special to them. It is applied to the living -bodies whose apparent spontaneity is only an illusion -contradicted by physiology as a whole. All the vital -manifestations are responses to a stimulus of acts -provoked, and not of spontaneous acts.</p> - -<p><i>Generalization of the Law of Inertia in Living -Bodies. Irritability.</i>—In fact, vulgar prejudice opposes<span class="pagenum" id="Page_197">[Pg 197]</span> -this view. The opinion of the average man distrusts -it. It applies the law of inertia only to inert matter. -This is because the vital response does not always -immediately succeed the external stimulus, and is not -always proportional to it. But it is sufficient to have -seen the flywheel of a steam engine to understand -that the restitution of a mechanical force cannot be -instantaneous. It is sufficient to have had a finger -on the trigger of a firearm to know that there is no -necessary proportion between the intensity of the -stimulus and the magnitude of the force produced. -Things happen in the living just as in the inert -machine.</p> - -<p>The faculty of entering into action when provoked -by an external stimulus has received, as we have said, -the name of <i>irritability</i>. The word is not used of -inert matter. However, the condition of the latter is -the same. But there is no need to affirm its irritability, -because no one denies it. We know perfectly -well that brute matter is inert, that all the manifestations -of activity of which it is the theatre are provoked. -Inertia is for it the equivalent of irritability in living -matter. But while it is not necessary to introduce -this idea into the physical sciences, where it has -reigned since the days of Galileo, it was, on the -contrary, necessary to affirm it in biology, precisely -because it was in biology that the opposing doctrine -of vital spontaneity ruled supreme.</p> - -<p>Such was the view held by Claude Bernard. He -never varied on this point. <i>Irritability</i>, said he, is the -property possessed “by every anatomical element -(that is to say, the protoplasm which enters into its -constitution) of being stimulated into activity and of -reacting in a certain manner under the influence of<span class="pagenum" id="Page_198">[Pg 198]</span> -the external stimuli.” He could not claim that this -was a distinguishing characteristic between living -bodies and brute bodies, and that all the less because -he always tried to efface on this point the distinctions -which were current in his time, and which were -established by Bichat and Cuvier. And so also Le -Dantec does not seem to have thoroughly grasped -the ideas of the celebrated physiologist on this point -when he asserts, as if he were thereby contradicting -the opinion of Claude Bernard and his school, that -irritability is not something peculiar to living bodies.<a id="FNanchor_17" href="#Footnote_17" class="fnanchor">[17]</a></p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_199">[Pg 199]</span></p> -<h3 class="nobreak" id="CHAPTER_V_3">CHAPTER V.<br /> - -<small>THE SPECIFIC FORM. ITS ACQUISITION. -ITS REPARATION.</small></h3></div> - - -<p class="prel">§ 1. Specific form not special to living beings—Connected with -the whole of the material conditions of the body and the -medium—Is it a property of chemical substance?—§ 2. -Acquisition and re-establishment of the specific form—Normal -regeneration—Accidental regeneration in the protozoa -and the plastids—In the metazoa.</p> - - -<h4>§ 1. <span class="smcap">The Specific Form.</span></h4> - -<p><i>The Specific Form is not Peculiar to Living Beings.</i>—The -position of a <i>specific form</i>—the acquisition of -this typical form progressively realized—the re-establishment -when some accident has altered it—these -are the features which we consider distinctive of living -beings, from the protophytes and the lowest protozoa -to the highest animals. Nothing gives a better idea -of the unity and the individuality of the living being -than the existence of this typical form. We do not -mean, however, that this characteristic belongs to the -living being alone, and is by itself capable of defining -it. We repeat that this is not a case with any -characteristic. In particular the <i>typical form</i> belongs -to crystal as well as to living beings.</p> - -<p><i>The Specific Form depends on the sum of Material -Conditions of the Body and the Medium.</i>—The consideration -of mineral bodies shows us form dependent<span class="pagenum" id="Page_200">[Pg 200]</span> -on the physico-chemical conditions of the body and -the medium. The form depends mainly on physical -conditions in the cases of a drop of water falling from -a tap, of the liquid meniscus in a narrow tube, of a -small navel-shaped mass of mercury on a marble -slab, of a drop of oil “emulsioned” in a solution, and -of the metal which is hardened by hammering or -annealed. In the case of crystals the form depends -more on chemical conditions. It is crystallization -which has introduced into physics the idea that has -now become a kind of postulate—namely, that the -specific form is connected with the chemical composition. -However, it is sufficient to instance the dimorphism -of a simple body, such as sulphur, sometimes -prismatic, sometimes octahedric, to realize that substance -is only one of the factors of form, and that the -physical conditions of the body and of the medium -are other factors quite as influential.</p> - -<p><i>Is the Specific Form a Property of the Chemical -Substance?</i>—How much truer this restriction would -be if we consider, instead of a given chemical compound, -an astonishingly complex mixture, such as -protoplasm or living matter, or the more complex -organism still—the cell, the plastid.</p> - -<p>Are there not great differences between the substance -of the cellular protoplasm, or cytoplasmic -substance, and that of the nucleus? Should we not -distinguish in the former the hyaloplasmic substance; -the microsomic in the microsomes; the linin between -its granulations; the centrosomic in the centrosome; -the archoplasmic in the attraction sphere; not to -mention the different leucins, the vacuolar juice, and -the various inclusions? And in the nucleus must we -not consider the nuclear juice, the substance of the<span class="pagenum" id="Page_201">[Pg 201]</span> -chromosomes, and that of the nucleoles? And is not -each of these probably a very complex mixture?</p> - -<p>However, it is to this mixture that we attribute the -possession of a form, in virtue of and by extension of -the principles of crystallization, which definitely teach -us that these mixtures cannot have form; that form -is the attribute of pure bodies, and is only obtained -by the separation of the blended parts—<i>i.e.</i>, by a -return to homogeneity. There are therefore very -good reasons for hesitating before we transfer the -absolute principle of the dependence between -chemical form and composition, as some philosophical -biologists have done, from the physical -sciences—where it is already subject to serious -restrictions—to the biological sciences.</p> - -<p>Le Dantec, however, has made this principle the -basis of his biological system. He therefore finds in -the crystal the model of the living being. He thus -gives a physical basis to life.</p> - -<p>Is it a question in this system of explaining this -incomprehensible, this unfathomable mystery, which -shows the egg cell attracting to itself materials from -without and progressively building up that amazing -structure which is the body of the animal, the body of -a man, of any given man, of Primus, for example? -It is said that the substance of Primus is specific. -His living substance is his own, special to him; and -that, too, from the beginning of the egg to the end of -its metamorphosis. It only remains to apply to this -substance the postulate, borrowed from crystallography, -of the absolute dependence of the nature of -substance on the form it assumes. The form of the -body of the animal, of the man, of Primus, is the -crystalline form of their living substance. It is the<span class="pagenum" id="Page_202">[Pg 202]</span> -only form of equilibrium that this substance can -assume under the given conditions, just as the cube is -the crystallized form of sea salt, the only state of -equilibrium of chloride of sodium in slowly evaporated -sea water. Thus the problem of the living form is -reduced to the problem of the living substance, which -seems easier; and at the same time the biological -mystery is reduced to a physical mystery. It is clear -that this way of looking at things simplifies prodigiously—and, -we must add, simplifies far too much—the -obscure problem of the relation of form to -substance, simultaneously in the two orders of science. -This may be summed up in a single sentence: -There is an established relation between the specific -form and the chemical composition: the chemical -composition <i>directs</i> and implies the specific form.</p> - -<p>We need not now examine the basis of this opinion. -If it is nothing but a verbal simplification, a unification -of the language applied to the two orders of -phenomena, it implies an assimilation of the mechanisms -which realize them. To the organogenic forces -which direct the building up of the living organisms -it brings into correspondence the crystallogenic forces -which group, adjust, equilibrate, and harmonize the -materials of the crystal.</p> - -<p>When it is a question of the application of a -principle such as this, in order to test its legitimacy -we must always return to the experimental foundations. -Let us imagine, for example, a simple body, -such as sulphur, heated and brought to a state of -fusion—that is to say, homogeneous, isotropic, in an -undisturbed medium the only change in which will -be a very gradual cooling down. These are the -typical crystallogenic conditions. The body would<span class="pagenum" id="Page_203">[Pg 203]</span> -take a given crystalline form. It is from experiments -such as this that we derive the idea of <i>a specific form -connected with a chemical constitution</i>.</p> - -<p>But in drawing this conclusion our logic is at fault. -The real interpretation suitable to this case, as in all -others, is that the specific form is suitable to the -substance, and also to the physical, chemical, and -mechanical conditions in which it is placed. And -the proof is that this same substance, sulphur, which -takes the prismatic form immediately after fusion, -will not retain that form, but will pass on to the -quite different octahedral form.</p> - -<p>It is so with the specific form of the living being—that -is to say, with the assemblage of its constituent -materials co-ordinated in a given system—in a word, -with its organization. This is suitable to its substance, -and to all the material, physical, chemical, -and mechanical conditions in which it is placed. This -form is the condition of material equilibrium corresponding -to a very complex situation, to a sum of -given conditions. The chemical condition is only -one of these. And further, it is hardly proper to -speak of a “chemical substance” when we refer to an -astonishingly complex mixture which is in addition -variable from one point to the other of the living -body. When we thus reduce phenomena to their -original signification, false analogies disappear. To -say with Le Dantec that the form of the greyhound -is the condition of equilibrium of the “greyhound -chemical substance” is saying much; and too much, -if it means that the body of the greyhound has a -substance which behaves in the same way as homogeneous, -isotropic masses like melted sulphur and -dissolved salt. It were better to say much less, if it<span class="pagenum" id="Page_204">[Pg 204]</span> -means, as it will in the minds of the physiologists, -that the body of the greyhound is the condition of -equilibrium of a heterogeneous, anisotropic, material -system, subjected to an infinite number of physical -and chemical conditions.</p> - -<p>The idea of connecting form, and by that we mean -organization, with chemical composition did not arise -in the minds of chemists or physiologists. Both have -expressed themselves very clearly on this point.</p> - -<p>“We must distinguish,” said Berthelot, “between -the formation of the chemical substances, the assemblage -of which constitutes organized beings, and the -formation of the organs themselves. This last problem -does not come into the domain of chemistry. No -chemist will ever claim to have formed in his laboratory -a leaf, a fruit, a muscle, or an organ.... But chemistry -has a right to claim that it forms direct principles—that -is to say, the chemical materials which constitute -the organs.” And Claude Bernard in the same way -writes:—“In a word, the chemist in his laboratory, -and the living organism in its apparatus, work in the -same way, but each with its own tools. The chemist -can make the products of the living being, but he -will never make the tools, because they are the result -of organic morphology.”</p> - - -<h4>§ 2. <span class="smcap">The Acquisition and Re-establishment -of the Specific Form.</span></h4> - - -<p><i>Acquisition of the Typical Form.</i>—The acquisition -of the typical form in the living being is the result of -ontogenic work which cannot be examined here. In -the elementary being, the plastid, this work is blended<span class="pagenum" id="Page_205">[Pg 205]</span> -with the work of nutrition. It is <i>directed nutrition</i>. -It consists of a simple increase from the moment the -element is born by the division of an anterior element, -and of a necessarily restricted differentiation. It is a -rudimentary embryogeny. In the complex being, -metazoan or metaphyte, the organism is constituted, -starting from the egg, by the growth, by the bipartition -of the elements, and their differentiation, accomplished -in a certain direction and in conformity with -a given plan. This, again, is directed nutrition, but -here the embryogeny is complex. The directing plan -of operations is no doubt the consequence of the -material conditions realized each moment in the -organism.</p> - -<p><i>Normal Regeneration.</i>—Not only do living beings -themselves construct their typical architecture, but -they re-establish it and continually reconstitute it, -according as accidents, or even ordinary circumstances, -tend to destroy it; in a word, they become rejuvenescent. -This regeneration consists in the reformation -of the parts that are altered or carried away in the -normal play of life, or by the accidents which disturb -its course.</p> - -<p>Thus there is a <i>normal physiological regeneration</i>, -which is, so to speak, the prolongation of the ontogenesis—<i>i.e.</i>, -of the work of formation of the individual. -We have examples in the reconstitution of the skin -of mammals—in the throwing off of the epidermic -products constantly used up in their superficial and -distal parts and regenerated in their deeply-seated -parts; in the loss and the renewal of teeth at the -first dentition and in certain fish in the fact of -successive dentitions; in the periodical renewal of -the integument in the larvæ of insects, and in the<span class="pagenum" id="Page_206">[Pg 206]</span> -crustaceæ; and finally in the destruction and the -neo-formation of the globules of the blood of vertebrates, -of the glandular cells, and of the epithelial -cells of the intestine.</p> - -<p><i>Accidental Regeneration in Protozoa and Plastids.</i>—There -is also an <i>accidental regeneration</i> which more or -less perfectly renews the parts that are lost. This -regeneration has its degrees, from the simple cicatrization -of a wound to the complete reproduction of the -part cut off. It is very unequally developed in -zoological groups even when they are connected. -In the elementary monocellular beings—<i>i.e.</i>, in the -anatomical elements and in the protozoa,—the experiments -in merotomy, <i>i.e.</i>, in <i>partial section</i>, enable us -to appreciate the extent of this faculty of regeneration. -These experiments, inaugurated by the researches -of Augustus Waller in 1851, were repeated -by Gruber in 1885, continued by Nussbaum in 1886, -Balbiani in 1889, Verworn in 1891, and have been -reproduced by a large number of observers. They -have shown that the two fragments cicatrize, and are -repaired, building up an organism externally similar -to the primitive organism, but smaller. The two new -organic units do not, however, behave in the same -way. That which retains the nucleus possesses the -faculty of regeneration, and of living as the primitive -being lived. The protoplasmic fragment, which does -not contain the nucleus, cannot rebuild this absent -organ; and though it has functional activity in most -respects, just as the nucleated fragment, yet it is -distinguished from it in others of great importance. -The anucleated fragment of an infusorian behaves as -the nucleated, and as the whole animal so far as the -movements of the body, the cilia, prehension of food,<span class="pagenum" id="Page_207">[Pg 207]</span> -evacuation of fæces, and the rhythmical contraction -of the pulsatile vesicules are concerned. But -Balbiani’s researches in 1892 have shown us that -secretion, complete regeneration, and the faculty of -reproduction by fission can take place only in the -nucleated fragment—<i>i.e.</i>, in the nucleus.</p> - -<p><i>Accidental Reproduction in the Metazoa.</i>—Among -multicellular beings the faculty of reproduction is met -with in the highest degree in plants, where we find it -in the process of propagation by slips. In animals it -is the most marked in Cœlenterata. Trembley’s -experiments are a striking instance. We know that -when the hydra is cut into tiny pieces it reproduces -exactly as many complete beings. Among the -worms, Planaria afford a similar example. Every -fragment, provided its volume is not less than a tenth -of that of the whole, can reproduce a complete, entire -being. The snail can produce a large part of its head, -including the tentacles and the mouth. Among the -Tritons and the Salamanders the faculty of regeneration -reproduces the limbs, the tail, and the eye. In -the Frog family, on the contrary, the work of regeneration -does not go beyond cicatrization, and it is -the same with Birds and Insects.</p> - -<p>It is really startling to see in a vertebrate like the -Triton the stump of an arm with its fragment of -humerus reproducing the forearm and the hand in all -their complexity, with their skeleton, blood vessels, -nerves, and teguments. We say that the limb has -<i>budded</i>, as if there were a germ of it which develops -like the seed of a plant, or as if each transverse portion -of the limb, each slice, so to speak, could re-form the -slice that follows.</p> - -<p>The mechanism of generation and that of regenera<span class="pagenum" id="Page_208">[Pg 208]</span>tion -alike raise problems of the highest importance. -Does the part become regenerated just as it was -formed at first? Does the regeneration repeat the -ontogeny? Is it true that a lost organ is never regenerated -(the kidney for instance)? Does the -symmetrical organ enjoy a compensating and hypertrophic -development, as Ribbert has asserted? And -further, if the organ be removed and transplanted to -another position, can it be grafted there, as Y. Delage -maintains? These are very important questions; but -if we dwell upon them, we shall be diverted from our -immediate object. Our task is to look at these facts -from the point of view of their significant and characteristic -meaning in vitality. Flourens invoked on -their behalf the intervention of vital forces, <i>plastic</i> -and <i>morphoplastic</i>. But, as we shall see later, these -phenomena of cicatrization, of reparation, of regeneration, -these more or less complete efforts for -the re-establishment of the specific form, although -they are found in all living beings in different degrees, -are not exclusively confined to them. We find them -again in some representatives of the mineral world—in -crystals, for instance.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_209">[Pg 209]</span></p> - -<h3 class="nobreak" id="CHAPTER_VI_3">CHAPTER VI.<br /> - -<small>NUTRITION.</small></h3></div> - - -<p class="prel">FUNCTIONAL ASSIMILATION. FUNCTIONAL DESTRUCTION. -ORGANIC DESTRUCTION. ASSIMILATING -SYNTHESIS.</p> - - -<p class="prel">The extreme importance of nutrition—§ 1. Effect of vital -activity—Destruction or growth—Distinction between the -living substance and the reserve-stuff mingled with it—Organic -destruction—Destruction of reserve-stuff—Destruction -of living matter—Growth of living matter—§ -2. The two categories of vital phenomena—Foundations -of the idea of functional destruction—The two kinds of -phenomena of vitality—Criticism of Claude Bernard—Current -views—Criticism of Le Dantec’s new theory of -life.—§ 3. Correlation of the two kinds of vital facts—Law -of connection—Contradictions in the new theory.—§ 4. The -characteristics of nutrition—Its definition—Its permanence—Erroneous -idea of the vital vortex—Formative assimilation -of reserve-stuff—Formative assimilation of protoplasm—Death, -real and apparent.</p> - - -<p><i>The Immense Importance of Nutrition.</i>—We now -come to the important feature of vitality. All other -characteristics of living matter, its unstable equilibrium, -its chemical and anatomical organization, the acquisition -and the maintenance of a typical form, are only -secondary properties, so to speak, subordinate with -reference to <i>nutrition</i>. Generation itself is only a -mode. <i>Nutrition</i> is the essential attribute of life. It -is life itself.</p> - -<p><span class="pagenum" id="Page_210">[Pg 210]</span></p> - -<p>Before we define it a few preliminary explanations -are necessary.</p> - -<p>The most striking thing in living matter is its -<i>growth</i>. An animal, a vegetable, is something which -is first more or less minute, and which grows. Its -characteristic is to expand—from the spore, the seed, -the slip, the egg—it grows.</p> - -<p>Whether we are dealing with a cellular element, a -plastid, or a complex being, their condition is the -same in this respect. No doubt when the animal or -plant has reached a certain stage of development its -growth is stopped, and for a more or less lengthy -period it remains in the adult stage, in what seems to be -equilibrium. But even then there is no check in the -manufacture of living matter; there is only a compensation -between its production and its destruction.</p> - -<p>It is important to reduce to order the ideas on this -important subject, which at present are confused, -inconsistent, and contradictory. In biology grievous -confusion reigns.</p> - - -<h4>§ 1. <span class="smcap">Effect of the Vital Activity. -Destruction or Growth?</span></h4> - -<p><i>Distinction between the Living Substance and the -Reserve-stuff mingled with it.</i>—The physiology of -nutrition has given rise to a vast body of research -during the last half-century. Physiological schools, -masters and pupils, such as the school at Munich -under Voit and Pettenkofer, Pflüger’s at Bonn, -Rubner’s, and those of Zuntz and von Noorden at -Berlin, and a large number of zootechnical and agricultural -laboratories through the whole world have for<span class="pagenum" id="Page_211">[Pg 211]</span> -years past been engaged in analyzing ingesta and -egesta, in drawing up schedules of nutrition, in order -to determine the course of decomposition and reconstitution -of the living material.</p> - -<p>If I were asked what, in my opinion, is the most -general result of all this labour, I would reply that it -has affirmed and corroborated the important distinction -which must be drawn between <i>living substance, -properly so called</i>, and <i>reserve-stuff</i>. The latter, the -<i>reserve-stuff</i> of albuminoids, carbohydrates, and fats, -are so intimately intermingled with the living substance -that they are in most cases very difficult to -distinguish from it.</p> - -<p><i>Organic Destruction.</i>—A second point, which is -placed equally beyond doubt, is that the vital functional -activity is accompanied by a destruction of the -immediate principles of the organism, in the direction -of their simplification. This functional destruction -cannot be doubted in the case of differentiated organs -in which the functional activity is evident, intermittent, -and in some measure distinct from the other -vital phenomena which take place in them. For -example, in the case of contracting muscles the -respiratory carbonic acid and urinary carbon are the -irrefutable proofs of this destruction: weak in repose, -abundant during activity, and in proportion to it. -There can be no doubt on this point. The truth -laid down by Claude Bernard under the name of -the <i>law of functional destruction</i> has been doubly -consecrated by experiment and theory. According -to the energetic theory, in fact, mechanical and -thermal energies manifested in the vital functional -activity can only have their source in the chemical -energy set free by the destruction of the immediate<span class="pagenum" id="Page_212">[Pg 212]</span> -principles of the organism, reduced to a lower degree -of complexity.</p> - -<p><i>Destruction of Reserve-stuff.</i>—But now the disagreement -begins. What are these decomposed, destroyed -principles? Do they belong to the cellular reserve-stuff -or to the living matter properly so called? -There is no doubt that most of them belong to the -reserve-stuff. For example, this is especially true of -glycogen, which is consumed in muscular contraction -just as coal is consumed in the furnace of the locomotive; -and glycogen is a reserve-stuff of muscle. -These reserve-stuffs destroyed in the functional -activity can be built up again only during repose.</p> - -<p>But it is not yet certain whether the living -matter itself, the active protoplasm, the muscular -protoplasm, takes part in this destruction, whether it -provides it with elements. Experiments have proved -contradictory. Experimenters have isolated the nitrogenous -wastes (urea) after muscular labour, and they -have compared them with the wastes of the period of -repose. These nitrogenous wastes bear witness to the -destruction of albuminoid substances, and the latter -are the constituent principles of living matter. If—under -conditions of sufficient alimentation—the muscular -functional activity involves more nitrogenous -waste, <i>i.e.</i>, a greater destruction of albuminoids, it -might be supposed that the living material properly -so called has been used up and destroyed for its -own purposes. (And here again there might be a -reserve-stuff of albuminoids, distinct from the living -protoplasm itself, and more or less incorporated -with it.)</p> - -<p>But experiment so far has not given decisive results. -The latest experimental researches, such as those of<span class="pagenum" id="Page_213">[Pg 213]</span> -Igo Kaup, of Vienna, which date from 1902, tell us as -uncertain a tale as their predecessors. The increase -in the destruction of albumen has not been constant; -the conditions of the observations do not justify our -making an assertion either <i>pro</i> or <i>con</i>.</p> - -<p><i>Destruction of Living Matter.</i>—As no certain -answer is supplied by experiment, theory intervenes -and gives two conflicting answers. The majority of -physiologists are inclined to believe in <i>the destruction -of the living substance as the result of its own functional -activity</i>. The functional activity would therefore -destroy not only the reserve-stuff, but also the -protoplasmic material. This is the current view. -Only this opinion is strongly challenged by the -positive teaching of science. It is certain that this -material, in the muscle, is but little attacked, if it -is attacked at all. We have seen above that the -physiologists, with Pflüger and Chauveau, are agreed -on this point. The vital functional activity in particular -is destructive to the reserve-stuffs. It does -not destroy them much; it destroys the organic -material still less. Both would be repaired in functional -repose.</p> - -<p><i>Growth of Living Matter.</i>—The second assertion is -diametrically opposed to this. Not only, says Le -Dantec, is the muscle not destroyed in the functional -activity, but it grows. Contrary to universal opinion, -the protoplasmic material increases by activity, and it -is destroyed in repose. There would thus be a -general law—<i>the law of functional assimilation</i>. “A -cell of brewers’ yeast when introduced into a sugared -must makes this must ferment, and at the same time, -so far from destroying it, it increases it. Now, the -fermentation of the must is exactly the same as the<span class="pagenum" id="Page_214">[Pg 214]</span> -functional activity of the yeast.” It is, says the same -author, a mistake to believe that the phenomena of -functional activity, of <i>vital activity</i>, only takes place -at the price of organic destruction. Here, then, are -these two competing views. They are not so very far -apart as a matter of fact, since the question at issue is -one of deciding between a slight destruction and a -slight growth, but theoretically they are strongly -opposed. Moreover, they are arbitrary, and <i>experiment</i> -has not decided between them.</p> - - -<h4>§ 2. THE TWO CATEGORIES OF VITAL PHENOMENA.</h4> - -<p><i>Foundation of the Idea of Functional Destruction. -Claude Bernard.</i>—The doctrine of functional destruction -has been laid down with remarkable power -by Claude Bernard. But the terms in which he has -expressed it in a measure betray the thoughts of the -great physiologist, or, at any rate, overstep the -immediate fact he had in view. “The phenomena -of destruction are very obvious. When movement is -produced, when the muscle contracts, when volition -and sensibility are manifested, when thought is -exercised, when the gland secretes, then the substance -of the muscles, of the nerves, of the brain, of -the glandular tissue, becomes disorganized, destroyed, -and consumed. So that every manifestation of a -phenomenon in the living being is necessarily connected -with an organic destruction.” To Claude -Bernard organic destruction is a truth. To Le Dantec -it is an error. Which is right? Clearly Claude -Bernard. He bases his conviction on the analyses -of the materials excreted in the process of physio<span class="pagenum" id="Page_215">[Pg 215]</span>logical -work. The excreta bear witness to a certain -organic demolition. Generalizing this teaching of -experiment the illustrious biologist divined the -fundamental law of energetics before the idea of -energetics had made much way in France. Every -act which expends energy, which produces heat or -motion, any manifestation whatever that may be -looked upon as an energetic transformation, necessarily -expends energy, and that energy is borrowed -from the substance of the organism. These substances -are simplified, broken up, and destroyed. -Now the functional activity of the muscle produces -heat and movement in warm-blooded as well as in -cold-blooded animals. The functional activity of -the glands produces heat, as has been shown by the -celebrated experiments of C. Ludwig on the salivary -secretion, and as is also shown by the study of thermal -topography in the vertebrates. The functional activity -of the nerves and the brain produces a slight quantity -of electricity and heat, as most observers have agreed. -The functional activity of the electrical and of the -photic apparatus also expends energy. Finally, the -eye which receives the photic impression destroys the -purple matter of the retina, and that purple matter, -as we well know, is recuperated in the dark during -the repose of the organ. Everything that is expressed -objectively, everything that is a phenomenon in the -living being—with the exception of growth and -formation, which are generally slow phenomena, and -of which we can only get an idea by the comparison -of successive states—all these energetic manifestations -suppose a destruction of organic matter, a chemical -simplification, the source of the energy manifested. -And that is why material destruction does not merely<span class="pagenum" id="Page_216">[Pg 216]</span> -coincide with functional activity, but is its measure -and expression.</p> - -<p><i>The Two Kinds of Phenomena of Vitality.</i>—Another -point on which Claude Bernard is right and his -opponent is wrong is not less fundamental. What -are we to understand by functional phenomena? -This is the very point at issue. Now, in the mind of -physiologists, this expression has a perfectly definite -meaning. It is not so with Le Dantec. Physiologists -who have studied animals rather high in organization—in -which the differentiation of phenomena enables -us to grasp the fundamental distinction—have readily -recognized that the phenomena of living beings are -divided into two categories. There are some which -are intermittent, alternative, which take place, or grow -stronger at certain moments, but which cannot be -continuous—they are the <i>functional acts</i>; there are -others in which this characteristic of explosives, -energetic expenditure and intermittence, do not -appear—they are, in general, the <i>nutritive acts</i>. The -muscle which contracts shows functional activity. It -has an activity and a repose. During this apparent -repose we must not say that it is dead; it has a life, -but that life is obscure as far as the salient fact of -functional movement is concerned. The salivary -gland which throws up waves of saliva when the food -is introduced and masticated in the mouth, or when -the chord of the tympanum is at work, is in a state of -functional activity; this is the salient phenomenon. -But before, though nothing, absolutely nothing, was -flowing through the glandular canal, yet the gland -was not reduced to the condition of a dead organ: it -was living a more obscure, a less evident life. The -microscopical researches of Kühne, Lea, and Langley,<span class="pagenum" id="Page_217">[Pg 217]</span> -now universally verified, show us that during this -time of apparent repose the cells were loading up -their granulations and getting ready the materials of -secretion, as just now the muscle at rest was accumulating -glycogen and the reserve-stuff which are to be -expended and destroyed in contraction. Similarly, -with regard to the functional activity of the other -glands, of the brain, etc. Claude Bernard was, therefore, -perfectly right, when he took as his model the -chemists who distinguished between exothermic and -endothermic reactions, and who classed the phenomena -of life into two great divisions: those of -functional activity, and those of functional repose.</p> - -<p>1st. <i>The phenomena of functional activity</i> “are -those which ‘leap to the eyes,’ and by which we -are inclined to characterize life. They are conditioned -by the effects of wear and tear, of chemical -simplication, and of the organic destruction which -liberates energy.” And it must be so, because these -functional manifestations expend energy. These -phenomena, which are the most obvious, are also the -least specific phenomena of vitality. They form -part of the general phenomenality.</p> - -<p>2nd. The <i>phenomena</i> which accompany <i>functional -repose</i> correspond to the building up of the reserve-stuff -destroyed in the preceding period, to the organizing -synthesis. The latter remains “internal, silent, -concealed in its phenomenal expression, noiselessly -gathering together the materials which will be expended. -We do not see these phenomena of -organization directly. The histologist and the -embryogenist alone, following the development of -the element or of the living being, sees the changes -and the phases which reveal this silent effort. Here<span class="pagenum" id="Page_218">[Pg 218]</span> -is a store of substance; there, the formation of -an envelope or a nucleus; there, a division or -multiplication, a renewal.” This type of phenomena -is the only type which has no direct analogues: -it is peculiar, special to the living being: what -is really vital is this evolutive synthesis. Life is -creation.</p> - -<p><i>Criticism of Claude Bernard.</i>—All this is perfectly -true. Thirty years of the most intensive scientific -development have run by since these lines were -written, and have not essentially changed the ideas -therein expressed. His work in its broad lines -remains intact. Does that imply, however, that -everything is perfect in detail and expression, and -that there is no reason for making it more precise or -for giving it fresh form? No doubt this is not so. -Although Claude Bernard contributed to establish -the essential distinction between the real living -protoplasm and the materials of reserve-stuff which -it contains, he has not drawn a sufficiently clear -distinction between what belongs to each of the -categories. He has not specified, in relation to -organic destruction, what bearing it has on the -organic materials of reserve-stuff. Sometimes he uses -the term “organic destruction,” which is correct, and -sometimes “vital destruction,” which is of doubtful -import. Further, he employs an obscure and -paradoxical formula to characterize the obvious but -nevertheless not specific phenomena of organic -destruction, and he says: “life is death.”</p> - -<p><i>Current Views.</i>—Nowadays, if I may express a -personal opinion on this important distinction between -functional activity and functional repose, I -should say that after having distinguished between<span class="pagenum" id="Page_219">[Pg 219]</span> -the two categories of phenomena we must try to -correlate them. We must try to discover, for -instance, what there is in common between the -muscle in repose and the muscle in contraction, and -to perceive in the <i>muscular tonus</i> a kind of bridge -thrown between these two conditions. The functional -activity would be uninterrupted, but it would have its -degrees of activity. The muscular tonus would be -the permanent condition of an activity which is capable -only of being considerably raised or lowered. -Similarly for the glandular functional activity; the -periods of charge must be connected with the periods -of discharge. In a word, following the constant path -of the human mind in scientific knowledge, after -having drawn the distinctions that are necessary to -our understanding of things, we must obliterate them. -After having dug our ditches we must fill them up -again. After having analyzed we must synthesize. -The distinction between the phenomena of <i>functional -activity</i> and the phenomena of <i>functional repose</i> or -<i>purely vegetative</i> and nutritive <i>activity</i>, though only -valid in the case of a provisional and approximate -truth, none the less throws light on the obscure -regions of biology.</p> - -<p>The succession of energy and repose, of sleep and -awakening, is a universal law, or at least a very -general law, connected with the laws of energetics. -The heart, the lungs, the muscles, the glands, the -brain obey in the most obvious manner this obligation -of rhythmical activity. The reason is clear. It is -because the functional activity involves what is -generally a sudden expenditure of energy, and this -has to be replaced by what is generally a slow -process of reparation. Functional activity is an<span class="pagenum" id="Page_220">[Pg 220]</span> -explosive destruction of a chemical reserve which is -built up again more or less slowly.</p> - -<p><i>Criticism of Le Dantec’s “New Theory of Life.”</i>—Let -us now examine the antithesis of Claude -Bernard’s views. There are evidently rudimentary -organisms in which the differentiation of the two -categories of phenomena is but little marked; in -which, apart from the movement, it is impossible to -recognize intermittent, functional activities clearly -distinct from morphogenic activity. It is not in this -domain of the indistinct that we must seek the -touchstone of physiological distinctions. Clearly, we -must not choose these elementary plastids to test -the doctrine of functional assimilation and functional -destruction. But is not this exactly what Le Dantec -did when he began his researches on brewers’ yeast? -When we try to examine things, we must choose the -conditions under which they are differentiated, and -not those in which they are confused. And this is -why, in the significant words of Auguste Comte, “the -more complex living beings are, the better known -they are to us.” The philosopher goes still farther -in this direction, and adds “directly it is a question -of the characteristics of animality we must start from -the man, and see how those characteristics are little -by little degraded, rather than start from the sponge -and endeavour to discover how these characteristics -are developed. The animal life of the man assists -us to understand the life of the sponge, but the -converse is not true.”</p> - -<p>When, moreover, we consider a vegetable organism -such as yeast, which derives its energy, not from -itself, not from the potential chemical energy of its -reserve-stuff, but directly from the medium—that is<span class="pagenum" id="Page_221">[Pg 221]</span> -to say, from the potential chemical energy of the -compounds which form its medium of culture,—we -then find ourselves in the worst possible situation for -the recognition of organic destruction. Further, it is -doubly wrong to assert that in so ill-chosen a type -the functional phenomena do not result from an -organic destruction—for at first there are no very -distinct functional phenomena here—and, in the second -place, there certainly is organic destruction. The -phenomena of the morphogenic vitality detected in -the yeast are the exact concomitants, or the results, -of the destruction of an organic compound, which in -this case is sugar. The yeast destroys an immediate -principle, and this is the point of departure of its vital -manifestations; only, it has not, as a preliminary, -clearly incorporated and assimilated this principle. -When, therefore, the functional phenomena are -effaced and disappear, we none the less find phenomena -of destruction of organic compounds which are -in a measure, a preface to the phenomena of growth. -This is what happens in the case of brewers’ yeast: -and here, again, the two categories of facts exist. -Once more, we find, in the first place, the phenomena -of destruction (destruction of sugar, reduced by -simplification to alcohol and carbonic acid)—phenomena -which this time no longer respond to obvious -functional manifestations; and, in the second place, -the phenomena of chemical and organogenic synthesis, -corresponding to the growth of the yeast and the -multiplication of its protoplasm. The former are no -longer detected, as we have just said, by striking -manifestations. However, it is not true that everything -which is visible and which may be isolated -outside the activity of the yeast is part of those<span class="pagenum" id="Page_222">[Pg 222]</span> -phenomena. The boiling of the juice or the mash, -the heat given off by the copper, all this phenomenal -apparatus is but the consequence of the production of -the carbonic acid and of its liberations—<i>i.e.</i>, the -consequence of the act of destruction of the sugar. -Here is organic destruction with its energetic -manifestations!</p> - -<p>This example of the life of brewers’ yeast, of the -saccharomyces, specially chosen by Le Dantec as -being absolutely clear and giving the best illustration -of his argument, contradicts him at every point. The -general thesis of this vigorous thinker is that we -cannot distinguish between the two parts of the vital -act, organic destruction, and assimilating synthesis; -that these two acts are not successive; that they give -rise to phenomenal manifestations equally evident, -apparent, or striking. Now, in the case of yeast, the -phenomenon of destruction is clearly distinct from -that of the assimilating synthesis which multiplies -the substance of the saccharomyces. In fact, the -action is realized by means of an alcoholic diastase -manufactured by the cell; and Büchner succeeded in -isolating this alcoholic ferment which splits up the -sugar into alcohol and carbonic acid, and also <i>in vitro</i> -and <i>in vivo</i>, makes the vat boil and heats the liquid. -All the yeast is at work at once, says M. Dantec. -No, and this is the proof.</p> - -<p>And, further, Pasteur himself, who had shown the -relation of the decomposition of the sugar to the fact -of the growth of the yeast and of the production -of accessory substances such as succinic acid and -glycerine, always referred to <i>correlation</i> between these -phenomena. The destruction of the sugar is the -<i>correlative</i> of the life of the yeast. This was his<span class="pagenum" id="Page_223">[Pg 223]</span> -favourite formula. It never entered his head that -there could be a confusion instead of a correlation, -and that there might be only one and the same act, -the phases of which would be indistinguishable. -This unfortunate idea, which was fated to be so -rapidly contradicted, is due to Le Dantec. Far -from it being the case, Pasteur had distinguished -the <i>ferment function</i> from the life of the yeast. -According to him, the yeast may exist sometimes as -a ferment and sometimes otherwise.</p> - - -<h4>§ 3. <span class="smcap">Correlation of Two Orders of -Vital Facts.</span></h4> - -<p>It is this correlation between acts <i>distinct in themselves</i> -but <i>usually connected</i> that was announced by -Claude Bernard. And, <i>mirabile dictu</i>—and this is the -natural outcome of the perfect sanity of mind of this -great physiologist—it happens that not only Pasteur’s -researches, but the development of a new science, -Energetics, and Büchner’s discovery lend support to -his views, and that, too, in a field where one would -have thought they had no application. Le Dantec is -wrong when he declares that these ideas only apply to -vertebrates. “It is clear,” he says on several occasions, -“that the author has in view the metazoa and -even the vertebrates.” Well! no. All that is general, -universally applicable, and universally true. So that -there are two orders of distinct phenomena energetically -opposed and certainly connected. We need -only repeat Claude Bernard’s own words quoted by -Le Dantec in order to confute them.</p> - -<p><i>Law of Connection of Two Orders of Vital Facts.</i>—“These -phenomena [of organic destruction and of<span class="pagenum" id="Page_224">[Pg 224]</span> -assimilating synthesis] are simultaneously produced -in every living being, in a connection which cannot -be broken. The disorganization or dissimilation uses -up living matter [by this we must understand the -reserve-stuff, as will be seen later on in the quotation] -in the organs <i>in function</i>: the assimilating synthesis -regenerates the tissues; it gathers together the reserve-stuff -which the vital activity must expend. -These two operations of destruction and renovation, -inverse the one to the other, are absolutely connected -and inseparable, in this sense at any rate, that destruction -is the necessary condition of renovation. -The phenomena of functional destruction are themselves -the precursors and the instigators of material -regeneration, of the formative process which is silently -going on in the intimacy of the tissues. The losses -are repaired as they take place; and equilibrium being -re-established as soon as it tends to be broken, the -body is maintained in its composition.”</p> - -<p>It is perfectly right and wise to say with Claude -Bernard that the two orders of facts are successive, -and that one is normally the inciting condition of the -other. The possibility of the development of the -yeast when fermentation fails, and the weakness of -this development on the other hand under these conditions, -are an excellent proof of this. The one proves -the essential independence of the two orders of facts, -the other the inciting and provoking virtue of the first -relatively to the second. The experimental truth is -thus expressed with a minimum of uncertainty. We -know the facts which led Le Dantec to formulate his -law of functional assimilation—namely, that the -functional activity is useful or indispensable to the -growth of the organ; that the organs which are<span class="pagenum" id="Page_225">[Pg 225]</span> -functionally active grow, and those which do not act -become atrophied. We are only expressing the facts -when we say that the organic destructions that go on in -the living being (whether at the expense of its reserve-stuff -or at the expense of its medium, or whether it be -even slightly at the expense of the plastic substance -itself) are the antecedent, the inciting agent or the -normal condition of the chemical and organogenic -syntheses which create the new protoplasm.</p> - -<p>On the other hand, we are wrong if we hold with -Le Dantec that instead of two chemical operations -there is only one, that which creates the new protoplasm. -The obvious destruction is neglected; it is -deliberately passed over. He does not see that it is -necessary to liberate the energy employed in the -construction, by complication, of this highly complex -substance which is the new protoplasm. He really -seems to have made up his mind not to analyze the -phenomenon. If we decline to admit that to the first -act of functional destruction succeeds a second, -assimilation or organogenic synthesis, we are looking -at elementary beings, in which the succession -cannot be grasped, as we look on brewers’ yeast. -We not only mean that the morphogenic assimilation -results from the functional activity; we mean that it -results from it directly, immediately, that it is the -functional activity itself. Experiment tells us nothing -of all this. It shows us the real facts, the facts of the -destruction of an organic immediate principle, the -sugar, and the fact that an assimilating synthesis is -the correlative of this destruction. Besides, if it is -impossible in examples of this kind to exhibit the -succession, it is perfectly easy in beings of a higher -order. It is, then, clearly seen that the preliminary<span class="pagenum" id="Page_226">[Pg 226]</span> -destruction of a reserve-stuff (and perhaps of a small -quantity of the living substance) precedes and conditions -the formation of a greater quantity of this -living matter—in other words, the growth of the -protoplasm of the organ.</p> - -<p><i>Contradictions in the New Theory.</i>—Moreover, these -mistakes involve those who make them in a series of -inextricable contradictions. Here, for example, is -life; it is found, they say, in three forms:—Life -manifested, or condition 1º; latent life, or condition -3º. So far this is the classical theory; but they add -a condition 2º, which is what might be called <i>pathological -or incomplete life</i>. This is defined by the -following characteristic:—That its functional phenomena -are identical with those in the first form, but -that they are not accompanied by assimilation and by -protoplasmic growth, But since, they say, growth is -the chemical consequence of the functional activity, -since it is so to speak its metabolic aspect, since it is -confused with it, and inseparable from it, by the -argument—then it is contradictory and logically -absurd to speak of condition 2º. It would be acknowledging -in the case of the anucleated merozoite, -for example, a functional activity unaccompanied by -assimilation, yet identical with the functional activity -which is accompanied by assimilation in the nucleated -merozoite. The general movement, that of the cilia, -the taking of food, the evacuation of the fæces, the -contraction of the pulsatile vacuoles, are the same. -And this fact is the best proof that this vital functional -activity (with the organic destruction which is -its energetic source) must be distinguished from the -assimilation which usually follows it, and which in -exceptional cases may not follow it.</p> - -<p><span class="pagenum" id="Page_227">[Pg 227]</span></p> - -<p>We shall carry this discussion no farther. We have -examined at some length Le Dantec’s views, and we -have contrasted them with the doctrine which has -been current in general physiology since the time of -Claude Bernard, and this comparison does not turn -out quite to their advantage. It was inevitable that -the experimental and realistic spirit which inspired -the doctrine of the celebrated physiologist made his -work really too systematic. His formula, “life is -death,” and the form he gave his ideas, are not always -irreproachably correct. They lend themselves at -times to criticism. Sometimes they require commentary. -These are errors of detail which Le Dantec -has summarized somewhat roughly. There is no -necessity to do this in his own case. We pay our -tribute to the clearness of his language, although we -believe the foundations of his system are false and -ill-founded. Their rigour is purely verbal. Their -external qualities, their careful arrangement are well -adapted to the seduction of the systematic mind -prepared by mathematical teaching. This new theory -of life is presented with pedagogic talent of the -highest order. We think we have shown that the -foundations are entirely fallacious, in particular the -following:—Vital condition No. 2º; the confusion between -functional activity and assimilating synthesis; -the so-called absolute connection between morphogeny -and chemical composition; the fundamental -distinction between elementary life and individual life.</p> - - -<h4>§ 4. <span class="smcap">Characteristics of Nutrition.</span></h4> - -<p><i>Definition of Nutrition.</i>—As we have just seen, the -organism is the scene of chemical reactions of two<span class="pagenum" id="Page_228">[Pg 228]</span> -kinds, the one destructive and simplifying, the other -synthetic, constructive, or assimilating. This totality -of reactions constitutes nutrition. Hence the two -phases that it is convenient to consider in this function—<i>assimilation</i> -and <i>disassimilation</i>. This twofold -chemical movement or <i>metabolism</i> corresponding to -the two categories of vital phenomena, of destruction -(catabolism) and of synthesis (anabolism) is therefore -the chemical sign of vitality in all its forms. But it -is clear that disassimilation or organic destruction, -which is destined to furnish energy to the organism -for its different operations, reappears in the plan of -the general phenomena of nature. It is not specifically -vital in its principle. Assimilation, on the other -hand, is in this respect much more characteristic.</p> - -<p>To some physiologists nutrition is only assimilation. -Of the two aspects of metabolism they consider -only one, the most typical, <i>Ad-similare</i>, to assimilate, -to restore the substance borrowed from the ambient -medium, the alimentary substances, <i>similar</i> to living -matter, to make living matter of them, to increase -active protoplasm—this is indeed the most striking -phenomenon of vitality. To grow, to increase, to -expand, to invade, is the law of living matter. -Assimilation, nutrition in its essentials, is, according -to the definition of Ch. Robin, “the production by the -living being of a substance identical with its own.” -It is the act by which the living matter, the protoplasm -of a given being, is created.</p> - -<p><i>Permanence in Nutrition.</i>—Nutrition presents one -quite remarkable character—permanence. It is a vital -manifestation, a property if we look at it in the cell, -in the living substance, a function if we consider it in -the animal or in the plant as a whole, which is never<span class="pagenum" id="Page_229">[Pg 229]</span> -arrested. Its suspension involves <i>ipso facto</i> the suspension -of life itself. It is, in the words of Claude -Bernard, that property of nutrition “which, as long as -it exists in an element, compels us to believe that this -element is alive, and which, when it is absent, compels -us to believe that it is dead. It dominates all others -by its generality and its importance. In a word, it is -the absolute test of vitality.”</p> - -<p><i>Biological Energetics shows the Importance of -Nutrition.</i>—We have indicated in advance the reason -of its importance, showing that its two phases, disassimilation -and assimilation, are the energetic -condition of the two kinds of vital phenomena -which we can distinguish.</p> - -<p>Nutrition is a manufacture of protoplasm at the -expense of the materials of the cellular ambient -medium, which are assimilated—<i>i.e.</i>, made chemically -and physically similar to living matter and to the -reserves it stores up. This operation, which is -peculiarly chemical, is therefore indicated by the -borrowing of materials from the external world, a -borrowing which is always going on, because the -operation is permanent, and, let me add, because of -the continual rejection of the waste products of -this manufacture. Our formula is:—Nutrition is a -chemistry which persists.</p> - -<p><i>The Idea of the Vital Vortex is Erroneous.</i>—Here -the effect has hidden the cause from the eyes -of the biologists. They have been struck by the -incessant entry and exit, by the never-ceasing passage, -by the <i>cycle</i> of matter through the living being -without guessing its why and wherefore; and they -have taken as a picture of the living being a vortex -in which the essential form is maintained while the<span class="pagenum" id="Page_230">[Pg 230]</span> -matter, which is accessory, flows on without a check. -This is Cuvier’s <i>vital vortex</i>. But for what purpose -is this circulating matter used? They thought that -it was employed entirely for the reconstitution of -the living substance, continually and inevitably destroyed -by the vital Minotaur.</p> - -<p><i>Destruction of Reserve-stuff</i>.—Here again there is -a mistake. Really living substance is but little -destroyed, and consequently requires very little -renewal by the functional activity of the animal -machine. Its metabolism—destruction and renewal—is -in every case infinitely less than is supposed in -the classical image of the vital vortex. It is the -merit of physiologists, and particularly of Pflüger and -Chauveau, to have worked for nearly forty years -to establish this truth. They have proved it, at -least as far as the muscular tissue is concerned. -Protoplasm, properly so-called, is only destroyed -as the organs of a steam engine are destroyed—its -tubes, its boiler, its furnace. And it matters little. -We know that such an engine uses much coal, and we -know very little of its machinery and its metallic -frame. And so it is with the cell, the living machine. -A very small portion of the food introduced will be -assimilated in the living substance. By far the -greater part of it is destined to be worked up by the -protoplasm and placed in reserve under the form of -glycogen, albumen, and fat, etc.—<i>i.e.</i>, compounds -which are not the really living substance, the hereditary -protoplasm, but the products of its industry, just as -they are or may be the products of the industry of -the chemist working in his laboratory. They will be -expended for the purpose of furnishing the necessary -energy to the vital functional activity, muscular<span class="pagenum" id="Page_231">[Pg 231]</span> -contraction, secretion, heat, etc., just as coal is -expended to set the steam engine going. The proof -as far as the muscle is concerned does not stand -alone. There are other examples. In particular, -micrographic physiologists who have studied nervous -phenomena say that the anatomical elements of the -brain last indefinitely, and that they continue as they -are, without renewal from birth to death. The -permanence of the consciousness, be it said in -passing, is connected by them with the permanence -of the cerebral element (Marinesco).</p> - -<p>Thus destruction is very restricted. There is only -a very slight disassimilation of the living matter, -properly so-called, in the course of the vital functional -activity. We may even go farther than this experimental -fact. This is what Le Dantec has done -when he claims that there is even an assimilation, an -increase of the protoplasm. Strictly speaking, this -is possible, but there is no certain proof of it; and in -any case we cannot agree with him when he affirms -that the increase is the <i>direct result</i> of the functional -activity and blends with it in one single, unique -operation. We must, on the contrary, agree with -Claude Bernard that it is only a <i>consequence</i> of it, -that it is produced in consequence of the existence of -a bond of correlation between organic destruction and -assimilating synthesis.</p> - -<p>Why is there this bond? That is easily understood -if we reflect that the assimilating synthesis, an -operation of endothermic, chemical complexity, naturally -requires an exothermic counterpart, the organic -destruction which will set free this necessary energy.</p> - -<p><i>Formative Assimilation of Reserve-stuff. Formative -Assimilation of Protoplasm.</i>—It follows that<span class="pagenum" id="Page_232">[Pg 232]</span> -there are in nutritive assimilation itself two distinct -acts. The one consisting of the manufacture of -reserve-stuff is the more obvious but the less -specific; the other, really essential, is assimilation -properly so-called, the reconstitution of the protoplasm. -The former is indispensable to the production -of the most prominent acts of vitality—movement, -secretion, production of heat. If it is -suspended, functional activity is arrested. We get -<i>apparent death</i>, or <i>latent life</i>. But if the real assimilation -is arrested, we have <i>real death</i>.</p> - -<p>According to this there would be a fundamental -distinction between real and apparent death. The -former would be characterized by an <i>arrest of the -protoplasmic assimilation</i> which is externally indicated -by no sign. On the other hand, apparent death -would be characterized by <i>the arrest of the formation -and destruction of reserve-stuff</i>. It would be externally -manifested by two signs:—The suppression -of material exchanges with the medium (respiration, -alimentation) and the suppression of the functional -acts (production of movement, of heat, of electricity, -of glandular excretion).</p> - -<p>Such would be the most expedient test for apparent -or real death. The question occurs in the case of -grains of corn in Egyptian tombs, and also of -hibernating animals and reviviscent beings, and, in -general, in the case of what has been called the state -of <i>latent life</i>. But from the practical point of view -it is extremely difficult to apply this test and to -decide if the phenomena which are arrested in the -grain at maturity, in Leeuwenhoek’s tardigrada,<a id="FNanchor_18" href="#Footnote_18" class="fnanchor">[18]</a><span class="pagenum" id="Page_233">[Pg 233]</span> -and in the dried-up Anguillulidæ<a id="FNanchor_19" href="#Footnote_19" class="fnanchor">[19]</a> of Baker and -Spallanzani, in the encysted colpoda<a id="FNanchor_20" href="#Footnote_20" class="fnanchor">[20]</a> that a drop of -warm water will revive, in the animals exposed by -E. Yung and Pictet to a cold of more than a -100° C. below zero, are due to the general arrest of -the two forms of assimilation, or to the arrest of the -manufacture and utilization of reserve-stuff alone, or -finally, to the arrest of protoplasmic assimilation -alone. The latter, which is already very restricted -in beings in a normal condition whose growth is -terminated, may fall to the lowest degree in the -being which, having no functional activity, is assimilating -nothing. So that, to cut the question short, -the experimenter who measures the value of the -exchanges between the being and the medium has -seldom to do more than decide between little and -nothing. Hence his perplexity. But if experiment -hesitates, theory affirms: it admits <i>a priori</i> that the -movement of protoplasmic assimilation, an essential -sign of vitality, is neither checked nor renewed, but -proceeds continuously.</p> - -<p><i>Is Nutrition, the Assimilating Synthesis, interrupted?</i>—Nevertheless, -there are many reasons for -suspending all judgment as to this interpretation. -It is questioned by most biologists. According to -A. Gautier, the preserved grain of corn and the dried -up rotifera are not really alive; they are like clocks -in working order, ready to tell the time, but awaiting -in absolute repose the first vibration which will set -them going. As for the grain, it is the air, heat, and<span class="pagenum" id="Page_234">[Pg 234]</span> -moisture which supply the first impulse. In other -words, the organization proper to the manifestation of -life remains, but there is no life. The so-called -arrested life is not a life.</p> - -<p>It must be said, however, that the majority of -physiologists refuse to accept this interpretation. -They believe in an attenuation of the nutritive -synthesis and not in its complete destruction. They -think that this total suppression would be contrary -to current ideas relative to the perpetuity of the -protoplasm and the limited duration of the living -element. The natural medium is variable, and even -the mineral cannot remain eternally fixed. Still less -is perennity a property of the living being. If -ordinary life is for each individual of limited duration, -the arrested life must also be of limited duration. -We cannot believe that after an indefinitely prolonged -sleep the grain of corn, or the paste-eel, or the -colpoda, emerging from their torpor can resume their -existence, like the Sleeping Beauty, at the point at -which it was interrupted, and thus pass with a bound, -as it were, through the centuries.</p> - -<p>In fact the maintenance of the vitality of grains -of corn from the Egyptian tombs and their aptitude -to germinate after thousands of years are only fables -or the result of imposture. Maspero, in a letter -addressed to M. E. Griffon on the 15th July 1901, -has clearly summed up the situation by saying that -the grains of corn bought from the fellahs almost -always germinate, but that this is never the case with -those that the experimenter himself takes from the -tombs.</p> - -<p>To sum up, we must use the same language of -nutrition and of life, of their uninterrupted progress,<span class="pagenum" id="Page_235">[Pg 235]</span> -of their continuity, of their permanence, of their -activity, and of their slackening. Living matter is -always growing, much or little, slowly or quickly, -in its reserve-stuff or in its protoplasm, for expenditure -or accumulation. This inevitability of growth defines -it, characterizes it, and sums up its activity. Development -and the evolution of growth are consequences or -aspects of nutrition.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_236">[Pg 236]</span></p> - -<h2 class="nobreak" id="BOOK_IV">BOOK IV.<br /> - - -<small>THE LIFE OF MATTER.</small></h2></div> - - -<p class="prel">Summary: Chap. I. Universal life—Opinions of philosophers -and poets—Continuity between brute and living bodies—Origin -of this principle.—Chap. II. Origin of brute matter -in living matter.—Chap. III. Organization and chemical -composition of brute and living bodies.—Chap. IV. Evolution -and transformation of brute and living bodies.—Chap. -V. Possession of a specific form—Living bodies and -crystals—Cicatrization.—Chap. VI. Nutrition in the living -body and in the crystal.—Chap. VII. Generation in brute -and in living bodies—Spontaneous generation.</p> - - - -<p><i>Apparent Differences between Living and Brute -Bodies. The Two Kingdoms.</i>—It seems at first -impossible that there should be any essential -similarity between an inanimate object and a living -being. What resemblance can be discovered between -a stone, a lion, and an oak? A comparison of the -inert and immovable pebble with the leaping animal, -and with the plant extending its foliage gives an -impression of vivid contrast. Between the organic -and the inorganic worlds there seems to be an abyss. -The first impressions we receive confirm this view; -superficial investigation furnishes arguments for it. -There is thus aroused in the mind of the child, and -later in that of the man, a sharply marked distinction -between the natural objects of the mineral kingdom -on the one hand, and those of the two kingdoms of -living beings on the other.</p> - -<p><span class="pagenum" id="Page_237">[Pg 237]</span></p> - -<p>But a more intimate knowledge daily tends to -throw doubt upon the rigour or the absolute character -of such a distinction. It shows that brute matter can -no longer be placed on one side and living beings on -the other. Scientists deliberately speak of “the life -of matter,” which seems to the average man a contradiction -in terms. They discover in certain classes -of mineral bodies almost all the attributes of life. -They find in others fainter, but still recognizable -indications of an undeniable relationship.</p> - -<p>We propose to pass in review these analogies and -resemblances, as has already been done in a fairly -complete manner by Leo Errera, C. E. Guillaume, -L. Bourdeau, Ed. Griffon, and others. We will consider -the fine researches of Rauber, of Ostwald, -and of Tammann upon crystals and crystalline germs—researches -which are merely a continuation of those -of Pasteur and of Gernez. These show that crystalline -bodies are endowed with the principal attributes -of living beings—<i>i.e.</i>, a rigorously defined form; an -aptitude for acquiring it, and for re-establishing it by -repairing any mutilations that may be inflicted upon -it; nutritive growth at the expense of the mother -liquor which constitutes its culture medium; and, -finally—a still more incredible property—all the -characteristics of reproduction by generation. Other -curious facts observed by skilful physicists—W. -Roberts-Austen, W. Spring, Stead, Osmond, Guillemin, -Charpy, C. E. Guillaume—show that the immutability -even of bodies supposed to be the most rigid -of all, such as glass, the metals, steel, and brass, is -apparent rather than real. Beneath the surface of the -metal that seems to us inert there is a swarming -population of molecules, displacing each other, moving<span class="pagenum" id="Page_238">[Pg 238]</span> -about, and arranging themselves so as to form definite -figures, and assuming forms adapted to the conditions -of the environment. Sometimes it is years before -they arrive at the state of ultimate and final equilibrium—which -is that of eternal rest.</p> - -<p>However, in order to understand these facts and -their interpretations, it is necessary to pass in review -the fundamental characteristics of living beings. It -will be shown that these very characteristics are found -in inanimate matter.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_239">[Pg 239]</span></p> - -<h3 class="nobreak" id="CHAPTER_I_4">CHAPTER I.<br /> - -<small>UNIVERSAL LIFE. OPINIONS OF PHILOSOPHERS -AND POETS.</small></h3></div> - - -<p class="prel">§ 1. Primitive beliefs; the ideas of poets.—§ 2. Opinions of -philosophers—Transition from brute to living bodies—The -principle of continuity: continuity by transition: continuity -by summation—Ideas of philosophers as to sensibility and -consciousness in brute bodies—The general principle of -homogeneity—The principle of continuity as a consequence -of the principle of homogeneity.</p> - - -<h4>§ 1. <span class="smcap">Primitive Beliefs. Ideas of the Poets.</span></h4> - -<p>The teaching of science as to the analogies between -brute bodies and living bodies accords with the conceptions -of the philosophers and the fancies of the -poets. The ancients held that all bodies in nature -were the constituent parts of a universal organism, -the macrocosm, which they compared to the human -microcosm. They attributed to it a principle of -action, the <i>psyche</i>, analogous to the vital principle, -and this psyche directed phenomena; and also an -intelligent principle, the <i>nous</i>, analogous to the soul, -and the <i>nous</i> served for the comprehension of phenomena. -This universal life and this universal soul -played an important part in their metaphysical -systems.</p> - -<p><span class="pagenum" id="Page_240">[Pg 240]</span></p> - -<p>It was the same with the poets. Their tendency -has always been to attribute life to Nature, so as to -bring her into harmony with our thoughts and feelings. -They seek to discover the life or soul hidden -in the background of things.</p> - -<div class="poetry-container"> -<div class="poetry"> - <div class="stanza"> - <div class="verse indent0">“Hark to the voices. Nothing is silent.</div> - </div> - <div class="stanza"> - <div class="verse indent0">Winds, waves, and flames, trees, reeds, and rocks</div> - <div class="verse indent0">All live; all are instinct with soul.”</div> - </div> -</div> -</div> - -<p>After making proper allowance for emotional -exaggeration, ought we to consider these ideas as the -prophetic divination of a truth which science is only -just beginning to dimly perceive? By no means. As -Renan has said, this universal animism, instead of -being a product of refined reflection, is merely a -legacy from the most primitive of mental processes, -a residue of conceptions belonging to the childhood -of humanity. It recalls the time when men conceived -of external things only in terms of themselves; when -they pictured each object of nature as a living being. -Thus, they personified the sky, the earth, the sea, the -mountains, the rivers, the fountains, and the fields. -They likened to animate voices the murmur of the -forest:—</p> - -<div class="poetry-container"> -<div class="poetry"> - <div class="stanza"> - <div class="verse indent0">“ ... The oak chides and the birch</div> - <div class="verse indent0">Is whispering....</div> - <div class="verse indent0">And the beech murmurs....</div> - <div class="verse indent0">The willow’s shiver, soft and faint, sounds like a word.</div> - <div class="verse indent0">The pine-tree utters mysterious moans.”</div> - </div> -</div> -</div> - -<p>For primitive man, as for the poet of all times, -everything is alive, and every sound is due to a being -with feelings similar to our own. The sighing of the -breeze, the moan of the wave upon the shore, the<span class="pagenum" id="Page_241">[Pg 241]</span> -babbling of the brook, the roaring of the sea, and the -pealing of the thunder are nothing less than sad, -joyous, or angry living voices.</p> - -<p>These impressions were embodied in ancient -mythology, the graceful beauty of which does not -conceal its inadequacy. Then they passed into -philosophy and approached the realm of science. -Thales believed that all bodies in nature were -animate and living. Origen considered the stars as -actual beings. Even Kepler himself attributed to the -celestial bodies an internal principle of action, which, -it may be said in passing, is contrary to the law of -the inertia of matter, which has been wrongly ascribed -to him instead of to Galileo. The terrestrial globe -was, according to him, a huge animal, sensitive to -astral influences, frightened at the approach of the -other planets, and manifesting its terror by tempests, -hurricanes, and earthquakes. The wonderful flux and -reflux of the ocean was its breathing. The earth had -its blood, its perspiration, its excretions; it also had -its foods, among which was the sea water which it -absorbs by numerous channels. It is only fair to add -that at the end of his life Kepler retracted these vague -dreams, ascribing them to the influence of J. C. -Scaliger. He explained that by the soul of the -celestial bodies he meant nothing more than their -motive force.</p> - - -<h4>§ 2. <span class="smcap">Opinion of the Philosophers.</span></h4> - -<p><i>Transition from Brute to Living Bodies.</i>—The -lowering of the barrier between brute bodies and -living bodies began with those philosophers who<span class="pagenum" id="Page_242">[Pg 242]</span> -introduced into the world the great principles of -continuity and evolution.</p> - -<p><i>The Principle of Continuity.</i>—First and foremost -we must mention Leibniz. According to the teaching -of that illustrious philosopher, as interpreted by M. -Fouillée, “there is no inorganic kingdom, only a great -organic kingdom, of which mineral, vegetable, and -animal forms are the various developments.... -Continuity exists everywhere throughout the world; -everywhere is life and organization. Nothing is -dead; life is universal.” It follows that there is no -interruption or break in the succession of natural -phenomena; that everything is gradually developed; -and finally, that the origin of the organic being must -be sought in the inorganic. Life, properly so called, -has not, in fact, always existed on the surface of the -globe. It appeared at a certain geological epoch, in -a purely inorganic medium, by reason of favourable -conditions. The doctrine of continuity compels us, -however, to admit that it pre-existed on the globe -under some rudimentary form.</p> - -<p>The modern philosophers who are imbued with -these principles, MM. Fouillée, L. Bourdeau, and A. -Sabatier, express themselves in similar language. -“Dead matter and living matter are not two absolutely -different entities, but represent two forms of -the same matter, differing only in degree, sometimes -but slightly.” When it is only a matter of degree, it -cannot be held that these views are opposed. Inequalities -must not be interpreted as contrary attributes, -as when the untrained mind considers heat -and cold as objective states, qualitatively opposed -to each other.</p> - -<p><i>Continuity by Transition.</i>—The argument which<span class="pagenum" id="Page_243">[Pg 243]</span> -leads us to remove the barrier between the two kingdoms, -and to consider minerals as endowed with a -sort of rudimentary life, is the same as that which -compels us to admit that there is no fundamental -difference between natural phenomena. There are -transitions between what lives and what does not, -between the animate being and the brute body. And -in the same way there are transitions between what -thinks and what does not think, between what is -thought and what is not thought, between the conscious -and the unconscious. This idea of insensible -transition, of a continuous path between apparent -antitheses, at first arouses an insuperable opposition -in minds not prepared for it by a long comparison of -facts. It is slowly realized, and finally is accepted by -those who, in the world of things, follow the infinity -of gradations presented by natural phenomena. The -principle of continuity comes at last to constitute, as -one may say, a mental habit. Thus the man of science -may be led, like the philosopher, to entertain the -idea of a rudimentary form of life animating matter. -He may, like the philosopher, be guided by this idea; -he may attribute <i>a priori</i> to brute matter all the really -essential qualities of living beings. But this must -be on the condition that, assuming these properties to -be common, he must afterwards demonstrate them by -means of observation and experiment. He must show -that molecules and atoms, far from being inert and -dead masses, are in reality active elements, endowed -with a kind of inferior life, which is manifested by all -the transformations observed in brute matter, by -attractions and repulsions, by movements in response -to external stimuli, by variations of state and of -equilibrium; and finally, by the systematic methods<span class="pagenum" id="Page_244">[Pg 244]</span> -according to which these elements group themselves, -conforming to those definite types of structure by -means of which they produce different species of -chemical compounds.</p> - -<p><i>Continuity by Summation.</i>—The idea of summation -leads by another path to the same result. It is -another form of the principle of continuity. A sum -total of effects, obscure and indistinct in themselves, -produces a phenomenon appreciable, perceptible, and -distinct, apparently, but not really, heterogeneous in -its components. The manifestations of atomic or -molecular activity thus become manifestations of vital -activity.</p> - -<p>This is another consequence of the teaching of -Leibniz. For, according to his philosophical theory, -individual consciousness, like individual life, is the -collective expression of a multitude of elementary -lives or consciousnesses. These elements are inappreciable -because of their low degree, and the real -phenomenon is found in the sum, or rather the -<i>integral</i>, of all these insensible effects. The elementary -consciousnesses are harmonized, unified, -integrated into a result that becomes manifest, just -as “the sounds of the waves, not one of which would -be heard if by itself, yet, when united together and -perceived at the same instant, become the resounding -voice of the ocean.”</p> - -<p><i>Ideas of the Philosophers as to Sensibility and Consciousness -in Brute Bodies.</i>—The philosophers have -gone still further in the way of analogies, and have -recognized in the play of the forces of brute matter, -particularly in the play of chemical forces, a mere -rudiment of the appetitions and tendencies that regulate, -as they believe, the functional activity of living<span class="pagenum" id="Page_245">[Pg 245]</span> -beings—a trace, as it were, of their sensibility. To -them reactions of matter indicate the existence of a -kind of <i>hedonic consciousness</i>—<i>i.e.</i>, a consciousness -reduced simply to a distinction between comfort and -discomfort, a desire for good and repulsion from evil, -which they suppose to be the universal principle of all -activity. This was the view held by Empedocles in -antiquity; it was that of Diderot, of Cabanis, and, in -general, of the modern materialistic school, eager to -find, even in the lowest representatives of the -inorganic world, the first traces of the vitality and -intellectual life which blossom out at the top of the -scale in the living world.</p> - -<p>Similar ideas are clearly seen in the early history of -all natural sciences. It was this same principle of -appetition, or of love and of repulsion or hate that, -under the names of affinity, selection, and incompatibility, -was thought to direct the transformations of -bodies when chemistry first began; when Boerhaave, -for example, compared chemical combinations to -voluntary and conscious alliances, in which the -respective elements, drawn together by sympathy, -contracted appropriate marriages.</p> - -<p><i>General Principle of the Homogeneity of the Complex -and its Components.</i>—The assimilation of brute bodies -to living bodies, and of the inorganic kingdom to the -organic, was, in the mind of these philosophers, the -natural consequence of positing <i>a priori</i> the principles -of continuity and evolution. There is, however, a -principle underlying these principles. This principle -is not expressed explicitly by the philosophers; it is -not formulated in precise terms, but is more or less -unconsciously implied; it is everywhere applied. It, -however, may be clearly seen behind the apparatus of<span class="pagenum" id="Page_246">[Pg 246]</span> -philosophical argument It is the assertion that no -arrangement or combination of elements can put -forth any new activity essentially different from the -activities of the elements of which it is composed. -Man is living clay, say Diderot and Cabanis; and, -on the other hand, he is a thinking being. <i>As it is -impossible to produce that which thinks from that which -does not think</i>, the clay must possess a rudiment of -thought. But is there not another alternative? May -not the new phenomenon, thought, be the effect of -the arrangement of this clay? If we exclude this -alternative, we must then consider arrangement and -organization as incapable of producing in arranged -and organized matter a new property different from -that which it presented before such arrangement. -Living protoplasm, says another, is merely an -assemblage of brute elements; “these brute elements -must therefore possess a rudiment of life.” This is -the same implied supposition which we have just -considered; if life is not the basis of each element, it -cannot result from their simple assemblage.</p> - -<p>Man and animals are combinations of atoms, says -M. le Dantec. It is more natural to admit that -human consciousness is the result of the elementary -consciousness of the constituent atoms than to consider -it as resulting from construction by means -of elements with no consciousness. “Life,” says -Haeckel, “is universal; we could not conceive of its -existence in certain aggregates of matter if it did not -belong to their constituent elements.” Here the -postulate is almost expressed.</p> - -<p>The argument is always the same; even the same -words are used: the fundamental hypothesis is the -same; only it remains more or less unexpressed,<span class="pagenum" id="Page_247">[Pg 247]</span> -more or less unperceived. It may be stated as -follows:—Arrangement, assemblage, construction, and -aggregation are powerless to bring to light in the -complex anything new and essentially heterogeneous -to what already exists in the elements. Reciprocally, -grouping reveals in a complex a property and -character which is the gradual development of an -analogous property and character in the elements. -It is in this sense that there exists a collective soul in -crowds, the psychology of which has been discussed -by M. G. Le Bon. In the same way, many sociologists, -adopting the views advanced by P. de Lilienfeld -in 1865, attribute to nations a formal individuality, -after the type of that possessed by each of their -constituent members. M. Izolet considers society -as an organism, which he calls a “hyperzoan.” -Herbert Spencer has developed the comparison of -the collective organism with the individual organism, -insisting on their resemblances and differences. Th. -Ribot has dwelt, in particular, on the resemblances.</p> - -<p>The postulate that we have clearly stated here is -accepted by many as an axiom. But it is not an -axiom. When we say that there is nothing in the -complex that cannot be found in the parts, we think -we are expressing a self-evident truth; but we are, -in fact, merely stating an hypothesis. It is assumed -that arrangement, aggregation, and complicated and -skilful grouping of elements can produce nothing -really new in the order of phenomena. And this is -an assertion that requires verification in each particular -case.</p> - -<p><i>The Principle of Continuity, a Consequence of the -Preceding.</i>—Let us apply this principle to the beings -in nature. All beings in nature are, according to<span class="pagenum" id="Page_248">[Pg 248]</span> -current ideas, arrangements, aggregates, or groupings -of the same universal matter, that is to say, of the -same simple chemical bodies. It results from the -preceding postulate that their activities can only differ -in degree and form, and not fundamentally. There -is no essential difference of nature between the -activities of various categories of beings, no heterogeneity, -no discontinuity. We may pass from one to -another without coming to an hiatus or impassable -gulf. The law of continuity thus appears as a simple -consequence of the fundamental postulate. And so -it is with the law of evolution, for evolution is merely -continuity of action.</p> - -<p>Such are the origins of the philosophical doctrine -which universalizes life and extends it to all bodies -in nature.</p> - -<p>It may be remarked that this doctrine is not -confined to any particular school or sect. Leibniz -was by no means a materialist, and he endowed his -mundane elements, his <i>monads</i>, not only with a sort -of life, but even with a sort of soul. Father Boscovitch, -Jesuit as he was, and professor in the college of -Rome, did not deny to his <i>indivisible points</i> a kind of -inferior vitality. St. Thomas, too, the angelical -doctor, attributed, according to M. Gardair, to -inanimate substances a certain kind of activity, -inborn inclinations, and a real appetition towards -certain acts.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_249">[Pg 249]</span></p> - -<h3 class="nobreak" id="CHAPTER_II_4">CHAPTER II.<br /> - -<small>ORIGIN OF BRUTE MATTER IN LIVING MATTER.</small></h3></div> - - -<p class="prel">Spontaneous generation: an episode in the history of the -globe—Verification of the identity between brute and -living matter—Slow identification—Rapid identification—Contrary -opinion—Hypothesis of cosmozoa; cosmic -panspermia—Hypothesis of pyrozoa.</p> - - -<p>There should be two ways of testing the doctrine of -the essential identity of brute and living matter—one -slow and more laborious, the other more rapid -and decisive.</p> - -<p><i>Identification of the Two Matters, Brute and -Living.</i>—The laborious method, which we will be -obliged to follow, consists in the attentive examination -of the various activities by which life is -manifested, and in finding more or less crude -equivalents for them in all brute beings, or in certain -of them.</p> - -<p><i>Rapid Verification. Spontaneous Generation.</i>—The -rapid and decisive method, which, unhappily, is -beyond our resources, would consist in showing unquestionable, -clearly marked life, the superior life, -arising from the kind of inferior life that is attributed -to matter in general. It would be necessary completely -to construct in all its parts, by a suitable -combination of inorganic materials, a single living -being, even the humblest plant or the most rudi<span class="pagenum" id="Page_250">[Pg 250]</span>mentary -animal. This would indeed be an irrefutable -proof that the germs of all vital activity are contained -in the molecular activity of brute bodies, and that -there is nothing essential to the latter that is not -found in the former.</p> - -<p>Unhappily this demonstration cannot be given. -Science furnishes no example of it, and we are forced -to have recourse to the slow method.</p> - -<p>The question here involved is that of spontaneous -generation. It is well known that the ancients -believed in spontaneous generation, even for animals -high in the scale of organization. According to -Van Helmont, mice could be born by some incomprehensible -fermentation in dirty linen mixed with -wheat. Diodorus speaks of animal forms which were -seen to emerge, partly developed, from the mud of -the Nile. Aristotle believed in the spontaneous birth -of certain fishes. This belief, though rejected as to -the higher forms, was for a long time held with -regard to the lower forms of animals, and to insects—such -as the bees which the shepherd of Virgil saw -coming out from the flanks of the dead bullock—flies -engendered in putrefying meat, fruit worms and -intestinal worms; finally, with regard to infusoria -and the most rudimentary vegetables. The hypothesis -of the spontaneous generation of the living -being at the expense of the materials of the ambient -medium has been successively driven from one -classificatory group to another. The history of the -sciences of observation is also a history of the confutation -of this theory. Pasteur gave it the finishing -stroke, when he showed that the simplest microorganisms -obeyed the general law which declares -that the living being is formed only by <i>filiation</i>—that<span class="pagenum" id="Page_251">[Pg 251]</span> -is to say, by the intervention of a pre-existing living -organism.</p> - -<p><i>Spontaneous Generation an Episode in the History -of the Globe.</i>—Though we have been unable to effect -spontaneous generation up to the present, it has been -referred by Haeckel to a more or less distant past, to -the time when the cooling of the globe, the solidification -of its crust, and the condensation of aqueous -vapour upon its surface created conditions compatible -with the existence of living beings similar to those -with which we are acquainted. Lord Kelvin has -fixed these geological events as occurring from twenty -to forty million years ago. Then circumstances -became propitious for the appearance of the first -organisms, whence were successively derived those -which now people the earth and the waters.</p> - -<p>Circumstances favourable to the appearance of the -first beings apparently occurred only in a far distant -past; but most physiologists admit that if we knew -exactly these circumstances, and could reproduce -them, we might also expect to produce their effect—namely, -the creation of a living being, formed in all -its parts, developed from the inorganic kingdom. -To all those who held this view the impotence of -experiment at the present time is purely temporary. -It is comparable to that of primitive men before the -time of Prometheus; they, not knowing how to -produce fire, could only get it by transmitting it -from one to another. It is due to the inadequacy -of our knowledge and the weakness of our means; it -does not contradict the possibility of the fact.</p> - -<p><i>Contrary Opinion. Life did not Originate on our -Globe.</i>—But all biologists do not share this opinion. -Some, and not the least eminent, hold it to be an<span class="pagenum" id="Page_252">[Pg 252]</span> -established fact that it is impossible for life to arise -from a concurrence of inorganic materials and forces. -This was the opinion of Ferdinand Cohn, the great -botanist; of H. Richter, the Saxon physician, and of -W. Preyer, a physiologist well known from his -remarkable researches in biological chemistry. -According to these scientists, life on the surface of -the globe cannot have appeared as a result of the -reactions of brute matter and the forces that continue -to control it.</p> - -<p>According to F. Cohn and PI. Richter, life had no -beginning on our planet. It was transported to the -earth from another world, from the cosmic medium, -under the form of cosmic germs, or <i>cosmozoa</i>, more -or less comparable to the living cells with which we -are acquainted. They may have made the journey -either enclosed in meteorites, or floating in space in -the form of cosmic dust. The theory in question -has been presented in two forms:—<i>The Hypothesis of -Meteoric Cosmozoa</i>, by a French writer, the Count -de Salles-Guyon; and that of <i>cosmic panspermia</i> -brought forward in 1865 and 1872 by F. Cohn and -H. Richter.</p> - -<p><i>Hypothesis of the Cosmozoa.</i>—The hypothesis of -the cosmozoa, living particles, protoplasmic germs -emanating from other worlds and reaching the earth -by means of aerolites, is not so destitute of probability -as one might at first suppose. Lord Kelvin and -Helmholtz gave it the support of their high authority. -Spectrum analysis shows in cometary nebulæ the -four or five lines characteristic of hydro-carbons. -Cosmic matter, therefore, contains compounds of -carbon, substances that are especially typical of -organic chemistry. Besides, carbon and a sort of<span class="pagenum" id="Page_253">[Pg 253]</span> -humus have been found in several meteorites. To -the objection that these aerolites are heated while -passing through our atmosphere, Helmholtz replies -that this elevation of temperature may be quite -superficial and may allow micro-organisms to subsist -in their interior. But other objections retain their -force:—First, that of M. Verworn, who considers the -hypothesis of cosmic germs as inconsistent with the -laws of evolution; and that of L. Errera, who denies -that the conditions necessary for life exist in interplanetary -bodies.</p> - -<p><i>Hypothesis of Cosmic Panspermia.</i>—Du Bois-Reymond -has given the name of <i>cosmic panspermia</i> -to a theory very similar to the preceding, formulated -by F. Cohn in 1872. The first living germs arrived -on our globe mingled with the cosmic dust that -floats in space and falls slowly to the surface of the -earth. L. Errera observes that if they escape by -this gentle fall the dangerous heating of meteorites, -they still remain exposed to the action of the photic -rays, which is generally destructive to germs.</p> - -<p><i>Hypothesis of Pyrozoa.</i>—W. Preyer declined to -accept this cosmic transmigration of the simplest -living beings, nor would he allow the intervention of -other worlds into the history of our own. Life, -according to him, must have existed from all time, -even when the globe was an incandescent mass. -But it was not the same life as at present. Vitality -must have undergone many profound changes in the -course of ages. The <i>pyrozoa</i>, the first living beings, -vulcanians, were very different from the beings of -the present day that are destroyed by a slight -elevation of temperature. No doubt this theory of -pyrozoa, proposed by W. Preyer in 1872, seems<span class="pagenum" id="Page_254">[Pg 254]</span> -quite chimerical, and akin to Kepler’s dreamy visions. -But in a certain way it accords with contemporary -ideas concerning the life of <i>matter</i>. It is related to -them by the evolution which it implies in the materials -of the terrestrial globe.</p> - -<p>According to Preyer, primitive life existed in fire. -Being igneous masses in fusion, the pyrozoa lived -after their own manner; their vitality, slowly modified, -assumed the form which it presents to-day. Yet, in -this profound transformation their number has not -varied, and the total quantity of life in the universe -has remained unchanged.</p> - -<p>Here we recognize the ideas of Buffon. These -cosmozoa, these pyrozoa, have a singular resemblance -to the <i>organic molecules</i> of “live matter” of the -illustrious naturalist—distributed everywhere, indestructible, -and forming living structures by their -concentration.</p> - -<p>But we must leave these scientific or philosophical -theories, and come to arguments based upon facts.</p> - -<p>It is in a spirit quite different from that of the -poets, the metaphysicians, and the more or less -philosophical scientists that the science of our days -looks at the more or less obscure vitality of inanimate -bodies. It claims that we may recognize in them, -in a more or less rudimentary state, the action -of the factors which intervene in the case of living -beings, the manifestation of the same fundamental -properties.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_255">[Pg 255]</span></p> - -<h3 class="nobreak" id="CHAPTER_III_4">CHAPTER III.<br /> - -<small>ORGANIZATION AND CHEMICAL COMPOSITION OF -LIVING AND BRUTE MATTER.</small></h3></div> - - -<p class="prel">Laws of the organization and of the chemical composition of -living beings—Relative value of these laws; vital phenomena -in crushed protoplasm—Vital phenomena in brute -bodies.</p> - - -<p><i>Enumeration of the Principal Characters of Living -Beings.</i>—The programme which we have just sketched -compels us to look in the brute being for the properties -of living beings. What, then, are, in fact, the -characteristics of an authentic, complete, living being? -What are its fundamental properties? We have -enumerated them above as follows:—A certain -chemical composition, which is that of living matter; -a structure or organization; a specific form; an -evolution which has a duration, that of life, and an -end, death; a property of growth or nutrition; a -property of reproduction. Which of these characters -counts for most in the definition of life? Are they -all equally necessary? If some of them were wanting, -would that justify the transference of a being, who -might possess the rest, from the animate world to -that of minerals? This is precisely the question that -is under consideration.</p> - -<p><i>Organization and Chemical Composition of Living -Beings.</i>—All that we know concerning the constitution<span class="pagenum" id="Page_256">[Pg 256]</span> -of living matter and its organization is summed up in -the laws of the <i>chemical unity</i> and the <i>morphological -unity of living beings</i> (v. Book III.). These laws seem -to be a legitimate generalization from all the facts -observed. The first states that the phenomena of -life are manifested only in and through living matter, -protoplasm—<i>i.e.</i>, in and through a substance which -has a certain chemical and physical composition. -Chemically it is a proteid complexus with a hexonic -nucleus. Physically it shows a frothy structure -analogous to that resulting from the mixture of two -granular, immiscible liquids, of different viscosities. -The second law states that the phenomena of life -can only be maintained in a protoplasm which has -the organization of the complete cell, with its cellular -body and nucleus.</p> - -<p><i>Relative Value of these Laws. Exceptions.</i>—What -is the signification of these laws of the chemical -composition and organization of living beings? -Evidently that life in all its plenitude can only exist -and be perpetuated under their protection. If these -laws were absolute, if it were true that no life were -possible but in and through albuminous protoplasm, -but in and through the cell, the problem of “the life -of matter” would be decided in the negative.</p> - -<p>May it not happen, however, that fragmentary and -incomplete vital manifestations, progressive traces -of a true life, may occur under different conditions; -for example, in matter which is not protoplasm, and -in a body which has a structure differing from that -of a cell—that is to say, in a being which would be -neither animal nor plant? We must seek the answer -to this question by an appeal to experiment.</p> - -<p>Without leaving the animal and vegetable king<span class="pagenum" id="Page_257">[Pg 257]</span>doms—<i>i.e.</i>, -real living beings—we already see less -rigour in the laws governing chemical constitution -and cellular organization.</p> - -<p>Experiments in merotomy—<i>i.e.</i>, in amputation—carried -out on the nervous element by Waller, on -infusoria by Brandt, Gruber, Balbiani, Nussbaum, -and Verworn, show us the necessity of the presence -of the cellular body and the nucleus—<i>i.e.</i>, of the integrity -of the cell. But they also teach us that when -that integrity no longer exists death does not immediately -follow. A part of the vital functions continues -to be performed in denucleated protoplasm, in a cell -which is mutilated and incomplete.</p> - -<p><i>Vital Phenomena in Crushed Protoplasm.</i>—It is -true also that grinding and crushing suppress the -greater part of the functions of the cell. But tests -with pulps of various organs and with those of certain -yeasts also show that protoplasm, even though ground -and disorganized, cannot be considered as inert, and -that it still exhibits many of its characteristic phenomena; -for example, the production of diastases, the -specific agents of vital chemistry. Finally, while we -do not know enough about the actions of which the -secondary elements of protoplasm—its granulations, -its filaments—are capable, which this or that method -of destruction may bring to light, at least we know -that actions of this kind exist.</p> - -<p>To sum up, we are far from being able to deny that -rudimentary, isolated vital acts may be produced by -the various bodies that result from the dismemberment -of protoplasm. The integrity of the cellular -organization, even the integrity of protoplasm itself, -are therefore not indispensable for these partial -manifestations of vitality.</p> - -<p><span class="pagenum" id="Page_258">[Pg 258]</span></p> - -<p>Besides, biologists admit that there exist within -the protoplasm aliquot parts, elements of an -inferior order, which possess special activities. -These secondary elements must have the principle -of their activity within themselves. Such are the -<i>biophors</i> to which Weismann attributes the vital -functions of the cell, nutrition, growth, and multiplication. -If there are biophors within the cell, we -may imagine them outside the cell, and since they -carry within themselves the principle of their activity -they may exercise it in an independent manner. -Unhappily the biophors, and other constituent elements -of that kind, are purely hypothetical. They -are like Darwin’s gemmules, Altmann’s bioblasts, and -the pangens of De Vries. They have no relation to -facts of observation and to real existence.</p> - -<p><i>Vital Phenomena in Brute Bodies.</i>—There is no -doubt that certain phenomena of vitality may occur -outside of the cellular atmosphere. And carrying -this further, we may admit that they may be produced -in certain slightly organized bodies (crushed -cells), and then in certain unorganized bodies in -certain brute beings. In every case it is certain that -effects are produced at any rate similar to those which -are characteristic of living matter. It is for observation -and experiment to decide as to the degree of similarity, -and their verdict is that the similarity is complete. -The crystals and the crystalline germs studied by -Ostwald and Tammann are the seat of phenomena -which are quite comparable to those of vitality.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_259">[Pg 259]</span></p> - -<h3 class="nobreak" id="CHAPTER_IV_4">CHAPTER IV.<br /> - -<small>EVOLUTION AND MUTABILITY OF LIVING MATTER -AND BRUTE MATTER.</small></h3></div> - - -<p class="prel">Supposed immobility of brute bodies—Mobility and mutability -of the sidereal world.—§ 1. The movement of particles and -molecules in brute bodies—The internal movements of -brute bodies—Kinetic conception of molecular motion—Reality -of the motion of particles—Comparison of the -activity of particles with vital activity.—§ 2. Brownian -movement—Its existence—Its character—Its independence -of the nature of the bodies and of the nature of the environment—Its -indefinite duration—Its independence of external -conditions—The Brownian movement must be the first -stage of molecular motion.—§ 3. Motion of particles—Migration -of material particles—Migration under the -action of weight; of diffusion; of electrolysis; of mechanical -pressure.—§ 4. Internal activity of alloys—Their structure—Changes -produced by deforming agencies—Slow return to -equilibrium—Residual effect—Effect of annealing; effect -of stretching—Nickel steel—Colour photography—Conclusion—Relations -of the environment to the living or brute -matter.</p> - - -<p>One of the most remarkable characteristics of a living -being is its evolution. It undergoes a continuous -change. It starts from something very small; it -assumes a configuration and grows; in most cases -it declines and disappears, having followed a course -which may be predicted—a sort of ideal trajectory.</p> - -<p><i>Supposed Immobility of Brute Bodies.</i>—It may be -asked whether this evolution, this directed mobility,<span class="pagenum" id="Page_260">[Pg 260]</span> -is so exclusively a feature of the living being as it -appears, and if many brute bodies do not present -something analogous to it. We may answer in no -uncertain tones.</p> - -<p>Bichat was wrong when he contrasted in this -respect brute bodies with living bodies. Vital -properties, he said, are temporary; it is their nature -to be exhausted; in time they are used up in the -same body. Physical properties, on the contrary, are -eternal. Brute bodies have neither a beginning nor -an inevitable end, neither age, nor evolution; they -remain as immutable as death, of which they are the -image.</p> - -<p><i>Mobility and Mutability of the Sidereal World.</i>—This -is not true, in the first place, of the sidereal -bodies. The ancients held the sidereal world to be -immutable and incorruptible. The doctrine of the -incorruptibility of the heavens prevailed up to the -seventeenth century. The observers who at that -epoch directed towards the heavens the first telescope, -which Galileo had just invented, were struck with -astonishment at discovering a change in that celestial -firmament which they had hitherto believed incorruptible, -and at perceiving a new star that appeared -in the constellation Ophiuchus. Such changes no -longer surprise us. The cosmogonic system of -Laplace has become familiar to all cultivated minds, -and every one is accustomed to the idea of the continual -mobility and evolution of the celestial world. -“The stars have not always existed,” writes M. Faye; -“they have had a period of formation; they will -likewise have a period of decline, followed by final -extinction.”</p> - -<p>Thus all the bodies of inanimate nature are not<span class="pagenum" id="Page_261">[Pg 261]</span> -eternal and immutable; the celestial bodies are -eminently susceptible of evolution, slow indeed with -that we observe on the surface of our globe; but this -disproportion, corresponding to the immensity of -time and of cosmic spaces as compared with terrestrial -measurements, should not mislead us as to the -fundamental analogy of the phenomena.</p> - - -<h4>§ 1. <span class="smcap">The Movement of Particles and Molecules -in Brute Bodies.</span></h4> - -<p>It is not only in celestial spaces that we must -search for that mobility of brute matter which imitates -the mobility of living matter. In order to find it we -have only to look about us, or to inquire from -physicists and chemists.</p> - -<p>As far as geologists are concerned, M. le Dantec -tells us somewhere of one who divided minerals into -<i>living rocks</i>—rocks capable of change of structure, of -evolution under the influence of atmospheric causes; -and <i>dead rocks</i>—rocks which, like clay, have found at -the end of all their changes a final state of repose. -Jerome Cardan, a celebrated scientist of the sixteenth -century, at once mathematician, naturalist, and -physician, declared not only that stones live, but -that they suffer from disease, grow old, and die. -The jewellers of the present day use similar language -of certain precious stones; the torquoise, for example.</p> - -<p>The alchemists carried these ideas to an extreme. -It is not necessary here to recall the past, to evoke -the hermetic beliefs and the dreams of the alchemists, -who held that the different kinds of matter lived, -developed, and were transmuted into each other.</p> - -<p><span class="pagenum" id="Page_262">[Pg 262]</span></p> - -<p>I refer to precise and recent data, established by -the most expert investigators, and related by one of -them, Charles Edward Guillaume, some years ago, -before the <i>Société helvétique des Sciences naturelles</i>. -These data show that determinate forms of matter -may live and die, in the sense that they may be -slowly and continuously modified, always in the same -direction, until they have attained an ultimate and -definitive state of eternal repose.</p> - -<p><i>The Internal Movements of Bodies.</i>—Swift’s reply to -an idle fellow who spoke slightingly of work is well -known. “In England,” said the author of <i>Gulliver’s -Travels</i>, “men work, women work, horses work, -oxen work, water works, fire works, and beer works; -it is only the pig who does nothing at all; he must, -therefore, be the only gentleman in England.” We -know very well that English gentlemen also work. -Indeed, everybody and everything works. And the -great wit was nearer right than he supposed in comparing -men and things in this respect. Everything -is at work; everything in nature strives and toils, at -every stage, in every degree. Immobility and repose -in the case of natural things are usually deceptive; -the seeming quietude of matter is caused by our -inability to appreciate its internal movements. Because -of their minuteness we do not perceive the -swarming particles that compose it, and which, under -the impassible surface of the bodies, oscillate, displace -each other, move to and fro, and group themselves -into forms and positions adapted to the conditions -of the environment. In comparison with these -microscopic elements we are like Swift’s giant among -the Lilliputians; and this is far from being a sufficiently -forcible comparison.</p> - -<p><span class="pagenum" id="Page_263">[Pg 263]</span></p> - -<p><i>Kinetic Conception of Molecular Motion.</i>—The idea -of this peculiar form of motion is by no means new to -us. We were familiarized with it in scientific theories -during our school days. The atomic theory teaches -us that matter behaves, from a chemical point of -view, as if it were divided into molecules and atoms. -The kinetic theory explains the constitution of gases -and the effects of heat by supposing that these -particles are endowed with movements of rotation -and displacement. The wave theory explains photic -phenomena by supposing peculiar vibratory movements -in a special medium—the ether. But these -are merely hypotheses which are not at all necessary; -they are the images of things, not the things themselves.</p> - -<p><i>Reality of the Motion of Particles.</i>—Here there is -no question of hypotheses. This internal agitation, -this interior labour, this incessant activity of matter -are positive facts, an objective reality. It is true that -when the chemical or mechanical equilibrium of -bodies is disturbed it is only restored more or less -slowly. Sometimes days and years are required -before it is regained. Scarcely do they attain this -relative repose when they are again disturbed, for the -environment itself is not fixed; it experiences variations -which react in their turn upon the body under -consideration; and it is only at the end of these -variations, at the end of their respective periods, that -they will attain together, in a universal uniformity, an -eternal repose.</p> - -<p>We shall see that metallic alloys undergo continual -physical and chemical changes. They are -always seeking a more or less elusive equilibrium. -Physicists in modern times have given their attention<span class="pagenum" id="Page_264">[Pg 264]</span> -to this internal activity of material bodies, to the -pursuit of stability. Wiedemann, Warburg, Tomlinson, -MM. Duguet, Brillouin, Duhem, and Bouasse -have revived the old experimental researches of -Coulomb and Wertheim on the elasticity of bodies, -the effects of pressures and thrusts, the hammering, -tempering, and annealing of metals.</p> - -<p>The internal activity manifested under these circumstances -presents quite remarkable characteristics -which cannot but be compared to the analogous -phenomena presented by living bodies. Thus have -arisen even in physics, a figurative terminology, and -metaphorical expressions borrowed from biology.</p> - -<p><i>Comparison of the Activity of Particles with Vital -Activity.</i>—Since Lord Kelvin first spoke of the <i>fatigue</i> -of metals, or the <i>fatigue</i> of elasticity, Bose has -shown in these same bodies the fatigue of electrical -contact. The term <i>accommodation</i> has been employed -in the study of torsion, and according to Tomlinson -for the very phenomena which are the inverse of -those of fatigue. The phenomena presented by glass -when acted on by an external force which slowly -bends it, have been called facts of adaptation. The -manner in which a bar of steel resists wire-drawing -has been compared to <i>defensive</i> processes against -threatened rupture. And M. C. E. Guillaume speaks -somewhere of “the heroic resistance of the bar of -nickel-steel.” The term “defence” has also been -applied to the behaviour of chloride or iodide of -silver when exposed to light.</p> - -<p>There has been no hesitation in using the term -“memory” concurrently with that of hysteresis to -designate the behaviour of bodies acted on by -magnetism or by certain mechanical forces. It is<span class="pagenum" id="Page_265">[Pg 265]</span> -true that M. H. Bouasse protests in the name of the -physico-mathematicians against the employment of -these figurative expressions. But has he not himself -written “a twisted wire is a wound-up watch,” and -elsewhere, “the properties of bodies depend at every -moment upon all anterior modifications”? Does not -this imply that they retain in some manner the -impression of their past evolution? Powerful deformative -agencies leave a trace of their action; they -modify the body’s condition of molecular aggregation, -and some physicists go so far as to say that they even -modify its chemical constitution. With the exception -of M. Duhem, the disciples of the mechanical school -who have studied elasticity admit that the effect of an -external force upon a body depends upon the forces -which have been previously acting on it, and not -merely upon those which are acting on it at the -present moment. Its present state cannot be anticipated, -it is the recapitulation of preceding states. -The effect of a torsional force upon a new wire will -be different from that of the same force upon a wire -previously subjected to torsions and detorsions. It -was with reference to actions of this kind that -Boltzmann, in 1876, declared that “a wire that has -been twisted or drawn out remembers for a certain -time the deformations which it has undergone.” -This memory is obliterated and disappears after a -certain definite period. Here then, in a problem of -static equilibrium, we find introduced an unexpected -factor—time.</p> - -<p>To sum up, it is the physicists themselves who -have indicated the correspondence between the condition -of existence in many brute bodies and that in -many living bodies. It cannot be expected that<span class="pagenum" id="Page_266">[Pg 266]</span> -these analogies will in any way serve as explanations. -We should rather seek to derive the vital from the -physical phenomenon. This is the sole ambition of -the physiologist. To derive the physical from the -vital phenomenon would be unreasonable. We do -not attempt to do this here. It is nevertheless true -that analogies are of service, were it only to shake the -support which, from the time of Aristotle, has been -accorded to the division of the bodies of nature into -<i>psuchia</i> and <i>apsuchia</i>—<i>i.e.</i>, into living and brute -bodies.</p> - - -<h4>§ 2. <span class="smcap">The Brownian Movement</span>.</h4> - -<p><i>The Existence of the Brownian Movement.</i>—The -simplest way of judging of the working activity of -matter is to observe it when the liberty of the -particles is not interfered with by the action of the -neighbouring particles. We approximate to this -condition when we watch, through the microscope, -grains of dust suspended in a liquid, or globules of -oil suspended in water. Now what we see is well -known to all microscopists. If the granulations are -sufficiently small, they seem to be never at rest. -They are animated by a kind of incessant tremor; -we see the phenomena called the “Brownian movement.” -This movement has struck all observers since -the invention of the magnifying glass or simple -microscope. But the English botanist, Brown, in -1827, made it the object of special research and gave -it his name. The exact explanation of it remained -for a long time obscure. It was given in 1894 by -M. Gouy, the learned physicist of the Faculty of -Lyons.</p> - -<p><span class="pagenum" id="Page_267">[Pg 267]</span></p> - -<p>The observer who for the first time looks through -the microscope at a drop of water from the river, from -the sea, or from any ordinary source—that is to say, -water not specially purified—is struck with surprise -and admiration at the motion revealed to him. -Infusoria, microscopic articulata, and various micro-organisms -people the microscopic field, and animate -it by their movements; but at the same time all sorts -of particles are also agitated, particles which cannot -be considered as living beings, and which are, in fact, -nothing but organic detritus, mineral dust, and debris -of every description. Very often the singular movements -of these granulations, which simulate up to a -certain point those of living beings, have perplexed -the observer or led him to erroneous conclusions, and -the bodies have been taken for animalcules or for -bacteria.</p> - -<p><i>Characters of this Movement.</i>—But it is as a rule -quite easy to avoid this confusion. The Brownian -movement is a kind of oscillation, a stationary, -dancing to-and-fro movement. It is a Saint Vitus’s -dance on one and the same spot, and is thus distinguished -from the movements of displacement -customary with animate beings. Each particle has -its own special dance. Each one acts on its own -account, independently of its neighbour. There is, -however, in the execution of these individual oscillations -a kind of common and regular character which -arises from the fact that their amplitudes differ -little from each other. The largest particles are -the slowest; when above four thousandths of a -millimetre in diameter, they almost cease to be -mobile. The smallest are the most active. When so -small as to be barely visible in the microscope, the<span class="pagenum" id="Page_268">[Pg 268]</span> -movement is extremely rapid, and can only occasionally -be perceived. It is probable that it would be -still more accelerated in smaller objects; but the latter -will always escape our observation.</p> - -<p><i>Its Independence of the Nature of the Bodies and of the -Environment.</i>—M. Gouy remarked that the movement -depends neither on the nature nor on the form -of the particles. Even the nature of the liquid has -but little effect. Its degree of viscosity alone comes -into play. The movements are, indeed, more lively -in alcohol or ether, which are very mobile liquids; -they are slow in sulphuric acid and in glycerine. In -water, a grain one two-thousandth of a millimetre in -diameter traverses, in a second, ten or twelve times its -own length.</p> - -<p>The fact that the Brownian movement is seen in -liquors which have been boiled, in acids and in -concentrated alkalies, in toxic solutions of all degrees -of temperature, shows conclusively that the phenomenon -has no vital significance; that it is in no way -connected with vital activity so called.</p> - -<p><i>Its Indefinite Duration.</i>—The most remarkable character -of this phenomenon is its permanence, its -indefinite duration. The movement never ceases, -the particles never attain repose and equilibrium. -Granitic rocks contain quartz crystals which, at the -moment of their formation, include within a closed -cavity a drop of water containing a bubble of gas. -These bubbles, contemporary with the Plutonian age -of the globe, have never since their formation ceased -to manifest the Brownian movement.</p> - -<p><i>Its Independence of External Conditions.</i>—What is -the cause of this eternal oscillation? Is it a tremor -of the earth? No! M. Gouy saw the Brownian<span class="pagenum" id="Page_269">[Pg 269]</span> -movement far away from cities, where the mercurial -mirror of a seismoscope showed no subterranean -vibration. It does not increase when the vibrations -occur and become quite appreciable. Neither is it -changed by variation in light, magnetism, or electric -influences; in a word, by any external occurrences. -The result of observation is to place before us the -paradox of a phenomenon which is kept up and -indefinitely perpetuated in the interior of a body -without known external cause.</p> - -<p><i>The Brownian Movement must be the First Stage of -Molecular Motion.</i>—When we take in our hands a -sheet of quartz containing a gaseous inclusion, we -seem to be holding a perfectly inert object. When -we have placed it upon the stage of the microscope, -and have seen the agitation of the bubble, we are -convinced that this seeming inertia is merely an -illusion.</p> - -<p>Repose exists only because of our limited vision. -We see the objects as we see from afar a crowd of -people. We perceive them only as a whole, without -being able to discern the individuals or their movements. -A visible object is, in the same way, a mass -of particles. It is a molecular crowd. It gives us -the impression of an indivisible mass, of a block in -repose.</p> - -<p>But as soon as the lens brings us near to this -crowd, as soon as the microscope enlarges for us the -minute elements of the brute body, then they appear -to us, and we perceive the continual agitation of those -elements which are less than four thousandths of a -millimetre in diameter. The smaller the particles -under consideration, the more lively are their movements. -From this we infer that if we could perceive<span class="pagenum" id="Page_270">[Pg 270]</span> -molecules, whose probable dimensions are about one -thousand times less, their probable velocity would be, -as required by the kinetic theory, some hundreds of -metres per second. In the case of objects we can -only just see, the Brownian velocity is only a few -thousandths of a millimetre per second. No doubt, -concludes M. Gouy, the particles that show this -velocity are really enormous when compared with -true molecules. From this point of view the -Brownian movement is but the first degree, and a -magnified picture of the molecular vibrations assumed -in the kinetic theory.</p> - - -<h4>§ 3. <span class="smcap">The Internal Activity of Bodies.</span></h4> - -<p><i>Migration of Material Particles.</i>—In the Brownian -movement we take into account only very small, -isolated masses, small free fragments—<i>i.e.</i>, material -particles which are not hampered by their relations to -neighbouring particles. Any one but a physicist -might believe that in true solids endowed with -cohesion and tenacity, in which the molecules were -bound one to the other, in which form and volume -are fixed, there could be no longer movements or -changes. This is a mistake. Physics teaches us the -contrary, and, in late years especially, has furnished -us characteristic examples. There are real migrations -of material particles throughout solid bodies—migrations -of considerable extent. They are accomplished -through the agency of diverse forces acting externally—pressures, -thrusts, torsions; sometimes under the -action of light, sometimes under the action of electricity, -sometimes under the influence of forces of<span class="pagenum" id="Page_271">[Pg 271]</span> -diffusion. The microscopic observation of alloys by -H. and A. Lechatelier, J. Hopkinson, Osmond, Charpy, -J. R. Benoit; researches into their physical and -chemical properties by Calvert, Matthiessen, Riche, -Roberts Austen, Lodge, Laurie, and C. E. Guillaume; -experiments on the electrolysis of glass, and the -curious results of Bose upon electrical contact of -metals, show in a striking manner the chemical and -kinetic evolutions which occur in the interior of -bodies.</p> - -<p><i>Migration under the Action of Weight.</i>—An experiment -by Obermeyer, dating from 1877, furnishes -a good example of the motions of solid bodies -through a hardened viscid mass, taking place under -the influence of weight. The black wax that -shoemakers and boatbuilders use, is a kind of resin -extracted from the pine and other resinous trees, -melted in water, and separated from the more fluid -part which rises from it. Its colour is due to the -lampblack produced by the combustion of straw and -fragments of bark. At an ordinary temperature it is -a mass so hard that it cannot always be easily -scratched by the finger-nail; but if it is left to itself -in a receptacle, it finally yields, spreads out as if it -were a liquid, and conforms to the shape of the vessel. -Suppose we place within a cavity hollowed out of a -piece of wood a portion of this substance, and keep it -there by means of a few pebbles, having previously -placed at the bottom of the cavity a few fragments of -some light substance, such as cork. The piece of wax -is thus between a light body below and a heavy body -above. If we wait a few days, this order is reversed—the -wax has filled the cavity by conforming to it; -the cork has passed through the wax and appears on<span class="pagenum" id="Page_272">[Pg 272]</span> -the surface, while the stones are at the bottom. We -have here the celebrated experiment of the flask with -the three elements, in which are seen the liquids -mercury, oil, and water superposed in the order of -their density, but in this case demonstrated with -solid bodies.</p> - -<p><i>Influence of Diffusion.</i>—Diffusion, which disseminates -liquids throughout each other, may also cause -solids to pass through other solids. Of this W. -Roberts Austen gave a convincing proof. This ingenious -physicist placed a little cylinder of lead upon -a disc of gold, and kept the whole at the temperature -of boiling water. At this temperature both metals -are perfectly solid, for the melting point of gold is -1,200° C., and of lead is 330°. Still, after this contact -has been prolonged for a month and a half, analysis -shows that the gold has become diffused through the -top of the cylinder of lead.</p> - -<p><i>Influence of Electrolysis.</i>—Electrolysis offers another -no less remarkable means of transportation. By its -means we may force metals, such as sodium or lithium, -through glass walls. The experiment may be performed -as indicated by M. Charles Guillaume. A -glass bulb containing mercury is placed in a bath of -sodium amalgam, and a current is then made to pass -from within outward. After some time it can be -shown that the metal has penetrated the wall of the -bulb, and has become dissolved within it.</p> - -<p><i>Influence of Mechanical Pressure.</i>—Mechanical pressure -is also capable of causing one metal to pass into -another. We need not recall the well-known experiment -of Cailletet, who, by employing considerable -pressure, caused mercury to sweat through a block of -iron. In a more simple manner W. Spring showed<span class="pagenum" id="Page_273">[Pg 273]</span> -that a disc of copper could be welded to a disc of tin -by pressing them strongly one against the other. Up -to a certain distance from the surfaces of contact -a real alloy is formed; a layer of bronze of a certain -thickness unites the two metals, and this could not -take place did not the particles of both metals -mutually interpenetrate.</p> - - -<h4>§ 4. <span class="smcap">Internal Activity of Alloys.</span></h4> - -<p><i>Structure of Alloys.</i>—Metallic alloys have a remarkable -structure, which is essentially mobile, and -which we have only now begun to understand by the -aid of the microscope. Microscopical examination -justifies to a certain degree Coulomb’s conjecture. -That illustrious physicist explained the physical properties -of metals by imagining them to be formed of -two kinds of elements—integral particles, to which the -metal owes its elastic properties, and a <i>cement</i> which -binds the particles, and to which it owes its coherence. -M. Brillouin has also taken up this hypothesis of -duality of structure. The metal is supposed to be -formed of very small, isolated, crystalline grains, -embedded in an almost continuous network of viscous -matter. A more or less compact mass surrounding -more or less distinct crystals is the conception which -may be formed of an alloy.</p> - -<p><i>Changes of Structure produced by Deforming -Agencies.</i>—It has been shown that profound changes -of crystalline structure can be produced by various -mechanical means, such as hammering, and the -stretching of metallic bars carried to the point of -rupture. Some of these changes are very slow, and -it is only after months and years that they are com<span class="pagenum" id="Page_274">[Pg 274]</span>pleted, -and the metal attains the definite equilibrium -corresponding to the conditions to which it is exposed. -Though there may be discussions concerning the -extent of the transformations to which it is subjected, -though some believe they affect the chemical condition -of the alloy, while others limit its power to -physical effects, it is nevertheless true—and this -brings us back to our subject—that the mass of these -metals is at work, and that it only slowly attains the -phase of complete repose.</p> - -<p><i>The Slow Re-establishment of Equilibrium. Residual -Effect.</i>—These operations by which the physical -characters of metals are changed, and by which they -are adapted to a variety of industrial needs—compression, -hammering, rolling, stretching, and torsion—have -an immediate, very apparent effect; but they -have also a consecutive effect, slowly produced, much -less marked and less evident. This is the “residual -effect,” or “Nachwirkung” of the Germans. It is not -without importance, even in practical applications.</p> - -<p>Heat also creates a kind of <i>forced equilibrium</i>. -This becomes but slowly modified, so that a body -may remain for a long time in a state which is, however, -not the most stable for the conditions under -which it is considered. The number of these bodies -<i>not in equilibrium</i> is as great as that of the substances -which have been exposed to fusion. All the Plutonic -rocks are in this condition. Glass presents a condition -of the same kind. Thermometers placed in -melting ice do not always mark the zero Centigrade. -This displacement of the zero point falsifies all -records if care is not taken to correct it. The -correction usually requires prolonged observation. -The theory of the displacement of the thermometric<span class="pagenum" id="Page_275">[Pg 275]</span> -zero is not entirely established; but we may suppose, -with the author of the <i>Traité de Thermométrie</i>, that in -glass, as in alloys, are to be found compounds which -vary according to the temperature. At each temperature -glass tends to assume a determinate composition -and a corresponding state of equilibrium; -but the previous temperature to which it has been -subjected clearly has an influence on the rapidity -with which it attains its state of repose. The effect -of variation is more marked when we observe glass of -more complicated composition. We can understand -that those which contain comparable quantities of the -two alkalies, soda and potash, may be more subject -to these modifications than those having a more -simple composition based on a single alkali.</p> - -<p><i>Effects of Annealing.</i>—A piece of brass wire that -has been drawn and then heated is the scene of -certain very remarkable internal changes, and these -have been only recently recognized. The violent -treatment of the metallic thread in forcing it through -the hole in the die has crushed the crystalline -particles; the interior state of the wire is that of -broken crystals embedded in a granular mass. -Heating changes all that. The crystals separate, -repair themselves, and are built up again; they are -then hard, geometrical bodies, in an amorphous, -relatively soft and plastic mass; their number keeps -on increasing; equilibrium is not established until the -entire mass is crystallized. We may imagine how -many displacements, enormous when compared with -their dimensions, the molecules have to undergo when -passing through the resisting mass, and arranging -themselves in definite places in the crystalline -structures.</p> - -<p><span class="pagenum" id="Page_276">[Pg 276]</span></p> - -<p>In the same way, too, in the manufacture of steel, -the particles of coal at first applied to the surface -pass through the iron.</p> - -<p>This <i>faculty of molecular displacement</i> enables the -metal in some cases to modify its state at one point -or another. The use made of this faculty under -certain circumstances is very curious, greatly resembling -the adaptation of an animal to its environment, -or the methods of defence against agents that -might destroy it.</p> - -<p><i>Effect of Stretching. Hartmann’s Experiment.</i>—When -a cylindrical rod of metal, held firmly at either -end—a test-piece, as it is called in metallurgy—is -pulled sufficiently hard, it often elongates considerably, -part of the elongation disappearing as soon as -the strain ceases, and the other part remaining. The -total elongation is thus the sum of an “elastic -elongation,” which is temporary, and a “permanent -elongation.” If we continue the stretching, there -appears at some point of the rod a local extension -with contraction of sectional area. It is here that the -rod will break.</p> - -<p>But in place of continuing the stretching, Mr. -Hartmann suspends it. He stops, as if to give the -“metal-being” time to rally. During this delay it -would seem that the molecules hasten to the menaced -point to reinforce and harden the weak part. In -fact the metal, which was soft at other points, at -this spot looks like tempered metal. It is no longer -extensible.</p> - -<p>When the experimenter begins the stretching again -after this rest, and after the narrowed bar has been -rolled and become cylindrical again, the local extension -and sectional contraction is forced to occur at<span class="pagenum" id="Page_277">[Pg 277]</span> -another point. If another rest is given at this point -the metal will also become hardened.</p> - -<p>If we repeat the experiment a sufficient number of -times, we shall find a total transformation of the rod, -which becomes hardened throughout its entire extent. -It will break rather than elongate if the stretching is -sufficiently severe.</p> - -<p><i>Nickel Steels—their “Heroic” Resistance.</i>—Nickel -steels present this phenomena in an exaggerated -degree. The alternation of operations which we -have just described, bringing the various parts of an -ordinary steel rod into a tempered state, is not -necessary with nickel steel. The effect is produced -in the course of a single trial. As soon as there is -any tendency to contraction the alloy hardens at that -precise place; the contraction is hardly noticeable; -the movement is stopped at this point to attack -another weak point, stops there again and attacks a -third, and so on; and, finally, the paradoxical fact -appears that a rod of metal which was in a soft state -and could be considerably elongated has now become -throughout its whole extent as hard, brittle, and -inextensible as tempered steel. It is in connection -with this point that M. C. E. Guillaume spoke of -“heroic resistance to rupture.” It would seem, in -fact, as if the ferro-nickel bar had reinforced each -weak point as it was threatened. It is only at the -end of these efforts that the inevitable catastrophe -occurs.</p> - -<p><i>Effect of Temperature.</i>—When the temperature -changes, it is seen that these ferro-nickel bars elongate -or retract, modifying at the same time their chemical -constitution. But these effects, like those which occur -in the glass bulb of a thermometer, do not occur<span class="pagenum" id="Page_278">[Pg 278]</span> -at once. They are produced rapidly for one part, and -more slowly for a small remaining portion. Bars of -ferro-nickel which have been kept at the same -temperature change gradually in length in the course -of a year. Can we find a better proof of internal -activity occurring in a substance differing so greatly -from living matter?</p> - -<p><i>Nature of the Activity of Particles.</i>—These are -examples of the internal activity that occurs in brute -bodies. Besides, these facts that we are quoting -merely to refute Bichat’s assertion relative to the -immutability of brute bodies, and to show us their -activity, also afford us another proof. They show -that this activity, like that of animals, wards off -foreign intervention, and that this parrying of the -attack, again like that of animals, is adapted for the -defence and preservation of the brute mass. So that -if we consider of special importance the adaptative, -teleological characteristic of vital phenomena, a -characteristic which is so easily made too much of -in biological interpretations, we may also find it -again in the inanimate world. To this end we may -add to the preceding examples one more which is -no less remarkable. This is the famous case of -Becquerel’s process for colour-photography.</p> - -<p><i>Colour-Photography.</i>—A greyish plate, treated with -chloride or iodide of silver and exposed to a red light, -rapidly becomes red. It is then exposed to green -light, and after passing through dull and obscure -tints it becomes green. To explain this remarkable -phenomenon, we cannot improve on the following -statement:—The silver salt protects itself against -the light that threatens its existence; that light -causes it to pass through all kinds of stages of<span class="pagenum" id="Page_279">[Pg 279]</span> -coloration before reducing it; the salt stops at the -stage which protects it best. It stops at red, if it is -red light that assails it, because in becoming red by -reflection it best repels that light—<i>i.e.</i>, it absorbs it -the least.</p> - -<p>It may then be advantageous, for the comprehension -of natural phenomena, to regard the transformation -of inanimate matter as manifestations of a -kind of internal life.</p> - -<p><i>Conclusion. Relations of the Surrounding Medium -to the Living Being and the Brute Body.</i>—Brute -bodies, then, are not immutable any more than are -living bodies. Both depend on the medium that -surrounds them, and they depend upon it in the -same way. Life brings together, brings into conflict, -an appropriate organism and a suitable environment. -Auguste Comte and Claude Bernard have taught -us that vital phenomena result from the reciprocal -action of these two factors which are in close correlation. -It is also from the reciprocal action of the -environment and the brute body that inevitably -result the phenomena which that body presents. -The living body is sometimes more sensitive to -variations of the ambient medium than is the brute -body, but at other times the reverse is the case. -For example, there is no living organism as impressionable -to any kind of stimulus whatever as the -bolometer is to the slightest variations of temperature.</p> - -<p>There can only be, then, one chemically immutable -body—namely, the atom of a simple body, since, by -its very definition, it remains unaltered and intangible -in combinations. This notion of an unalterable atom -has, however, itself been attacked by the doctrine of -the ionization of particles due to Sir J. J. Thomson;<span class="pagenum" id="Page_280">[Pg 280]</span> -and besides, with very few exceptions—those of -cadmium, mercury, and the gases of the argon series—the -atoms of simple bodies cannot exist in a free -state.</p> - -<p>Thus, as in the vital struggle, the ambient medium -by means of alimentation furnishes to the living being, -whether whole or fragmentary, the materials of its -organization and the energies which it brings into play. -It also furnishes to brute bodies their materials and -their energies.</p> - -<p>It is also said that the ambient medium furnishes -to the living being a third class of things, the -<i>stimuli</i> of its activities—<i>i.e.</i>, its “provocation to action.” -The protozoon finds in the aquatic environment -which is its habitat the stimuli which provoke it to -move and to absorb its food. The cells of the -metazoon encounter in the same way in the lymph, -the blood, and the interstitial liquids which bathe -them, the shock, the stimulus which brings their -energies into play. They do not derive from themselves, -by a mysterious spontaneity without parallel -in the rest of nature, the capricious principle which -sets them in motion.</p> - -<p>Vital spontaneity, so readily accepted by persons -ignorant of biology, is disproved by the whole history -of the science. Every vital manifestation is a response -to a stimulus, a provoked phenomenon. It is unnecessary -to say this is also the case with brute -bodies, since that is precisely the foundation of the -great principle of the inertia of matter. It is plain -that it is also as applicable to living as to inanimate -matter.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_281">[Pg 281]</span></p> - -<h3 class="nobreak" id="CHAPTER_V_4">CHAPTER V.<br /> - - -<small><span class="smcap">Specific Form. Living Bodies and Crystals.</span></small></h3> -</div> - -<p class="prel">§ 1. Specific form and chemical constitution—The wide distribution -of crystalline forms—Organization of crystals—Law -of relation between specific form and chemical -constitution—Value of form as a characteristic of brute -and living beings—Parentage, living beings and mineral -parentage—Iso-morphism and the faculty of cross-breeding—Other -analogies. § 2. Acquisition and re-establishment -of the specific form—Mutilation and regeneration of crystals—Mechanism -of reparation.</p> - - - -<p>§ 1. <i>Specific Form and Chemical Constitution.</i>—In -the enumeration which we have made of the essential -features of vitality there are three that are, so to -speak, of the highest value. They are, in the order of -their importance:—The possession of a specific form; -the faculty of growth or nutrition; and finally, the -faculty of reproduction by generation. By restricting -our comparison between brute bodies and living -bodies to these truly fundamental characters we -sensibly restrict the field, but we shall see that it -does not disappear.</p> - -<p><i>Wide Distribution of Crystalline Forms.</i>—The -consideration of specific forms shows us that in -the mineral world we need only consider crystallized -bodies, as they are almost the only ones that possess -definite form. In restricting ourselves to this category -we do not limit our field as much as might be sup<span class="pagenum" id="Page_282">[Pg 282]</span>posed. -Crystalline forms are very widely distributed. -They are, in a measure, universal. Matter has a -decided tendency to assume these forms whenever the -physical forces which it obeys act with order and -regularity, and when their action is undisturbed by -accidental occurrences. In the same way, too, living -forms are only possible in regulated environments, -under normal conditions, protected from cataclysms -and convulsions of nature.</p> - -<p>The possession of a specific form is the most -significant feature of an organized being. Its -tendency, from the time it begins to develop from -the germ, is toward the acquirement of that form. -The progressive manner in which it seeks to realize -its architectural plan in spite of the obstacles and -difficulties that arise—healing its wounds, repairing -its mutilations—all this, in the eyes of the philosophical -biologist, forms what is perhaps the most -striking characteristic of a living being, that which -best shows its unity and its individuality. This -property of organogenesis seems pre-eminently the -vital property. It is not so, however, for crystalline -bodies possess it in an almost equal degree.</p> - -<p>The parallel between the crystal and a living being -has been often drawn. I will not reproduce it here -in detail. My sole desire, after sketching its principal -features, is to call attention to the new information -that has been brought out by recent investigations.</p> - -<p><i>Organization of Crystals. Views of Haüy, Delafosse, -Bravais, and of Wallerant.</i>—In botany, zoology, -and crystallography we understand by form an -assemblage of material constituents co-ordinated in -a definite system—<i>i.e.</i>, the organization itself. The -body of man, for example, is an edifice in which sixty<span class="pagenum" id="Page_283">[Pg 283]</span> -trillion cells ought each to find its own predetermined -place.</p> - -<p>In crystallography also we understand by form the -organization which crystals present. The grouping -of the elements of crystals is, perhaps, more simple. -They are none the less organized, in the same sense -that living bodies are.</p> - -<p>Their organization, while more uniform than that -of living bodies, still shows a considerable amount of -variation. It should not be assumed that the area of -a crystal is completely filled, with contiguous parts -applied one to the other by plane faces, as might be -supposed from the phenomenon of cleavage which -dissociates the parts of the crystalline body into -solids of this kind. In reality, the constituent parts -are separated from each other by spaces. They are -arranged in a quincunx, as Haüy put it, or along the -lines of a network, to use the terms of Delafosse and -Bravais. The intervals left between them are incomparably -larger than their diameters. So that in the -organization of a crystal it is necessary to take into -account two quite different things:—An element, the -crystalline particle, which is a certain aggregate of -chemical molecules having a determinate geometrical -form; and a more or less regular, parallelopipedic network, -along the edges of which are arranged in a constant -and definite manner the aforesaid particles. The -external form of the crystal indicates the existence -of the network. Its optical properties depend upon -the action of the particles, as Wallerant has shown: -Thus we must distinguish in a crystal between two -kinds of geometrical figures—that of the network -and that of the particle—and their characters of -symmetry may be either concordant or discordant.</p> - -<p><span class="pagenum" id="Page_284">[Pg 284]</span></p> - -<p>The crystalline particle, the element of the crystal, -is therefore a certain molecular complex that repeats -itself identically and is identically placed at the -nodes of the parallelopipedic network. It has been -given different names well calculated to produce -confusion-the crystallographic molecule of Mallard, -the complex particle of other authors. Some have -separated this element into subordinate elements -(the fundamental particles of Wallerant and of -Lapparent).</p> - -<p>These very general outlines will suffice to show -how complex and adjustable is the organization of -the crystalline individual, which in spite of its -geometric regularity and its rigidity, may be compared -with the still more flexible organization of the -living element. The mineral individual is more -stable, more labile—<i>i.e.</i>, less prone to undergo change -than is the living individual. We may say with -M. Lapparent that “crystallized matter presents the -most perfect and stable orderly arrangement of -which the particles of bodies are susceptible.”</p> - -<p><i>Law of Relation of Specific Form to Chemical -Constitution.</i>—Crystallization is a method of acquiring -specific form. The geometrical architecture of the -mineral individual is but little less wonderful or -characteristic than that of the living individual. Its -form is the result of the mutual reactions of its -substances and of the medium in which it is produced; -it is the condition of material equilibrium -corresponding to a given situation. This idea of a -specific form belonging to a given substance under -given conditions must be borne in mind. We may -consider it as a kind of principle of nature, an -elementary law, which may serve as a point of<span class="pagenum" id="Page_285">[Pg 285]</span> -departure for the explanation of phenomena. A -particular substance under identical conditions of -environment, must always assume a certain form.</p> - -<p>This close linking of substance and form, admitted -as a postulate in physical sciences, has been carried -into biology by some philosophical naturalists, by -M. Le Dantec, for instance.</p> - -<p>Let us imitate them for a moment. Let us cease -to seek in the living being for the prototype of the -crystal; let us, on the contrary, seek in the crystal the -prototype of the living being. If we succeed in this, -we shall then have found the physical basis of life.</p> - -<p>Let us say, then, with the biologists we have -mentioned, that the substance of each living being is -peculiar to it; that it is specific, and that its form—that -is to say its organization—follows from it. The -morpholpgy of any being whatever, of an animal—of -a setter, for example—or even of a determinate -being—of Peter, of Paul—is the “crystalline form of -their living matter.” It is the only form of equilibrium -that can be assumed under the given conditions -by the substance of the setter, of Peter, or of Paul, -just as the cube is the crystalline form of sea-salt. -In this manner these biologists have supposed that -they could carry back the problem of living form -to the problem of living substance, and at the same -time reduce the biological mystery to the physical -mystery. I have shown above (Chap. V. pp. 199-204) -how far this idea is legitimate, and how far and with -what restrictions it may be welcomed and adopted.</p> - -<p><i>Value of Form as a Characteristic of Living and -Brute Beings.</i>—However this may be, we may say, -without fear of exaggeration, that the crystalline form -characterizes the mineral with no less precision than<span class="pagenum" id="Page_286">[Pg 286]</span> -the anatomical form characterizes the animal and the -plant. In both cases, form—regarded as a method -of distribution of the parts—indicates the individual -and allows us to diagnose it with more or less facility.</p> - -<p><i>Parentage of Living Beings and Mineral Parentage.</i>—Still -another analogy has been noted. In -animals and plants similarity in form indicates -similarity in descent, community of origin, and -proximity in any scheme of classification. In the -same way identity of crystalline form indicates -mineral relationship. Substances chemically analogous -show identical, geometrically superposable -forms, and are thus arranged in family or generic -groups recognizable at a glance.</p> - -<p><i>Isomorphism and the Faculty of Cross-breeding.</i>—And -further, the possibility in the case of isomorphous -bodies, of their replacing each other in the same crystal -during the process of formation and of thus mingling, -so to speak, their congenital elements, may be -compared with the possibility of inter-breeding with -living beings of the same species. Isomorphism is -thus a kind of faculty of crossing. And as the -impossibility of crossing is the touchstone of taxonomic -relationship, testing it, and separating stocks -that ought to be separated, so the operation of -crystallization is also a means of separating from an -accidental mixture of mineral species the pure forms -which are blended therein. Crystallization is the -touchstone of the specific purity of minerals; it is the -great process in chemical purification.</p> - -<p><i>Other Analogies.</i>—The analogies between crystalline -and living forms have been pushed still further -even to the verge of exaggeration.</p> - -<p>The internal and external symmetry of animals<span class="pagenum" id="Page_287">[Pg 287]</span> -and plants has been compared to that of crystals. -Transitions or intergradations have been sought -between the rigid and faceted architecture of the -latter and the flexible structure and curved surface of -the former; the utricular form of flowers of sulphur -on the one hand, and the geometrical structure of the -shells of radiolarians on the other, have shown an -exchange of typical forms between the two systems. -An effort has even been made to draw a parallel -between six of the principal types of the animal -kingdom and the six crystalline systems. If carried -as far as this, our thesis becomes puerile. Real -analogies will suffice. Among these the curious facts -of crystalline renewal come first.</p> - - -<h4>§ 2. <span class="smcap">Cicatrization in Living Beings and in -Crystals.</span></h4> - -<p>We know that living beings not only possess a -typical architecture which they have themselves -constructed, but that they defend it against destructive -agencies, and that if need arise they repair -it. The living organism cicatrizes its wounds, repairs -losses of substance, regenerates more or less perfectly -the parts that have been removed; in other terms, -when it has been mutilated it tends to reconstruct -itself according to the laws of its own morphology. -This phenomenon of reconstitution or reintegration, -these more or less successful efforts to re-establish its -form and its integrity, at first appear to be a characteristic -feature of living beings. This is not the -case.</p> - -<p><i>Mutilation and Re-integration of Crystals.</i>—Crystals—let -us say crystalline individuals—show a<span class="pagenum" id="Page_288">[Pg 288]</span> -similar aptitude for repairing their mutilations. -Pasteur, in an early work, discussed these curious -facts. Other experimenters, Gernez a little later and -Rauber more recently, took up the same subject, but -could do no more than extend and confirm his -observations. Crystals are formed from a primitive -nucleus, as the animal is formed from an egg; their -integral particles are disposed according to efficient -geometrical laws, so as to produce the typical form -by a constructive process that may be compared to -the embryogenic process which builds up the body of -an animal. Now this operation may be disturbed by -accidents in the surrounding medium or by the -deliberate intervention of the experimenter. The -crystal is then mutilated. Pasteur saw that these -mutilations repaired themselves. “When,” said he, -“a crystal from which a piece has been broken off is -replaced in the mother liquor, we see that while it -increases in every direction by a deposit of crystalline -particles, activity occurs at the place where it was -broken off or deformed; and in a few hours this -suffices not only to build up the regular amount -required for the increase of all parts of the crystal, -but to re-establish regularity of form in the mutilated -part.” In other words, the work of formation of the -crystal is carried on much more actively at the point -of lesion than it would have been had there been no -lesion. The same thing would have occurred with a -living being.</p> - -<p><i>Mechanism of Reparation.</i>—Gernez some years later -made known the mechanism of this reparation, or, at -least, its immediate cause. He showed that on the -injured surface the crystal becomes less soluble than -on the other facets. This is not, however, an ex<span class="pagenum" id="Page_289">[Pg 289]</span>ceptional -phenomenon. It is, on the contrary, quite -frequently observed that the different faces of a -crystal show marked differences in solubility. This -is what happens in every case for the mutilated face -in comparison with the others; the matter is less -soluble there. The consequence of this is clear; the -growth must preponderate on that face, since there -the mother liquor will become super-saturated before -being super-saturated for the others. We may -explain this result in another way. Each face of the -crystal in contact with the mother liquor is exposed -to two antagonistic actions: The matter deposited -upon a surface may be taken away and redissolved if, -for any reason whatever, such matter becomes more -soluble than that of the liquid stratum in contact -with it; in the second place, the matter of this liquid -stratum may, under contrary conditions, be deposited, -and thus increase the body of the crystal. There is, -then, for each point of the crystalline facet, a positive -operation of deposit which results in a gain, and a -negative operation of redissolution which results in a -loss. One or the other effect predominates according -as the relative solubility is greater or less for the -matter of the facet under consideration. On the -mutilated surface it is diminished, deposition then -prevails.</p> - -<p>But this is only the immediate cause of the -phenomenon; and if we wish to know why the -solubility has diminished on the mutilated surface -Ostwald explains it to us by showing that crystallization -tends to form a polyhedron in which the -surface energy is a relative minimum.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_290">[Pg 290]</span></p> - -<h3 class="nobreak" id="CHAPTER_VI_4">CHAPTER VI.<br /> - -<small>NUTRITION IN THE LIVING BEING AND IN THE -CRYSTAL.</small></h3></div> - - -<p class="prel">Assimilation and growth in the crystal.—Methods of growth -in the crystal and in the living being; intussusception; -apposition.—Secondary and unimportant character of the -process of intussusception.</p> - - -<p>I have already stated (Chap. VI. p. 209) that nutrition -may be considered as the most characteristic and -essential property of living beings. Such beings are -in a state of continual exchange with the surrounding -medium. They assimilate and dissimilate. By assimilation -the substance of their being increases at -the expense of the surrounding alimentary material, -which is rendered similar to that of the being itself.</p> - -<p><i>Assimilation and Growth in the Crystal.</i>—There -exists in the crystal a property analogous to nutrition, -a kind of nutrility, which is the rudiment of this -fundamental property of living beings. The development -of a crystal starts from a primitive nucleus, the -germ of the crystalline individual that we will -presently compare to the ovum or embryo of a plant -or an animal. Placed in a suitable culture-medium—<i>i.e.</i>, -in a solution of the substance—this germ -develops. It assimilates the matter in solution, -incorporates the particles of it, and increases, preserving -at the same time its form, reproducing its<span class="pagenum" id="Page_291">[Pg 291]</span> -specific type or a variety of it. Its growth proceeds -without interruption. The crystalline individual may -attain quite a large size if we know how to nourish it -properly—we might say, to fatten it. Very frequently, -at a given time, a new particle of the crystal -serves in its turn as a primitive nucleus, and becomes -the point of departure for a new crystal engrafted -upon the first.</p> - -<p>Taken from its mother liquor, placed where it -cannot be nourished, the crystal, arrested in its -growth, falls into a condition of rest not without -analogy to that of a seed or of a reviviscent animal. -Its evolution is resumed with the return of favourable -conditions—the bath of soluble matter.</p> - -<p>The crystal is in a relation of continual exchange -with the surrounding medium which feeds it. These -exchanges are regulated by the state of this medium, -or, more exactly, by the state of the liquid stratum -which is in immediate contact with the crystals. It -loses or it gains in substance if, for example, this -layer becomes heated or cooled more rapidly than the -crystal. In a general way, it assimilates or dissimilates -according as its immediate environment is saturated -or diluted. Here, then, we have a kind of mobile -equilibrium, comparable, in some measure, to that of -the living being.</p> - -<p><i>Methods of Growth of the Crystal and of the Living -Being. Intussusception. Apposition.</i>—In truth, there -seems to be a complete opposition between the crystal -and the living being as regards their manner of -nutrition and growth. In the one case the method is -intussusception; in the other it is apposition. The -crystalline individual is all surface. Its mass is impenetrable -to the nutritive materials. Since only the<span class="pagenum" id="Page_292">[Pg 292]</span> -surface is accessible, the incorporation of similar -particles is possible only by external juxtaposition, -and the edifice increases only because a new layer of -stones has been added to those which were there -before. On the contrary, the body of an animal is a -mass essentially penetrable. The cellular elements -that compose it have more or less rounded and -flexible forms. Their contact is by no means perfect. -They have neither the stiffness nor the precision -of adjustment that the crystalline particles have. -Liquids and gases can insinuate themselves from -without and circulate within the meshes of this loose -construction. Assimilation can therefore take place -throughout its whole depth, and the edifice increases -because each stone is itself increasing.</p> - -<p><i>The Secondary and Commonplace Character of the -Process of Intussusception.</i>—The apparent opposition -of these two processes is doubtless diminished if we -compare the simple mineral individual with the -elementary living unit, the crystalline particle with -the protoplasmic mass of a cell. Without carrying -analysis so far as this, it is yet easy to see that apposition -and intussusception are mechanical means -that living beings employ at one and the same time -and combine according to their necessities. The hard -parts of the internal and external skeleton increase -both by interposition and superposition, at once. It -is by the last method that bones increase in diameter, -and the shells of molluscs, the scales of reptiles and -fishes, and the testae of many radiate animals are -formed. In these organs, as in crystals, life and -nutrition occur at the surface.</p> - -<p>Apposition and intussusception are then secondary, -mechanical arrangements having relation to the<span class="pagenum" id="Page_293">[Pg 293]</span> -physical characters of the body—solidity in the -crystal, semi-fluidity in the cellular protoplasm. If -we compare the inorganic liquid matter with the -semi-fluid organized matter, we recognize that the -addition of substance takes place in the same manner -in each—<i>i.e.</i>, by interposition. If we add a soluble -salt to a fluid, the molecules of the salt separate -themselves and interpose themselves between those -of the fluid. There is, therefore, nothing especially -mysterious or particularly vital about the process of -intussusception. Applied to fluid protoplasm, it is -merely the diffusion that ordinarily occurs in mixed -liquids.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_294">[Pg 294]</span></p> - -<h3 class="nobreak" id="CHAPTER_VII_4">CHAPTER VII.<br /> - -<small>GENERATION IN BRUTE BODIES AND LIVING -BODIES. SPONTANEOUS GENERATION.</small></h3></div> - - -<p class="prel">Protoplasm a substance which continues—Case of the crystal—Characteristics -of generation in the living being—Property -of growth—Supposed to be confined to the living being—Fertilization -of micro-organisms—Fertilization of crystals—Sterilization -of crystalline and living media—Spontaneous -generation of crystals—Metastable and labile zones—Glycerine -crystals—Possible extinction of a crystalline -species—Conclusion.</p> - - -<p>We have not yet exhausted the analogies between a -crystal and the living being. The possession of a -specific form, the tendency to re-establish it by redisintegration -and the existence of a kind of nutrition -are not sufficient to constitute complete similarity. -It still lacks a fundamental character, that of generation. -Chauffard some time ago, in an attack which -he made upon the physiological ideas of his day, -aptly exhibited this weak point. “Let us disregard,” -he said, “those interesting facts relative to the acquisition -of a typical form—facts that are common to the -mineral world as well as to living beings. It is none -the less true that the crystalline type is in no way -derived from other pre-existing types, and that -nothing in crystallization recalls the actions of -ascendants and the laws of heredity.”</p> - -<p>This gap has since been filled. The work of<span class="pagenum" id="Page_295">[Pg 295]</span> -Gernez, of Violette, of Lecoq de Boisbaudran, the experiments -of Ostwald and of Tammann, the observations -of Crookes and of Armstrong—all this series of -researches, so lucidly summarized by M. Leo Errera -in his essays in botanical philosophy, had for their -result the establishment of an unsuspected relation -between the processes of crystallization and those of -generation in animals and plants.</p> - -<p><i>Protoplasm is a Substance which Continues. The -Case of the Crystal.</i>—Under present conditions a living -being of any kind springs from another living being -similar to itself.</p> - -<p>Its protoplasm is always a continuation of the -protoplasm of an ancestor. It is an atavic substance -of which we do not see the beginning; we only see it -continue. The anatomical element comes from a -preceding anatomical element, and the higher animal -itself comes from a pre-existing cell of the material -organism, the ovum. The ladder of filiation reaches -back indefinitely into the past.</p> - -<p>We shall see that there is something analogous to -this in certain crystals. They are born of a preceding -individual; they may be considered as the posterity -of the antecedent crystal. If we speak of the matter -of a crystal as the matter of a living being is spoken -of, in cases of this kind we would say that the -crystalline substance is an atavic substance of which -we see only the continuation, as in the case of -protoplasm.</p> - -<p><i>Characters of Generation in the Living Being.</i>—Growth -of the living substance, and consequently of -the being itself, is the fundamental law of vitality. -Generation is the necessary consequence of growth -(p. 210).</p> - -<p><span class="pagenum" id="Page_296">[Pg 296]</span></p> - -<p>Living elements or cells cannot subsist indefinitely -without increasing and multiplying. The time must -come when the cell divides, either directly or indirectly; -and then, instead of one cell, there are two. -This is the method of generation for the anatomical -element. In a complex individual it is a more or less -restricted part of the organism, usually a simple -sexual cell, that takes on the formation of the new -being, and assures the perpetuity of the protoplasm, -and therefore of the species.</p> - -<p><i>Property of Growth. Its Supposed Restriction to -Living Beings.</i>—At first it would appear that nothing -like this occurs in inanimate nature. The physical -machine, if we furnish it matter and energy, could go -on working indefinitely, without being compelled to -increase and reproduce. Here, then, there is an -entirely new condition peculiar to the organized -being, a property well adapted, it would seem—and -this time without any possible doubt—for separating -living matter from brute matter. It is not so.</p> - -<p>It would not be impossible to imagine a system -of chemical bodies organized like the animal or -vegetable economy, so that a destruction would be -compensated for by a growth. The only thing impossible -is to suppose, with M. le Dantec, a destruction -that would at the same time be an analysis. And an -additional perplexity occurs when he supposes that -in the successive acts exchanges of material may -occur.</p> - -<p>There is no necessity for making this impossible -chemistry a characteristic of the living being. The -chemistry of the living being is general chemistry. -Lavoisier and Berthelot enforced this view. We -should not lose sight of the teachings of the masters.</p> - -<p><span class="pagenum" id="Page_297">[Pg 297]</span></p> - -<p>Let us return to generation, properly so called, and -find in it the characteristics of brute bodies and of -crystals.</p> - -<p><i>The Sowing of Micro-organisms.</i>—When a microbiologist -wishes to propagate a species of micro-organisms, -he places in a culture medium a few -individuals (one is all that is actually necessary), and -soon observes their rapid multiplication. Usually, if -only the ordinary microbes in atmospheric dust are -wanted, the operator need not trouble to charge the -culture; if the culture tube remains open and the -medium is suitably chosen, some germ of a common -species will fall in and the liquid will become -colonized. This has the appearance of spontaneous -generation.</p> - -<p><i>The Sowing of Crystals.</i>—Concentrated solutions of -various substances, supersaturated solutions of sodium -magnesium sulphate, and sodium chlorate are also -wonderful culture media for certain mineral organic -units—certain crystalline germs. Ch. Dufour, experimenting -with water cooled below 0° C., its point -of solidification; Ostwald, with salol kept below 39°.5, -its point of fusion; Tammann, with betol, which -melts at 96°; and, before them, Gernez, with melted -phosphorus and sulphur—all these physicists have -shown that liquids in superfusion are also media -specially appropriate for the culture and propagation -of certain kinds of crystalline individuals.</p> - -<p>Some of these facts have become classic. Lowitz -showed in 1785 that a solution of sodium sulphate -could be concentrated by evaporation so as to contain -more salt than was conformable with the temperature, -without, however, depositing the excess. But if a -solid fragment, a crystal of salt, is thrown into the<span class="pagenum" id="Page_298">[Pg 298]</span> -liquor, the whole of the excess immediately passes -into the state of a crystallized mass. The first -crystal has engendered a second similar to itself; -the latter has engendered a third, and so on from one -to the other. If we compare this phenomenon with -that of the rapid multiplication of a species of -microbes in a suitable culture medium, no difference -will be perceived. Or perhaps we may note one -unimportant difference—the rapidity of the propagation -of the crystalline germs as opposed to the relative -slowness of the generation of the micro-organisms.</p> - -<p>Again, the propagation of crystallization in a supersaturated -or superfused liquid may be delayed by -appropriate devices. The crystalline individual gives -birth, then, to another individual that conforms to its -own type, or even to varieties of that type when such -exist. Into the right branch of a U tube filled with -sulphur in a state of superfusion Gernez dropped -octahedric crystals of sulphur, and into the left branch -prismatic crystals. On either side were produced -new crystals conforming to the type that had been -sown.</p> - -<p><i>Sterilization of Crystalline Media and Living Media.</i>—Ostwald -varied these experiments by using salol. -He melted the substance by heating it above 39∙5°C.; -then, protecting it from crystals of any kind, he let -the solution stand in a closed tube. The salol remained -liquid indefinitely—until it was touched with -a platinum wire that had been in contact with solid -salol—<i>i.e.</i>, until a crystalline germ was introduced. -But if the platinum wire has been previously sterilized -by passing it, as the bacteriologists do, through a -flame, it can then be introduced into the liquor with -impunity.</p> - -<p><span class="pagenum" id="Page_299">[Pg 299]</span></p> - -<p><i>The Dimensions of Crystalline Germs Comparable -to those of Microbes.</i>—We may dilute the solid -salol with inert powder—lactin, for example—dilute -the first mixture with a second, the second with a -third, and so on; then, throwing into the solution of -surfused salol a tenth of a milligram from one of -these various mixtures, we find that the production of -crystals will not take place if the fragment thrown in -weighs less than a millionth of a milligram, or -measures less than ten thousandths of a millimetre -in length. It would seem, then, that these are the -dimensions of the crystalline particle or crystallographic -molecule of salol. In the same way Ostwald -satisfied himself that the crystalline germ of hyposulphite -of soda weighs about a thousand-millionth of -a milligram, and measures a thousandth of a millimetre; -that of chlorate of soda weighs a ten-millionth -of a milligram. These dimensions are entirely comparable -with those of microbes.</p> - -<p>All these phenomena have been studied with a -detail into which it is impossible to enter here, and -which clearly shows more and more intimate analogies -between the formation of crystals and the generation -of micro-organisms.</p> - -<p><i>Extension and Propagation of Crystallization. -Optimum Temperature of Incubation.</i>—Crystallization -which has commenced around a germ is propagated -more or less rapidly, and ends by invading the whole -of the liquor.</p> - -<p>The rapidity of this movement of extension depends -upon the conditions of the medium, especially upon -its temperature. This is shown very well by -Tammann’s experiments with betol. This body, -the salicylic ester of naphthol, fuses at 96° C. If it<span class="pagenum" id="Page_300">[Pg 300]</span> -is melted in tubes sealed at a temperature of 100° C., -it may be cooled to lower and lower temperatures—to -+ 70°, to + 25°, to + 10°, to-5° without solidifying. -Let us suppose that by some combination of circumstances -a few centres of crystallization—that is to -say, of crystalline germs—have appeared in the -solution. Solidification will extend slowly at the -ordinary temperature, at 20° to 25° and thereabouts. -On the other hand, it will be propagated with great -rapidity if the liquor is kept at about 70°. This -point—70°—is the thermal optimum for the propagation -of germs. It is the most favourable -temperature for what may be called their incubation. -As soon as the germs find themselves in a liquor at -70° they increase, multiply, and show that they are in -the best conditions for growth.</p> - -<p><i>Spontaneous Generation of Crystals. Optimum -Temperature for the Appearance of Germs.</i>—If we -consider various supersaturated solutions or liquids -in superfusion, we shall soon discover that they can -be arranged in two categories. Some remain indefinitely -liquid under given conditions unless a -crystalline germ is introduced into them. Others -solidify spontaneously without artificial intervention, -and such crystallization may even be propagated very -rapidly under determinate conditions. This implies -that these are conditions favouring the spontaneous -appearance of germs.</p> - -<p>This distinction between substances of crystalline -generation by filiation and substances of spontaneous -crystalline generation is not specific. The same -substance may present the two methods of generation -according to the conditions in which it is placed. -Betol furnishes a good example of this. Liquefy it at<span class="pagenum" id="Page_301">[Pg 301]</span> -100° in a sealed tube and keep it by means of a stove -above 30°, and it will remain liquid almost indefinitely. -On the other hand, lower its temperature and leave it -for one or two minutes at 10°, and germs will appear -in the liquor; prolong the exposure to this degree of -heat and the number of these spontaneously appearing -germs, appearing in isolation, will rapidly increase. -On the other hand, you will observe that propagation -by filiation—that is to say, by extension from one -to another—is almost absent. The temperature of -10° is not favourable to that method of generation; -and we have just seen, in fact, that it is at a temperature -of about 70° that extension of crystallization -from one to another is best accomplished. The -temperature of 70° was the optimum for propagation -by filiation. Inversely, the temperature of 10° is the -optimum for spontaneous generation. Above and -below this optimum the action is slower. We may -count the centres of crystallization, which slowly -extend further and further, as in a microbic -culture one counts the colonies corresponding to -the germs primitively formed. To sum up, if -there is an optimum for the formation of -crystals, there is a different optimum for their rapid -extension.</p> - -<p><i>The Metastable and Labile Zones.</i>—This phenomena -is general. There is for each substance a set of -conditions (temperature, degree of concentration, -volume of the solution) in which the crystalline -individuals can be produced only by germs or by -filiation. This is what occurs for betol above the -temperature of 30°. The body is then in what -Ostwald has called a <i>metastable</i> zone. There is, -however, for the same body another set of circum<span class="pagenum" id="Page_302">[Pg 302]</span>stances -more or less complete, in which its gems -appear simultaneously. This is what happens for -betol at about the temperature of 10°. These circumstances -are those of the <i>labile zone</i> or zone of -spontaneous generation.</p> - -<p><i>Crystals of Glycerine.</i>—We may go a step further. -Let us suppose, with L. Errera, that we have a liquid -in a state of metastable equilibrium, whose labile -equilibrium is as yet unknown. This is what actually -occurs for a very widely known body, glycerine. -We do not know under what conditions glycerine -crystallizes spontaneously. If we cool it, it becomes -viscous; we cannot obtain its crystals in that way. -It was not found in crystals until 1867. In that -year, in a cask sent from Vienna to London during -winter, crystallised glycerine was found, and Crookes -showed these crystals to the Chemical Society of -London. What circumstances had determined their -formation? We knew not then, and we know not -now. It may be observed that this case of spontaneous -generation of the crystals of glycerine has -not remained the solitary instance. M. Henninger -has noted the accidental formation of glycerine -crystals in a manufactory in St. Denis.</p> - -<p>It may be remarked that this crystalline species -appeared, as living species may have done, at a given -moment in an environment in which a favourable -chance combined the necessary conditions for its -production. It is also quite comparable to the -creation of a living species; for having once appeared -we have been able to perpetuate it. The crystalline -individuals of 1867 have had a posterity. They -have been sown in glycerine in a state of superfusion, -and there they reproduced themselves. These<span class="pagenum" id="Page_303">[Pg 303]</span> -generations have been sufficiently numerous to -spread the species throughout a great part of -Europe. M. Hoogewerf showed a great flask full -to the Dutch biologists who met at Utrecht in -1891. M. L. Errera presented others in June 1899, -to the Society of Medical and Natural Sciences at -Brussels. To-day the great manufactory of Sarg & -Co., of Vienna, is engaged in their production on a -large scale for industrial purposes.</p> - -<p>Thus we are able to study this crystalline species -of glycerine and to determine with precision the -conditions of its continued existence. It has been -shown that it does not resist a temperature of 18°, so -that if precautions were not taken to preserve it, -a single summer would suffice to annihilate all the -crystalline individuals existing on the surface of the -globe, and thus the species would be extinguished.</p> - -<p><i>Possible Extinction of a Crystalline Species.</i>—As -these crystals melt at 18°, this temperature represents -the point of fusion of solid glycerine or the point of -solidification of liquid glycerine. But the liquor -does not solidify at all if its temperature falls below -18° C., as we well know, for it is at that temperature -we use it. Nor does it solidify at zero, nor even at -18° below zero; at 20°, for instance, it merely thickens -and becomes pasty. We only know glycerine, then, in -a state of superfusion, a fact which chemists have not -learned without amazement. Under these conditions, -so analogous to the appearance of a living species, to -its unlimited propagation and to its extinction, the -mineral world offers a quite faithful counterpart to -the animal world. The living body illustrates here -the history of the brute body and facilitates its -exposition. Inversely, the brute body in its turn<span class="pagenum" id="Page_304">[Pg 304]</span> -throws remarkable light on the subject of the living -body, and on one of the most serious problems -relative to its origin, that of spontaneous generation.</p> - -<p><i>Conclusion.</i>—These facts lead to one conclusion. -Until the concourse of propitious circumstances -favourable to their spontaneous generation was -brought about, crystals were obtained only by -filiation. Until the discovery of electro-magnetism, -magnets were made only by filiation, by means of -the simple or double application of a pre-existing -magnet. Before the discovery which fable attributes -to Prometheus, every new fire was produced only by -means of a spark from a pre-existing fire. We are -at the same historical stage as regards the living -world, and that is why, up to the present, there has -never been formed a single particle of living matter -except by filiation, except by the intervention of a -pre-existing living organism.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_305">[Pg 305]</span></p> - -<h2 class="nobreak" id="BOOK_V">BOOK V.<br /> - - -<small>SENESCENCE AND DEATH.</small></h2></div> - - -<p class="prel">Chap. I. The different points of view from which death may be -regarded.—Chap. II. Constitution of the organisms—Partial -death—Collective death.—Chap. III. Physical -and chemical characteristics of cellular death—Necrobiosis.— -Chap. IV. Apparent perennity of complex individuals.—Chap. V. -Immortality of the protozoa and of slightly -differentiated cells.</p> - - - -<p>We grow old and we die. We see the beings -which surround us grow old and disappear. At first -we see no exceptions to this inexorable law, and we -consider it as a universal and inevitable law of -nature. But is this generalization well founded? -Is it true that no being can escape the cruel fate of -old age and death, to which we and all the representatives -of the higher animality are exposed? Or, -on the other hand, are any beings immortal? Biology -answers that, in fact, some beings are immortal. -There are beings to whose life no law assigns a -limit, and they are the simplest, the least differentiated -and the least perfect. Death thus appears to be a -singular privilege attached to organic superiority, the -ransom paid for a masterly complexity. Above these -elementary, monocellular, undifferentiated beings, -which are protected from mortality, we find others, -higher in their organization, which are exposed to<span class="pagenum" id="Page_306">[Pg 306]</span> -it, but with whom death seems but an accident, -avoidable in principle if not in fact. The anatomical -elements of this higher animal are a case in point. -Flourens once tried to persuade us that the threshold -of old age might be made to recede considerably, and -there are biologists in the present day who give us -some glimpse of a kind of vague immortality. We -may, therefore, ask our readers to follow us in our -examination of these re-opened if not novel questions, -and we shall explain the views of contemporary -physiology as to the nature of death, its causes, its -mechanisms, and its signs.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_307">[Pg 307]</span></p> - -<h3 class="nobreak" id="CHAPTER_I_5">CHAPTER I.<br /> - -<small>VARIOUS WAYS OF REGARDING DEATH.</small></h3></div> - - -<p class="prel">Different meanings of the word death—Physiological distinction -between elementary and general death—Non-scientific -opinions—The ordinary point of view—Medical point of -view.—The signs of death are prognostic signs.</p> - - -<p><i>Different Meanings of the Word Death.</i>—An English -philosopher has asserted that the word we translate -by “cause” has no less than sixty-four different meanings -in Plato and forty-eight in Aristotle. The word -“death” has not so many meanings in modern -languages, but still it has many. Sometimes it -indicates an action which is taking place, the action -of dying, and sometimes a state, the state which -succeeds the action of dying. The phenomena it -connotes are in the eyes of many biologists quite -different, according as we watch them in an animal -of complex organization, or on the other hand, in -monocellular beings, protozoa and protophytes.</p> - -<p><i>Physiological Distinction between Elementary Death -and General Death.</i>—We distinguish the death of the -anatomical elements, <i>elementary death</i>, from the -death of the individual regarded as a whole, <i>general -death</i>. Hence we recognize an <i>apparent death</i>, which -is an incomplete and temporary suspension of the -phenomena of vitality, and a <i>real death</i>, which is a -final and total arrest of these phenomena. When<span class="pagenum" id="Page_308">[Pg 308]</span> -we consider it in its essential nature (assumed, but -not known) we look on it as the <i>contrary of life</i>, as -did the Encyclopædia, Cuvier, and Bichat; or we -regard it with others either as the consequence of -life, or simply as the end of life.</p> - -<p><i>Non-scientific Opinions.</i>—What is death to those -outside the realm of science? First of all we find the -consoling solution given by those who believe death -to be the commencement of another life. We next -find ourselves involved in a confused medley, an -infinite diversity of philosophical doubt and superstition. -“A leap into the unknown,” says one. -“Dreamless and unconscious night,” says another. -And again, “A sleep which knows no waking.” -Or, with Horace, “the eternal exile,” or with -Seneca, annihilation. <i>Post mortem nihil; ipsaque -mors nihil.</i></p> - -<p>The idea which is constantly supervening in the -midst of this conflict of opinion is that of the -<i>breaking up</i> of the elements, the union of which -forms the living being. It has, as we shall see, a -real foundation which may perhaps receive the -support of science. We shall not find that the best -way of defining death is to say that it consists of the -“dissolution of the society formed by the anatomical -elements, or again, in the dissolution of the consciousness -that the individual possesses of himself—<i>i.e.</i>, of -the existence of this society.” It is the rupture of -the social bond. The old idea of dispersion is a -variant of the same notion. But the ancients -evidently could not understand, as we do, the nature -of these elements which are associated to form the -living being, and which are liberated or dispersed -by death. We, as biologists, can see microscopical<span class="pagenum" id="Page_309">[Pg 309]</span> -organic unity with a real objective existence. The -ancients were thinking of spiritual elements, of -principles, of entities. To the Romans, who may be -said to have held that there are three souls, death -was produced by their separation from the body. -The first, the breath, the <i>spiritus</i>, mounting towards -celestial regions (<i>astra petit</i>); the second, the <i>shade</i>, -regaining on the surface of the earth and wandering -around the tombs; the third, the <i>manes</i>, descending -to the lower regions. The belief of the Hindoos was -slightly different. The body returned to the earth, -the breath to the winds, the fire of the glance to the -sun, and the ethereal soul to the world of the pure. -Such were the ideas of mortal dispersion formed by -ancient humanity.</p> - -<p>Modern science takes a more objective point of -view. It asks by what facts, by what observable -events death is indicated. Generally speaking, we -may say that these facts interrupt an interior state -of things which was life and to which they put an -end. Thus death is defined by life. It is the -cessation of the events and of the phenomena which -characterize life. We must, therefore, know what -life is to understand the meaning of death. How -wise was Confucius when he said to his disciple, -Li-Kou:—“If we do not know life, how can we -know death?” According to biology there are two -kinds of death because there are two kinds of life; -elementary life and death correspond just as general -life and death do, and this is where scientific opinion -diverges from commonly received opinion.</p> - -<p>What cares the man who reasons as most human -beings do, about this life of the anatomical elements -of his body, the existence and the silent activity of<span class="pagenum" id="Page_310">[Pg 310]</span> -which are in no way revealed to him. What does -their death matter to him? To him there is but one -poignant question, that of being separated or not -being separated from the society of his fellows. -Death is no longer to feel, no longer to think; it is -the assurance that one will never feel, one will never -think again. Sleep, dreamless sleep, is already in our -eyes a kind of transient death; but, when we fall asleep -we are sure of waking again. There is no awaking -from the sleep of death. But that is not all. Man -knows that death, this dreamless sleep that knows no -waking, will be followed by the dissolution of his -body. And what a dissolution will there be for the -body, the object of his continual care! Remember -the description of Cuvier—the flesh that passes from -green to blue and from blue to black, the part which -flows away in putrid venom, the other part which -evaporates in foul emanations, and finally, the few -ashes that remain, the tiny pinch of minerals, saline -or earthy, which are all that is left of that once -animated masterpiece.</p> - -<p><i>The Popular View.</i>—To the man afraid of death -it seems, in the presence of so great a catastrophe, -that the patient analysis of the physiologist scrupulously -noting the succession of phenomena and explaining -their sequence is uninteresting. He will -only attach the slightest importance to knowing that -vestiges of vitality remain in this or that part of his -body, if they do not re-establish in every part the -<i>status quo ante</i>. He cares not to hear that a certain -time after the formal declaration of his death his -nails and his hair will continue to grow, that his -muscles will still have the useless faculty of contraction, -that every organ, every tissue, every element,<span class="pagenum" id="Page_311">[Pg 311]</span> -will oppose a more or less prolonged resistance to the -invasion of death.</p> - -<p><i>Medical View.</i>—It is, however, these very facts and -details, this why and wherefore, which interest the -physiologist. The state of mind of the doctor in this -respect, again, is different. When, for instance, the -doctor declares that such and such a person is dead, -he is really making not so much a statement of fact -as a prediction. How many elements are still living -and will be capable of new birth in this corpse that -he has before his eyes? That is not what he asks -himself, nor is it what we should ask of him. He -knows, besides, that all these partial survivals will be -extinguished and will never find the conditions -necessary to reviviscence, and that the organization -will never be restored to its primal activity; and this -is what he affirms. The fear of premature burial -which haunts so many imaginations is the fear of an -error in the prediction. It is to avoid this that -practical medicine has devoted so much of its -attention to the discovery of a <i>certain</i>—and early—sign -of death. By this we understand the discovery -of a <i>certain prognostic sign of general death</i>. We -want a prognostic sign enabling us to assert that the -life of the brain is now extinguished and will never -be reanimated. And yet there are in that organism -many elements which are still alive. Many others -even may be born anew if we could give them -suitable conditions which they no longer meet with -in the animal machine now thrown out of gear. -What finer example could we give than the experiment -of Kuliabko, the Russian physiologist, who -kept a man’s heart working and beating for eighteen -hours after the official verification of his death.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_312">[Pg 312]</span></p> - -<h3 class="nobreak" id="CHAPTER_II_5">CHAPTER II.<br /> - -<small>THE PROCESS OF DEATH.</small></h3></div> - - -<p class="prel">Constitution of organisms.—Partial lives.—Collective life.—The -rôle of apparatus.—Death by lesion of the major apparatus.—The -vital tripod.—Solidarity of the anatomical -elements.—Humoral solidarity.—Nervous solidarity.—Independence -and subordination of the anatomical elements.</p> - - -<p><i>Partial Lives.</i> <i>Collective Life.</i>—With the exception -of the physiologist, no one, neither he who is ignorant -nor he who is intellectual, nor even the doctor, -troubles his head about the life or the death of the -element, although this is the basis, the real foundation, -of the activity manifested by the social body -and by its different organs. The life of the individual, -of the animal, depends on these elementary -partial lives just as the existence of the State depends -upon that of its citizens. To the physiologist, the -organism is a federation of cellular elements unified -by close association. Goethe compared them to a -“multitude”; Kant to a “nation”; and others have -likened them to a populous city the anatomical -elements of which are the citizens, and which possesses -an individuality of its own. So that the -activity of the federated organism may be discussed -in each of its parts, and then it is <i>elementary life</i>, or -in its totality, and then it is <i>general life</i>. Paracelsus -and Bordeu had a glimpse of this truth when they -considered a life appropriate to each part (<i>vita propria</i>)<span class="pagenum" id="Page_313">[Pg 313]</span> -and a collective life, the life of the whole (<i>vita -communis</i>). In the same way we must distinguish -the <i>elementary death</i>, which is the cessation of the -vital phenomena in the isolated cell, from the <i>general -death</i>, which is the disappearance of the phenomena -which characterised the collectivity, the totality, the -federation, the nation, the city, the whole in so far as -it is a unit.</p> - -<p>These comparisons enable us to understand how -general life depends on the partial lives of each -anatomical citizen. If all die, the nation, the federation, -the total being clearly ceases to exist. This -city has an enormous population—there are thirty -trillion cellules in the body of man; it is peopled -with absolutely sedentary citizens, each of which has -its fixed place, which it never leaves, and in which it -lives and dies. It must possess a system of more or -less perfect arrangements to secure the material life -of each inhabitant. All have analogous requirements: -they feed very much the same; they breathe -in the same way; each in fact has its profession, -industry, talents, and aptitudes by which it contributes -to social life, and on which, in its turn, it -depends. But the process of alimentation is the -same for all. They must have water, nitrogenous -materials and analogous ternaries; the same mineral -substances, and the same vital gas, oxygen. It is no -less necessary that the wastes and the egesta, very -much alike in every respect, should be carried off and -borne away in discharges arranged so as to free the -whole system from the inconvenience, the unhealthiness, -and the danger of these residues.</p> - -<p><i>Secondary Organization in Organs.</i>—That is why, -as we said above, the secondary organizations of the<span class="pagenum" id="Page_314">[Pg 314]</span> -economy exist:—the digestive apparatus which prepares -the food and enables it to pass into the blood, -into the lymph, and finally into the liquid medium -which bathes each cell and constitutes its real -medium; the respiratory apparatus which imports -the oxygen and exports the gaseous excrement, -carbonic acid; the heart and the circulatory system -which distributes through the system the internal -medium, suitably purified and recuperated. The -organization is dominated by the necessities of -cellular life. This is the law of the city, to which -Claude Bernard has given the name of the <i>law of the -constitution of organisms</i>.</p> - -<p><i>Death by Lesion of the Major Organs. Vital -Tripod.</i>—Thus we understand what life is, and at the -same time what is the death of a complex living -being. The city perishes if its more or less complicated -mechanisms which look after its revictualling -and its discharge are seriously affected at any point. -The different groups may survive for a more or less -lengthy period, but progressively deprived of the -means of food or of discharge, they are finally -involved in the general ruin. If the heart stops, -there is a universal famine; if the lungs are seriously -injured, we are asphyxiated; if the principal organ -of discharge, the kidney, ceases to perform its allotted -task, there is a general poisoning by the used-up and -toxic materials retained in the blood.</p> - -<p>We understand how the integrity of the major -organs,—the heart, the lungs, the kidney,—is indispensable -to the maintenance of existence. We -understand that their lesion, by a series of successive -repercussions, involves universal death. We always -die, said the doctors of old, because of the failure of<span class="pagenum" id="Page_315">[Pg 315]</span> -one of these three organs, the heart, the lungs, or the -brain. Life, they said in their inaccurate language, -depends upon these as upon three supports. Hence -the idea of the <i>vital tripod</i>. But it is not only this -trio of organs which maintain the organism; the -kidney and the liver are no less important. In -different degrees each part exercises its action on the -rest. Life is based in reality on the immense -multitude of living cells associated for the formation -of the body; on the thirty trillion anatomical elements, -each part is more or less necessary to all the -rest, according as the bond of solidarity is drawn more -or less closely in the organism under consideration.</p> - -<p><i>Death and the Brain.</i>—There are indeed more noble -elements charged with higher functions than the rest. -These are the nervous elements. Those of the brain -preside over the higher functions of animality, sensibility, -voluntary movement, and the exercise of the -intellect. The rest of the nervous system forms an -instrument of centralization which establishes the -relations of the parts one with the other and secures -their solidarity. When the brain is stricken and its -functions cease, man has lost the consciousness of his -existence. Life seems to have disappeared. We say -of a man in this plight that he no longer lives, thus -confusing general life with the cerebral life which is -its highest manifestation. But the man or the -animal without a brain lives what may be called a -vegetative life. The human anencephalic foetus lives -for some time, just as the foetus which is properly -formed. Observation always shows that this existence -of the other parts of the body cannot be sustained -indefinitely in the absence of that of the brain. -By a series of impulses due to the solidarity of the<span class="pagenum" id="Page_316">[Pg 316]</span> -grouping of the parts, the injury received by the -brain affects by repercussion the other organs, and -leads in the long run to the arrest of elementary life -in all the anatomical elements. The death of the -whole is then complete.</p> - -<p>Doctors have therefore a two-fold reason for saying -that the brain may cause death. The death of the -brain suppresses the highest manifestation of life, and, -in the second place, by a more or less remote counter -stroke, it suppresses life in all the rest of the system.</p> - -<p><i>Death is a Process.</i>—Besides, the fact is general. -The death of one part always involves the death of -the rest—<i>i.e.</i>, universal death. A living organism -cannot be at the same time alive and a cemetery. The -corpses cannot exist side by side with the living -elements. The dead contaminates the living, or in -some other way involves it in its ruin. Death is -propagated; it is a progressive phenomenon which -begins at one point and gradually is extended to the -whole. It has a beginning and a duration. In other -words, the death of a complex organism is a process. -And further, the end of a simple organism, of a -protozoan, of a cell, is itself a process infinitely -more shortened.</p> - -<p>The very perfection of the organism is therefore the -cause of its fragility. It is the degree of solidarity of -the parts one with another which involves the one set -in the catastrophe of the rest, just as in a delicate -piece of mechanism the derangement of a wheel brings -nearer and nearer the total breakdown. The important -parts, the lungs, the heart, the brain, suffer no -serious alteration without the reflex being felt throughout. -But there are also wheels less evident, the -integrity of which is scarcely less necessary.</p> - -<p><span class="pagenum" id="Page_317">[Pg 317]</span></p> - -<p><i>The Solidarity of the Anatomical Elements.</i>—The -cause of the mortal process—<i>i.e.</i>, of the extension and -the propagation of an initial destruction—is therefore -to be found in the solidarity of the parts of the -organism. The closer it is the greater do the chances -of destruction become, for the accident which has -happened to one will by repercussions affect the -others.</p> - -<p>Now the solidarity of the parts of the organism -may be carried out in two ways; there is a <i>humoral -solidarity</i> and a <i>nervous solidarity</i>.</p> - -<p><i>Humoral Solidarity.</i>—Humoral solidarity is realized -by the mixture of humours. All the liquids of the -organism which have lodged in the interstices of the -elements and which soak the tissues, are in contact -and in relation of exchange one with another, and -through the permeable wall of the small vessels they -are in relation with the blood and the lymph.</p> - -<p>All the liquid atmospheres which surround the -cells and form their ambient medium have intercommunication. -A change having taken place in one -cellular group, and therefore in the corresponding -liquid, modifies the medium of the further or nearer -groups, and therefore these groups themselves.</p> - -<p><i>Nervous Solidarity.</i>—But the real instrument of the -solidarity of the part is the nervous system. Thanks -to it in the living machine the component activities of -the cellular multitude restrain and control one another. -Nervous solidarity makes of the complex being not a -mob of cells, but a connected system, an individual in -which the parts are subordinated to the whole and the -whole to the parts; in which the social organism has -its rights just as the individual has his rights. The -whole secret of the vital functional activity of the<span class="pagenum" id="Page_318">[Pg 318]</span> -complex being is contained in these two factors:—the -independence and the subordination of the elementary -lives. General life is the harmony of the elementary -lives, their symphony.</p> - -<p><i>Independence and Subordination of the Anatomical -Elements.</i>—The independence of the anatomical elements -results from the fact that they are the real -depositaries of the vital properties, the really active -components. On the other hand the subordination of -the parts to the whole is the very condition of the -preservation of form in animals and plants. The -architecture which is characteristic of them, the -morphological plan which they realize in their -evolutive development which they are ever preserving -and repairing, form a striking proof of this. This -dependence in no way contradicts the autonomy of -the elements. For when with Claude Bernard and -Virchow we study the circumstances we see that -the element accommodates itself to the organic -plan without violence to its nature. It behaves -in its natural place as it would behave elsewhere, -if elsewhere it were to meet around it the -same liquid medium which at once is a stimulant -and a food. This at least is the conclusion we -may draw from experiments on transplanting, or -on animal and vegetable grafting. Neither the -neighbouring elements, nor the whole system act on it -at a distance by a kind of mysterious induction, -according to the ideas of the vitalists, in order to -regulate the activity of the element. They contribute -solely to the composition of the liquid atmosphere -which bathes it. They intervene in order to provide -it with a certain environment whose very characteristic -physical and chemical constitution regulates its<span class="pagenum" id="Page_319">[Pg 319]</span> -activity. This constitution may be some day imitated -by the devices of experiment. When that result is -achieved the anatomical element will live in isolation -exactly as it lives in the organic association, and the -mysterious bond which causes its solidarity with the -rest of the economy will become intelligible. In fact, -we may defer more or less the maturity of this -prophecy, but there is no doubt that we are daily -nearing its fulfilment.</p> - -<p>The general life of the complex being is therefore -the more or less perfect synergy, the <i>ordered process</i> of -elementary lives. General death is the destruction of -these partial lives. The nervous system, the instrument -of this harmony of the parts, represents the -social bond. It keeps most of the partial elements -under its sway, and is thus the intermediary of their -relations. The closer this dependence, the higher the -development of the nervous apparatus, and the better, -also, is assured the universal solidarity and therefore -the unity of the organism. Cellular federation -assumes the characteristic of a unique individuality -in proportion to the development of this nervous -centralization. With an ideal perfect nervous system -the correlation of the parts would also attain perfection. -As Cuvier said: “None could experience -change without a change in the rest.”</p> - -<p>But no animal possesses this extreme solidarity of -the parts of the living economy. It is a philosopher’s -dream. It is the dream of Kant, to whom the perfect -organism would be “a teleological system,” a system -of reciprocal ends and means, a sum total of parts -each existing for and by the rest, for and by the -whole. An organism so completely connected would -be unlikely to live. In fact, living organisms show a<span class="pagenum" id="Page_320">[Pg 320]</span> -little more freedom in the interplay of their parts. -Their nervous apparatus fortunately does not attain -this imaginary perfection; their unity is not so -rigorous. The idea of individuality, of individual -existence, is therefore not absolute but relative. -There are all degrees of it according to the development -of the nervous system. What the man in the -street and the doctor himself understand by death is -the situation created by the stopping of the general -wheels, the brain, the heart, and the lungs. If the -breath leaves no trace on the glass held to the mouth, -if the beating of the heart is no longer perceptible by -the hand which touches or the ear which listens, if the -movement and the reaction of sensitiveness have -ceased to be manifest, these signs make us conclude -that it is death. But this conclusion, as we have said -before, is a prognostic rather than a judgment of fact. -It expresses the belief that the subject will certainly -die, and not that it is from this moment dead. To -the physiologist the subject is only on the way to die. -The process has started. The only real death is -when the universal death of all the elements has been -consummated.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_321">[Pg 321]</span></p> - -<h3 class="nobreak" id="CHAPTER_III_5">CHAPTER III.<br /> - -<small>PHYSICAL AND CHEMICAL CHARACTERS OF CELLULAR -DEATH. NECROBIOSIS. GROWING OLD.</small></h3></div> - - -<p class="prel">Characteristic of elementary life—Changes produced by death -in the composition and the death of the cell—Schlemm; -Loew; Bokorny; Pflüger; A. Gautier; Duclaux—The -processive character of death—Accidental death—Necrobiosis—Atrophy—Degeneration—So-called -natural death—Senescence—Metchnikoff’s -theory of senescence—Objections.</p> - - -<p>Elementary death is nothing but the suppression -in the anatomical elements of all the phenomena of -vitality.</p> - -<p><i>Characteristics of Elementary Life.</i>—The characteristic -features of elementary life have been -sufficiently fixed by science. First of all, there is -<i>morphological unity</i>. All the living elements have an -identical morphological composition. That is to say -that life is only accomplished and sustained in all its -fulness in organic units possessing the anatomical -constitution of the cell, with its cytoplasm and its -nucleus, constituted on the classical type. In the -second place, there is <i>chemical unity</i>. The constituent -matter, the matter of which the cell is built up, diverges -but little from a chemical type—a proteid complex, -with a hexonic nucleus, and from a physical model -which is an emulsion of granulous, immiscible liquids, -of different viscosities. The third character consists in<span class="pagenum" id="Page_322">[Pg 322]</span> -the possession of a <i>specific form</i> acquired, preserved, -and repaired by the element. The fourth character, -and perhaps the most essential of all, is <i>the property -of growth</i> or <i>nutrition</i> with its consequence, namely, a -relation of exchanges with the external medium, -exchanges in which oxygen plays considerable part. -Finally, there is a last property, that of <i>reproduction</i>, -which in a certain measure is a necessary consequence -of the preceding,—<i>i.e.</i>, of growth.</p> - -<p>These five vital characters of the elements are most -in evidence in cells living in isolation, in microscopical -beings formed of a single cell, protophytes and -protozoa. But we find them also in the associations -formed by the cells among one another—<i>i.e.</i>, in -ordinary plants and animals, multicellular complexes, -called for this reason metaphytes and metazoa. Free -or associated, the anatomical elements behave in the -same way—feed, grow, breathe, digest in the same -manner. As a matter of fact, the grouping of the -cells, the relations, proximity and contiguity, which -they assume, introduce some variants into the expression -of the common phenomena; but these slight -differences cannot disguise the essential community -of the vital processes.</p> - -<p>The majority of physiologists, following Claude -Bernard, admit as valent and convincing the proof that -the illustrious experimenter furnished of this unity -of the vital processes. There are, however, a few -voices crying in the wilderness. M. Le Dantec is one. -In his new theory of life he amplifies and exalts the -differences which exist between the elementary life of -the proteids and the associated life of the metazoa. -In them he can see nothing but contrasts and -deviations.</p> - -<p><span class="pagenum" id="Page_323">[Pg 323]</span></p> - -<p>If this is elementary life, let us ask what is -<i>elementary death</i>—<i>i.e.</i>, the death of the cell. And in -this connection let us ask the questions which we have -to examine in the case of animals high in organization, -and of man himself. What are the characteristics -of elementary death? When the cell dies, is its death -preceded by a growing old or senescence? What are -the preliminary signs and the acknowledged symptoms?</p> - -<p><i>Changes Produced by Death.</i>—The state of death is -only truly realized when the fundamental properties -of living matter enumerated above have entirely -disappeared. We must follow step by step this disappearance -in all the anatomical elements of the -metazoan.</p> - -<p>Now the properties of the cell are connected with -the physical and chemical organization of living -matter. For them to disappear entirely, this organization -must be destroyed as far as all that is essential -in it is concerned. We cannot admit with the -vitalists that there is any material difference between -the dead and the living, and that only an immaterial -principle which has escaped into the air distinguishes -the corpse from the animated being. In fact, the -external configuration may be almost preserved, and -the corpse may bear the aspect and the forms of the -preceding state. But this appearance is deceptive. -Something in reality has changed. The structure, -the chemical composition of the living substance, -have undergone essential changes. What are these -changes?</p> - -<p><i>Physical Changes.</i>—Certain physiologists have -endeavoured to determine them. Klemm, a botanist, -pointed out in 1895 the physical changes which -characterize the death of vegetable cells—loss of<span class="pagenum" id="Page_324">[Pg 324]</span> -turgescence, fragmentation of the protoplasm, the -formation of granules, and the appearance of vacuoles.</p> - -<p><i>Chemical Changes.</i>—O. Loew and Bokorny laid -great stress in 1886 and 1896 on the chemical changes. -The living protoplasm according to them is an -unstable proteid compound. A slight change would -detach from the albuminoid molecule a nucleus with -the function of aldehyde, and at the same time would -transform an amido-group into an amido-group. This -would suffice for the transition of the protoplasm from -the living to the dead state. This theory is based on -the fact that the compounds which exercise a toxic -action on the living cell, without acting chemically on -the dead albumin, are easily fixed by the aldehydes; -and on the fact that many of them, which attack -simultaneously the living albuminoids and the dead -albumin, easily combine with the amido-group.</p> - -<p>E. Pflüger, a celebrated German scientist, has -considered living matter as an albumin spontaneously -decomposable, the essential nucleus of which is formed -by cyanogen. Its active instability would be due to -the penetration into the molecule of the oxygen which -fixes on the carbon and separates it from the nitrogen. -Armand Gautier has not confirmed this view. -Duclaux (1898) has stated that the difference between -the living and the dead albumin would be of a stereochemical -order.</p> - -<p><i>Progressive Character of Death. Accidental Death.</i>—We -have seen that in general the disappearance of -the characteristics of vitality is not instantaneous, at -least in the natural course of things, in complex organisms. -It is the end of a more or less rapid process. But -death is not instantaneous in the isolated anatomical -element any more than it is in the protozoan or<span class="pagenum" id="Page_325">[Pg 325]</span> -protophyte. We must have recourse to very violent -devices of destruction to kill the cell at a blow, to -leave absolutely nothing of its organization existing. -The protoplasm of yeast when violently crushed by -Büchner still possessed the power of secreting soluble -ferments. A powerful action, a very high temperature, -is necessary to obtain the result. <i>A fortiori</i>, -the difficulty increases in the case of complex organisms, -all of whose living elements cannot be attacked -at the same moment by the destructive cause. A -mechanical action, capable of destroying at one blow -all the living parts of a complex being, of an animal, -of a plant, must be of almost inconceivable power. -The blow of a Nasmyth hammer would not be strong -enough.</p> - -<p>The chemical alteration produced by a very toxic -substance distributed throughout the blood, and thus -brought into contact with each element, would produce -a disorganization which, however rapid it were, could -not be called instantaneous. And the same holds -good of physical agents.</p> - -<p>But these are not the processes of nature under -normal circumstances. They are accidents or devices. -We shall leave on one side their consideration and -we shall only deal here with the natural processes of -the organism.</p> - -<p>Imagine it placed in a medium appropriate to its -needs and following out without intervening complications -the evolution assigned to it by its -constitution. Experiment tells us that this natural -evolution in every case known to us ends in death. -Death supervenes sooner or later. For beings higher -in organization, which we can bring into closer and -closer resemblance to man, we find that they die of<span class="pagenum" id="Page_326">[Pg 326]</span> -disease, by accident, or of old age. And as disease -is an accident, we may naturally ask if what we call -old age is not also a disease.</p> - -<p>However that may be, the mortal process, being -never instantaneous, has a duration, a beginning, a -development, an end—in a word, a history. It -constitutes an intermediary phase between perfect -life and certain death.</p> - -<p><i>Necrobiosis.</i> <i>Atrophy.</i> <i>Degeneration.</i>—The process -according to the circumstances may be shortened or -prolonged. When death is the result of violence -events are precipitated. The physical and chemical -transformations of the living matter constitute a kind -of acute alteration called by Schultze and Virchow -<i>necrobiosis</i>. According to the pathologists, there are -two kinds of <i>necrobiosis</i>:—that by <i>destruction</i>, by -<i>simple atrophy</i>, which causes the anatomical elements -to disappear gradually without undergoing appreciable -modifications; and <i>necrobiosis by degeneration</i>, -which transforms the protoplasm into fatty matter -into calcareous matter, into granulations (fatty degeneration, -calcification, granulous degeneration). -There is no disagreement as to the causes of this -necrobiosis. They are always accidental; they -originate in external circumstances:—the insufficiency -of the alimentary materials, of water, of oxygen; the -presence in the medium of real poisons destroying -the organized matter; the violent intervention of -physical agents, heat, electricity; the reflex on the -composition of the cellular atmosphere of a violent -attack on some essential organ, the heart, the lungs, -the kidneys.</p> - -<p><i>Senescence.</i> <i>Old Age.</i>—In a second category we -must place the mortal processes, slow in their move<span class="pagenum" id="Page_327">[Pg 327]</span>ment, -in which we cannot see the intervention of -clearly accidental and abnormal disturbing agents. -Death appears to be the termination of a breaking-up -proceeding by insensible degrees in consequence of the -progressive accumulation of very small inappreciable -perturbations. This slow breaking up is adequately -expressed by the term—growing old, or senescence. -The alterations by which it is betrayed in the cell are -especially <i>atrophic</i>, but they are also accompanied, -however, by different forms of degeneration. An -extremely important question arises on this subject, -and that is whether the phenomena of senility have -their cause in the cell itself, if they are inevitably -found in its organization, and therefore if old age and -death are natural and necessary phenomena. Or, on -the other hand, should we consider them as due to a -progressive alteration of the medium, the character of -which would be accidental although frequent or -habitual? This, in a word, is the problem which has -so often engaged the attention of philosophical -biologists. Are old age and death natural and -inevitable phenomena?</p> - -<p>The recent experiments of Loeb and Calkins, and -all similar observations, tend to attribute to the -phenomenon of growing old the character of a -remediable accident. But the remedy has not been -found, and the animal finally succumbs to these slow -transformations of its anatomical elements. We then -say that it <i>dies of old age</i>.</p> - -<p><i>Metchnikoff’s Theory of Senescence. Objections.</i>—Metchnikoff -has proposed a theory of the mechanism -of this general senescence. The elements of the -conjunctive tissue, phagocytes, macrophages, which -exist everywhere around the specialized and higher<span class="pagenum" id="Page_328">[Pg 328]</span> -anatomical elements would destroy and devour them -as soon as their vitality diminishes, and would take -their place. In the brain, for example, it would be -the phagocytes which, attacking the nervous cellules, -would disorganize the higher elements, incapable of -defending themselves. This substitution of the conjunctive -tissue, which only possesses vegetative properties -of a low order, for the nervous tissues, which -possesses very high vegetative properties, results in -an evident breaking-up. The gross element of -violent and energetic vitality stifles the refined and -higher element.</p> - -<p>This expulsion is a very real fact. It constitutes -what is called senile sclerosis. But the active <i>rôle</i> -attributed to it by Metchnikoff in the process of -degeneration is not so certain. An expert observer -in the microscopic study of the nervous system, M. -Marinesco, does not accept this interpretation as far -as the senescence of the elements of the brain is concerned. -Diminution of the cell, the decrease in the -number of its stainable granulations, chromatolysis, -the formation of inert, pigmented substances—all -these phenomena which characterize the breaking-up -of the cerebral cells would be accomplished, according -to this observer, without the intervention of the -conjunctive elements, the phagocytes.</p> - -<p>The characteristic of extensive and progressive -process presented by death necessitates in a complex -organism, which is a prey to it, the existence -side by side of living and dead cells. Similarly, in -the organism which is growing old, there are young -elements and elements of every age side by side with -senile elements. As long as the disorganization of -the last has not gone too far, they may be rejuvenated.<span class="pagenum" id="Page_329">[Pg 329]</span> -All we have to do is to restore to them an appropriate -ambient medium. The whole question is one of -knowing and being able to realize, for this or that -part which we wish to reanimate and to rejuvenate, -the very special or very delicate conditions that this -medium must fulfil. As we have said, success is -attained in this respect as far as the heart is concerned, -and this is why we are able to reanimate and -to revive the heart of a dead man. It is hoped that -ideas along these lines will extend with the progress -of physiology.</p> - -<p>After this sketch of the conditions and of the -varieties of cellular death we must return to the -essential problem which is engaging the curiosity of -biologists and philosophers. Is death unavoidable, -inevitable? Is it the necessary consequence of life -itself, the inevitable issue, the inevitable end?</p> - -<p>There are two ways of endeavouring to solve this -question of the inevitability of death. The first is to -examine popular observation, practised, so to speak, -unintelligently and without special precautions. The -second is to analyze everything we know relative to -the conditions of elementary life.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_330">[Pg 330]</span></p> - -<h3 class="nobreak" id="CHAPTER_IV_5">CHAPTER IV.<br /> - -<small>THE APPARENT PERENNITY OF COMPLEX -INDIVIDUALS.</small></h3></div> - - -<p class="prel">Millenary trees—Plants with a definite rhizome—Vegetables -reproduced by cuttings—Animal colonies—Destruction due -to extrinsic causes—Difficulty of interpretation.</p> - - -<p>Popular opinion teaches us that living beings have -only a transient existence, and as a poet has said: -“Life is but a flash between two dark nights.” But, -on the other hand, simple observation shows us, or -appears to show us, beings whose duration of existence -is far longer, and practically illimitable.</p> - -<p><i>Millenary Trees.</i>—We know of trees of venerable -antiquity. Among these patriarchs of the vegetable -world there is a chestnut tree on Mount Etna which -is ten centuries old, and an ivy in Scotland which is -said to be thirty centuries old. Trees of 5000 years -old are not absolutely unknown. We may mention -among those of that age the famous dragon tree<a id="FNanchor_21" href="#Footnote_21" class="fnanchor">[21]</a> at -Orotava, in the island of Teneriffe. Two other -examples are known in California—the pseudo-cedar, -or <i>Tascodium</i>, at Sacramento, and a <i>Sequoïa gigantea</i>. -We know that the olive tree may live 700 years. -There are cedars 800 years old and oaks of the age of -1,500 years.</p> - -<p><i>Plants with a Rhizome.</i>—Vegetable species of<span class="pagenum" id="Page_331">[Pg 331]</span> -almost unlimited duration of life are known to -botanists. Such, for instance, are plants with a -definite rhizome, such as colchicum. Autumnal -colchicum has a subterranean root, the bulb of -which pushes out every year fresh axes for a new -bloom; and as each of these new axes stretches out -an almost constant length, a botanist once set himself -the singular problem of discovering how long it would -take such a foot, if suitably directed, to travel round -the world.</p> - -<p><i>Vegetables Reproduced by Cuttings.</i>—Vegetables reproduced -by slips furnish another example of living -beings of indefinite duration. The weeping willows -which adorn the banks of sheets of water in the parks -and gardens throughout the whole of Europe have -sprung, directly or indirectly, from slips of the first -<i>Salix Babylonica</i> introduced to the West. May it not -be said that they are the permanent fragments of that -one and the same willow?</p> - -<p><i>Animal Colonies.</i>—These examples, as well as those -furnished to zoologists by the consideration of the -polypi which have produced by their slow growth the -reefs, or <i>atolls</i>, of the Polynesian seas, do not, however, -prove the perennity of living beings. The -argument is valueless, for it is founded upon a confusion. -It turns on the difficulty that biologists -experience in defining the individual. The oak and -the polypus are not simple individuals, but associations -of individuals, or, to use Hegel’s expression, -the nations of which we see the successive generations. -We give to this succession of generations a -unique existence, and our reasoning comes to this, -that we confer on each present citizen of this social -body the antiquity which belongs to the whole.</p> - -<p><span class="pagenum" id="Page_332">[Pg 332]</span></p> - -<p><i>Destruction of the Social Individual due to Extrinsic -Causes.</i>—As for the destruction, the death of this -social individual, of this hundred-year-old tree, it -seems indeed that there is no ground for considering -it a natural necessity. We find the sufficient reason -of its usual end in the repercussion on the individual -of external and contingent circumstances. The cause -of the death of a tree, of an oak many centuries old, -is to be found in the ambient conditions, and not in -some internal condition. Cold and heat, damp and -dryness, the weight of the snow, the mechanical -action of the rain, of hail, of winds unchained, of -lightning; the ravages of insects and parasites—these -are what really work its ruin. And further, -the new branches, appearing every year and increasing -the load the trunk has to bear, increase the -pressure of the parts, and make more difficult the -motion of the sap. But for these obstacles, external, -so to speak, to the vegetable being itself, it would -continue indefinitely to bloom, to fructify, and as -each spring returned to show fresh buds.</p> - -<p><i>Difficulty of Interpretation.</i>—In this as in all other -examples we must know the nature of the beings that -we see lasting on and braving the centuries. Is it the -individual? Is it the species? Is it a living being, -properly so called, having its unity and its individuality, -or is it a series of generations succeeding -one another in time and extending in space? In a -word, the question is one of knowing if we have to do -with a real tree or with a genealogical tree. We are -just as uncertain when we deal with animals. What -is the being that lasts on—a series of generations or -an individual? This doubt forbids us to draw any -conclusion from the observation of complex beings.<span class="pagenum" id="Page_333">[Pg 333]</span> -We must therefore return from them to the <i>elementary -being</i>; and we must examine it from the point of view -of perennity or of vital decay. Let us then ask the -questions that we have already examined with reference -to animals high in organization and to man -himself. Is the death of the cell an inevitable characteristic? -Are there any cells, protophytes, protozoa, -which are immortal?</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_334">[Pg 334]</span></p> - -<h3 class="nobreak" id="CHAPTER_V_5">CHAPTER V.<br /> - -<small>THE IMMORTALITY OF THE PROTOZOA.</small></h3></div> - - -<p class="prel">Impossibility of life without evolution—Law of increase and -division—Immortality of the protozoa—Death, a phenomenon -of adaptation which has appeared in the course of -the ages—The infusoria—The death of the infusoria—Two -kinds of reproduction—The caryogamic rejuvenescence of -Maupas—Calkins on rejuvenescence—Causes of senescence—Impossibility -of life without evolution.</p> - - -<p>We take into account, <i>a priori</i>, the conditions that -must be fulfilled by the monocellular being in order -to escape the inevitability of evolution, of the succession -of ages, of old age, and of death. It must be -able indefinitely to maintain itself in a normal régime, -without changing, without increasing, maintaining its -constant morphological and chemical composition, in -an environment vast enough for it to be unaltered by -the borrowings or the spendings resulting from its -nutrition—<i>i.e.</i>, it must remain constant in the presence -of the constant being. We might conceive of a -nutrition perfect enough, of exchanges exact enough, -and regular enough, for the state of things to be -indefinitely maintained. This would be absolute -permanence realized in the vital mobility.</p> - -<p><i>The Law of Growth and Division.</i>—This model of -a perfect and invariable machine does not exist in -nature. Life is incompatible with the absolute per<span class="pagenum" id="Page_335">[Pg 335]</span>manence -of the dimensions and the forms of the living -organism.</p> - -<p>In a word, it is a rigorous law of living nature that -the cell can neither live indefinitely without growth, -nor grow indefinitely without division.</p> - -<p>Why is this so? Why is there this impossibility -of a regular régime in which the cell would be maintained -in magnitude without diminution or increase? -Why has nutrition as a necessary consequence the -growth of the element? This is what we do not -positively know.</p> - -<p>Things are so. It is an irreducible fact, peculiar to -the protoplasm, a characteristic of the living matter -of the cell. It is the fundamental basis of the property -of generation. That is all we can say about it. -Real living beings have therefore inevitably an evolution. -They are not unchangeable. In its simple form -this evolution consists in the fact that the cell grows, -divides, and diminishes by this division, begins the -upward march which ends in a new division. And -so on.</p> - -<p><i>Immortality of the Protozoa.</i>—It may happen, and -it does happen in fact, that this series of acts is -repeated indefinitely at any rate unless an accidental -cause should interrupt it. The animal thus describes -an indefinite curve, constituted by a series of indentations, -the highest point of which corresponds to the -maximum of size, and the lowest point to the -diminution which succeeds the division. This state of -things has no inevitable end if the medium does not -change. The being is immortal.</p> - -<p>In fact, the compound beings of a single cell, protophytes -and protozoa, the algae and the unicellular -mushrooms, at the minimum stage of differentiation,<span class="pagenum" id="Page_336">[Pg 336]</span> -escape the necessity of death. They have not, as -Weismann remarks, the real immortality of the gods -of mythology, who were invulnerable. On the contrary, -they are infinitely vulnerable, fragile, and -perishable; myriads die every moment. But their -death is not inevitable. They succumb to accidents, -never to old age.</p> - -<p>Imagine one of these beings placed in a culture -medium favourable to the full exercise of its activities, -and, moreover, wide enough in its extent to be unaffected -by the infinitely small quantities of material -which the animal may take from it or expel into it. -Suppose, for example, it is an infusorian in an ocean. -In this invariable medium the being lives, increases, -and grows continually. When it has reached the -limits of a size fixed by its specific law, it divides into -two parts, which are indistinguishable the one from -the other. It leaves one of its halves to colonize in its -neighbourhood, and it begins its evolution as before. -There is no reason why the fact should not be repeated -indefinitely, since nothing is changed, either -in the medium or in the animal.</p> - -<p>To sum up. The phenomena which take place in -the cell of the protozoan do not behave as a cause of -check. The medium allows the organism to revictual -and to discharge itself in such a way and with such -perfection that the animal is always living in a regular -régime, and, with the exception of its growth and -later on of its division, there is nothing changed -in it.</p> - -<p><i>Death a Phenomenon of Adaptation—It appeared in -the Course of the Ages.</i>—This immortality belongs in -principle to all the protista which are reproduced by -simple and equal division. If it be remarked that<span class="pagenum" id="Page_337">[Pg 337]</span> -these rudimentary organisms endowed with perennity -are the first living forms which have shown themselves -on the surface of the globe, and that they have -no doubt preceded many others—the multicellular, -for instance, which are liable, on the contrary, to -decay—the conclusion is obvious:—Life has long -existed without death. Death has been a phenomenon -of adaptation which has appeared in the -course of the ages in consequence of the evolution of -species.</p> - -<p><i>The Death of Infusoria.</i>—We may ask ourselves at -what moment in the history of the globe, at what -period of the evolution of its fauna, this novelty, -death, made its appearance. The celebrated experiments -of Maupas on the senescence of the infusoria -seem to authorize us to give a precise answer to this -question. By means of these experiments we are -led to believe that death must have appeared -at the same time as sexual reproduction. Death -became possible when this process of generation -was established, not in all its plenitude, but in its -humblest beginnings, under the rudimentary forms -of unequal division and of conjugation. This -happened when the infusoria began to people the -waters.</p> - -<p><i>The Two Modes of Multiplication.</i>—Infusoria are, in -fact, capable of multiplication by simple division. -It is true to say that in addition to this resource, the -only one which interests us here, because it is the -only one which confers immortality, they possess -another. They present and exercise under certain -circumstances a second mode of reproduction, caryogamic -conjugation. It is a rather complicated -process in its detail, but it is definitively summed up<span class="pagenum" id="Page_338">[Pg 338]</span> -as the temporary pairing of two individuals, which -are otherwise very much alike, and which cannot be -distinguished as male and female. They become -closely united on one of their faces; they reciprocally -exchange a semi-nucleus which passes into the conjoint -individual; and then they separate. But -infusoria can be prevented from this conjunction by -regularly isolating them immediately after their birth. -Then they grow, and are constrained after a lapse of -time to divide according to the first method.</p> - -<p>Maupas has shown that the infusoria could not -accommodate themselves to this régime indefinitely; -they could not go on dividing for ever. After a -certain number of divisions they show signs of -degeneration and of evident decay. The size -diminishes, the nuclear organs become atrophied, -all the activities fail, and the infusorian perishes. -It succumbs to this kind of senile atrophy unless it -is given an opportunity of conjugation with another -infusorian in the same plight. In this act it then -derives new strength, it grows larger, attains its -proper size, and builds up its organs once more. -Conjugation gives it life, youth, and immortality.</p> - -<p><i>Alimentary Rejuvenescence.</i>—Recent observations -due to Mr. G. N. Calkins, an American biologist, -and confirmed by other investigators, have shown -that this method of rejuvenescence is not the only -one, and is not even the most efficacious. Conjugation -has no mysterious, specific virtue. The -infusoria need not be married in order to be -rejuvenated. It is sufficient to improve their food. -In the case of the “tailed” paramecium we may -substitute beef broth and phosphates for conjugation. -Calkins observed 665 consecutive generations<span class="pagenum" id="Page_339">[Pg 339]</span> -without blemish, without exhaustion, and without -any sign of old age. Plenty of food and simple -drugs have successfully resisted senility and the -train of atrophic degenerations which it involves.</p> - -<p><i>Causes of Senescence.</i>—As for the causes of senescence -which have been remedied with such success, -they are not exactly known. Calkins thinks that -senescence results from the progressive losses to the -organism of some substance essential to life. Conjugation -or intensive alimentation would act by building -up again this necessary compound. G. Loisel -believes on the contrary that it is a matter of the -progressive accumulation of toxic products due to a -kind of alimentary auto-intoxication.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_340">[Pg 340]</span></p> - -<h3 class="nobreak" id="CHAPTER_VI_5">CHAPTER VI.<br /> - -<small>LETHALITY OF THE METAZOA AND OF -DIFFERENTIATED CELLS.</small></h3></div> - - -<p class="prel">Evolution and death of metazoa.—Possible rejuvenescence of -the differentiated cells by the conditions of the medium.—Conditions -of the medium for immortal cells.—The -immortal elements of metazoa.—The element in accidental -and remediable death.—Somatic cells and sexual cells.</p> - - -<p><i>Evolution and Death of Metazoa.</i>—We have seen -that the infusoria are no longer animals in which -material exchanges take place with sufficient perfection, -and in which cellular division, the consequence -of growth, is produced with sufficient precision and -equality for life to be carried on indefinitely in -a perfect equilibrium in the appropriate medium -without alteration or check. <i>A fortiori</i> we no -longer find the perfect regularity of nutritive -exchange in the classes above them. In a word, -starting from this inferior group, there are no -animated beings in the state of existence which -Le Dantec calls “condition <span class="allsmcap">Iº</span> of manifested life?” -Living matter, instead of being continually kept -identical in conditions of identical media, is modified -in the course of existence. It becomes dependent on -time. It describes a declining trajectory; it experiences -evolution, decay, and death. Thus the<span class="pagenum" id="Page_341">[Pg 341]</span> -fundamental condition of invariable youth and -of immortality fails in all metazoa. The vital -wastes accumulate in all through the insufficiency -or the imperfection of nutritive absorption or of -excretion. Life decays; the organism progressively -alters, and thus is constituted that state of decrepitude -by atrophy or chemical modification -which we call senescence, and which ends in death. -To sum up, old age and death may be attributed to -cellular differentiation.</p> - -<p><i>Possible Alimentary Rejuvenescence of the Differentiated -Cells—Conditions of Medium.</i>—We must add, -however—as the teaching of experiments in general -and in particular as the teaching of the experiments -of Loeb and of Calkins—that a slight change of the -environment, made at the right time, is capable of -re-establishing equilibrium and of completely rejuvenating -the infusorian. Senescence has not in -this case a definitive any more than an intrinsic -character; a modification in the composition of the -alimentary medium will successfully resist it. If we -are allowed to generalize this result, it may be said -that senescence, the declining trajectory, the evolution -step by step down to death, are not for the -cells considered in isolation an inevitable and essentially -inherent in the organism, and a rigorous consequence -of life itself. They preserve an accidental -character. In senescence and death there is no -really natural, internal cause, inexorable, and irremediable, -as was claimed in the past by J. Müller, -and more recently by Cohnheim in Germany and -Sedgwick Minot in America.</p> - -<p><i>Conditions of the Medium for Immortal Cells.</i>—As -for the cells which are less differentiated, the proto<span class="pagenum" id="Page_342">[Pg 342]</span>phytes -and the protozoa situated one degree lower in -the scale than the infusoria, we must admit the -possibility of that perfect and continuous equilibrium -which would save them from senile decrepitude. -And it is quite understood that this privilege remains -subordinated to the perfect constancy of the -appropriate medium. If the latter changes, the -equilibrium is broken, the small insensible perturbations -of nutrition accumulate, vital activity -decays, and in sole consequence of the imperfection -of the extrinsic conditions or of the medium, the -living being finds itself once more dragged down to -decay and to death.</p> - -<p><i>Immortal Elements of the Metazoa.</i>—All the preceding -facts and considerations refer to isolated cells, -to monocellular beings. But, and this is what makes -these truths so interesting, they may be extended to -all cells grouped in collectivity—i.e., to all the -animals and living beings that we know. In the -complicated edifice of the organism, the anatomical -elements, at any rate the least differentiated, would -have a continual brevet of immortality. Generally -speaking, this would be the case for the egg, for the -sexual elements, and perhaps, too, for the white -globules of the blood, the leucocytes. And, further, -around each of these elements must be realized the -invariably perfect medium which is the necessary -condition. This does not take place.</p> - -<p><i>Elements in Accidental and Remediable Death.</i>—As -for the other elements, they are like the infusoria, -but without the resource of conjugation. The -ambient medium becomes exhausted and intoxicated -around each cell, in consequence of the accidents -which happen to the other cells. Each therefore<span class="pagenum" id="Page_343">[Pg 343]</span> -undergoes progressive decay, and finally they -perish—the decay and destruction being perhaps -in principle accidental, but, in fact, they are the -rule.</p> - -<p>The different anatomical elements of the organism -are more or less sensitive to those perturbations which -cause senescence, necrobiosis, and death. There are -some more fragile and more exposed. Some are -more resisting, and finally, there are some which -are really immortal. We have just said that the -sexual cell, the ovum, is one. It follows that the -metazoan, man for instance, cannot entirely die. -Let us consider one of these beings. Its ancestors, -so to speak, have not entirely disappeared; each has -left the fertile egg, the surviving element from which -has issued the being of which we speak; and when -it in its turn has developed, part of that ovum has -been placed in reserve for a new generation. The -death of the elements is not therefore universal. -The metazoan is divided from the beginning into -two parts. On the one hand are the cells destined -to form the body, <i>somatic</i> cells. They will die. On -the other hand are the <i>reproductive</i>, or <i>germinal</i>, or -<i>sexual</i> cells, capable of living indefinitely.</p> - -<p><i>Somatic and Sexual Cells.</i>—In this sense we may -say with Weismann that there are two things in -the animal and in man—the one mortal, the <i>soma</i> -the body, the other immortal, the <i>germen</i>. These -germinal cells, as in the case of the protozoa we -mentioned above, possess a conditional immortality. -They are imperishable, but on the contrary, are -fragile and vulnerable. Millions of ova are destroyed -and are disappearing every moment. They may die -by accident, but never of old age.</p> - -<p><span class="pagenum" id="Page_344">[Pg 344]</span></p> - -<p>We now understand that if the protistae are -immortal, it is because these living beings, reduced -to a single cell, accumulate in it the compound -characters of the somatic cell and germinal cell, -and enjoy the privilege which is attached to the -latter.</p> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_345">[Pg 345]</span></p> - -<h3 class="nobreak" id="CHAPTER_VII_5">CHAPTER VII.<br /> - -<small>MAN. THE INSTINCT OF LIFE AND THE INSTINCT -OF DEATH.</small></h3></div> - - -<p class="prel">The miseries of humanity: 1. Disease; 2. Old age.—Old age -considered as a chronic disease.—Its occasional cause.—3. -The disharmonies of human nature; 4. The instinct of life -and the instinct of death.</p> - - -<p>Man’s unhappy plight is the constant theme of -philosophies and religions. Without referring to its -moral basis, it has a physical basis due to four -causes—the physical imperfection or disharmony of -nature, disease, old age, and death—or rather of -three, for what we call old age is perhaps a simple -disease. These are the great sorrows of man, the -sources of all his woes. Disease attacks him, old age -awaits him, and death must tear him from all the -ties which he has formed. All his pleasures are -poisoned by the certain knowledge that they last -but for a moment, that they are as precarious as his -health, his youth, and his life itself.</p> - - -<h4>§ 1. <span class="smcap">Disease.</span></h4> - -<p>Disease, frequent, constant, and inevitable as it is, -is, however, nothing but a fact outside the natural -order. Its character is clearly accidental, and it -interrupts the normal cycle of evolution. Medical<span class="pagenum" id="Page_346">[Pg 346]</span> -observation teaches us, on the other hand, that the -health of the body reacts on that of the mind; and -therefore man as a whole, moral and physical, is -affected by disease. Bacon described a diseased -body as a jailer to the soul, and the healthy body as -a host. Pascal recognized in diseases a principle of -error. “They spoil our judgment and our senses.”</p> - -<p>I am not expressing a chimerical hope when I -predict that science will conquer disease. Medicine -has at last issued from the contemplative attitude -of so many centuries; it has engaged in the -struggle, and signs of victory are already appearing. -Disease is no longer the mysterious power which it -was impossible to escape. Pasteur gave to it a body. -The microbe can be caught. In the words of -Schopenhauer, an alteration of the atmosphere so -slight that it is impossible to detect it by chemical -analysis may bring on cholera, yellow fever, the -black plague, diseases which carry off thousands of -men; and a slightly greater alteration might endanger -all life. The at once mysterious and terrifying spectacle -of the cholera at Berlin in 1831 had such an -effect on the philosopher that he fled in terror to -Frankfort. It has been said that this was the origin -of his pessimism, and that but for this he would have -continued to teach idealistic philosophy in some -Prussian university. L. Hartmann, another celebrated -leader of contemporary pessimism, has also -said that disease will always be beyond the resources -of medicine. Facts have given the lie to these -sombre prognostics. The microbic origin of most infectious -diseases has been recognized. The discovery -of attenuated poisons and serums has diminished -their gravity. An exact knowledge of methods of<span class="pagenum" id="Page_347">[Pg 347]</span> -contagion has enabled us to erect against them impregnable -barriers. Cholera, yellow fever, the plague -knock in vain at our doors. Diphtheria, dreaded by -every mother, has partially lost its deadly character. -Puerperal fever and blindness of the new-born child -are tending to disappear. Legend tells us that -Buddha in his youth, frightened at the sight of a -sick man, expressed in his father’s presence the wish -to be always in perfect health and sheltered from -disease. The King answered: “My son! you are -asking the impossible.” But it is towards the -realization of this impossibility that we are on our -way. Science is repelling the attacks of disease.</p> - - -<h4>§ 2. <span class="smcap">Old Age.</span></h4> - -<p>Old age is another sorrow of humanity. The -stage of existence in which the strength grows less -and never grows greater, and in which a thousand -infirmities appear, is not, however, a stage universal -in animals. Most of them die without our perceiving -in them any apparent signs of senile weakness. On -the other hand, some vegetables exhibit these signs. -Some trees are old; but it is in birds and mammals -that this decay, with the train of evils which accompanies -it, becomes a very marked phase of existence. -In man to debility is added a bodily shrinkage, grey -hairs, withered skin, and the wearing out and loss of -teeth. The exhausted and atrophied organism offers -a favourable field to all intercurrent diseases and to -every cause of destruction. It is this discrepitude -which makes old age so hateful. All desire to be -old, said Cicero; and when they are old, they say -that old age has come quicker than they expected.<span class="pagenum" id="Page_348">[Pg 348]</span> -La Bruyère expresses it in an apothegm, “We want -to grow old, and we fear old age.” One would like -longevity without old age.</p> - -<p>But can life be prolonged without senility diminishing -its value? Metchnikoff thinks it can. He -more or less clearly catches a glimpse of a normal -evolution of existence which would make it longer -and nevertheless exempt from senile decay.</p> - -<p>It is remarkable that we have so few scientific data -on the old age of man, and we have still fewer on -that of animals. The biologist knows no more than -the layman. The old age of the dog is betrayed by -its gait. Its coat loses its lustre, just as in disease. -The hair whitens around the forehead and the -muzzle. The teeth grow blunt and drop out. The -character loses its gaiety and becomes gloomy; the -animal becomes indifferent. He ceases to bark, and -often becomes blind and deaf.</p> - -<p>It is admitted that senile degeneration is due to an -alteration affecting most of the tissues. The cells, -the special anatomical elements of the liver, the -kidney, and the brain are reduced by atrophy and -degeneration. At the same time, the conjunctive -woof which serves them as a support develops, on -the contrary, at the expense in a measure of the -higher elements. For this reason the tissues harden. -We know that the flesh of old animals is tough. We -know in pathology that this is happening to the -tissues. It is due to growth, to injury to the -active and important elements, to the elements of -support of the organs. They form a tissue sometimes -called packed tissue, to show its secondary rôle -with reference to the elements which are deposited -in it. This kind of degeneration of the organs is<span class="pagenum" id="Page_349">[Pg 349]</span> -known as sclerosis. It constitutes the characteristic -lesion of a certain number of chronic diseases; and -these diseases are serious, for the stifling of the -characteristic elements by the less important elements -of the conjunctive or packed tissue results in -the more or less complete reduction or suppression -of the function.</p> - -<p>The blood vessels also undergo this transformation, -and what we may call universal trouble and danger -ensue. This sclerosis of the arteries, this arterio-sclerosis, -not only deprives the walls of the blood -vessels of the suppleness and elasticity which are -necessary for the proper irrigation of the organs, but -it makes them more fragile. Thus it becomes a -cause of hemorrhage, which is a very serious matter -as far as the brain and lungs are concerned.</p> - -<p>It is remarkable that the alteration of the tissues -during old age should be exactly similar to this. -This is inferred from the few researches that have -been made on the subject—from those of Demange -in 1886, of Merkel in 1891, and finally from the -researches of Metchnikoff himself. It is a generalized -sclerosis. As its consequence we have the lowering -of the proper activity of the organs and the danger -of cerebral hemorrhage created by arterio-sclerosis. -The transformations of the tissues in old men are -therefore summed up in the atrophy of the important -and specific elements of the tissues, and their replacement -by the hypertrophied conjunctive tissue. This -sclerosis is comparable to that of chronic diseases; -it is a pathological condition. Thus old age, as we -understand it, is a chronic disease and not a normal -phase of the vital cycle.</p> - -<p>On the other hand, if we ask ourselves what is the<span class="pagenum" id="Page_350">[Pg 350]</span> -origin of the scleroses which engender chronic -diseases, we find that they are due to the action of -various poisons, among which syphilitic poison and -the immoderate use of alcohol take the first place. -These are also the usual causes of senile degeneration. -But there must be some other, some very -general cause to explain the universality of the -process of senescence. Metchnikoff thinks that he -has found this cause in the microbes which swarm in -man’s digestive tube, particularly in the large intestine. -Their number is enormous. Strassburger -has given an approximate calculation, but words fail -to express it. We have to imagine a figure followed -by fifteen zeros. This microbic flora is composed of -“bacilli” and of “cocci,” and comprises a third of -the rejected matter. It produces slow poisons, -which, being at once reabsorbed, pass into the blood -and provoke the constant irritation from which -results arterio-sclerosis and the universal sclerosis -of old age. Instead of enjoying a healthy and -normal old age, in which the faculties of ripening -years are preserved, we drag out a diminished life, -a kind of chronic disease, which is ordinary old age. -This is due, according to Metchnikoff, to the parasitism -and the symbiosis of microbic flora, lodged in -a part of the economy in which it finds all the conditions -favourable to its prolific expansion. Such is -the specious theory, held to the verge of intrepidity, -by which this investigator explains the misery of our -old age, and which inspires him with the idea of a -remedy. For his observations conclude with a -régime, a series of prescriptions by which the author -fancies that life may be lengthened and the evils of -old age swept from our path. The dangerous flora<span class="pagenum" id="Page_351">[Pg 351]</span> -must be transformed into a cultivated and selected -flora. Although the organ in question may be of -doubtful utility, and although its existence, the -legacy of atavic heredity, must be considered as a -disharmony of human nature, Metchnikoff does not -go so far as to propose that it should be cut away, -and that we should call in surgery to assist in making -mankind perfect! But the rational means he proposes -will be endorsed by the most judicious students -of hygiene; and their effect, if it is not as wonderful -as one hopes for, cannot fail to ameliorate the -conditions of old age and make it more vigorous.</p> - - -<h4>§ 3. <span class="smcap">Disharmonies in Human Nature.</span></h4> - -<p>Another misery in the condition of man is due to -the dissidencies of his nature—that is to say, to his -physical imperfections and the discordancies which -exist between the physiological functions and the -instincts which should regulate them.</p> - -<p>This discordance reigns throughout the physical -organism. The body of man is not the perfect -masterpiece it was once supposed to be. It is -encumbered with annoying inutilities, with rudimentary -organs that have neither rôle nor function, -unfinished sketches which nature has left in the -different parts of his body. Such are the lachrymal -caruncle, a vestige of the third eyebrow in mammals; -the extrinsic muscles of the ear; the pineal gland of -the brain, which is only the rudiment of an ancestral -organ; the third eye, or the Cyclopean eye of the -saurians. The list is interminable. Wiedersheim has -counted in man 107 of these abortive hereditary -organs, the useless vestiges of organs useful to our<span class="pagenum" id="Page_352">[Pg 352]</span> -remote animal ancestors, atrophied in the course of -ages in consequence of modifications that have taken -place in the external medium.</p> - -<p>These rudimentary organs are not only useless; -they are often positively harmful.</p> - -<p>But the most serious discordance is that which -exists between the physiological functions and the -instincts which regulate them. In a well-regulated -organism slowly developed by adaptation the instincts -and the organs alike should be in relation with the -functions. All really natural acts are solicited by -an instinct, the satisfaction of which is at once a -need and a pleasure. The maternal instinct is -awakened at the proper moment in animals, and it -disappears as soon as the offspring requires no more -assistance. A craving for milk is shown in all newborn -children, and often disappears at an early age.</p> - -<p>Nature has endowed man as well as the other -animals with peculiar instincts, destined to preside -over the different functions and to ensure their -accomplishment. And, at the same time, it has -enabled him in a measure to deceive those instincts -and to satisfy them by other means than the execution -of the physiological acts with a view to which -they exist. Love and the instinct of reproduction -exist in man before the age of puberty. Canova felt -the spur of love at the age of five. Dante was in -love with Beatrice at nine; and Byron, then scarcely -seven, was already in love with Maria Duff. On the -other hand, puberty has no necessary relation to the -general maturity of the organism.</p> - -<p>The family instinct is subject to the same aberrations. -Man limits the number of his children. The<span class="pagenum" id="Page_353">[Pg 353]</span> -Turks of to-day follow the ancient Greeks in the -practice of abortion. Plato approved of the custom, -and Aristotle sanctioned its general prevalence. In -the province of Canton the Chinese of the agricultural -classes kill two-thirds of their girl children, -and the same is done at Tahiti. All these customs -co-exist with the perfect love and tender care of the -living children.</p> - -<p>Because of these different discordancies the physical -life of man is insufficiently regulated by nature. -Neither the physiological instinct, nor the family -instinct, nor the social instinct is, in general, sufficiently -imperative and precise. Hence, since the -internal impulse has not sufficient power, the necessity -arises for a rule of conduct exercising its influence -from without. Philosophies, religions, and legislation -have provided for this. They have regulated man’s -hygiene and the carrying out of his different physiological -functions. Their control has, moreover, had -its hygienic side. The scientific hygiene of to-day -has inherited their rôle.</p> - -<p>The idea of the fundamental perversity of human -nature is born of our cognizance of its discordancies, -unduly amplified and exaggerated. Soul and body -have been considered as distinctly discordant and -hostile elements. The body, the shroud of the soul, -the temporary host, the prison, the present source of -miseries, has been subjected to every kind of mortification. -Asceticism has treated the body and all the -innate instincts as our mortal foes.</p> - -<p>This suspicion, this depreciation of human nature -was the great error of the mystics. This view was -as fatal as the inverse view of pagan antiquity. -The model of the perfect life according to Greek<span class="pagenum" id="Page_354">[Pg 354]</span> -philosophy is a life in conformity with nature. To -aim at the harmonious development of man was the -precept of the ancient Academy, formulated by Plato. -The Stoics and the Epicureans had adopted the same -principle. Physical nature is considered as good. -It gives us the type, the rule, and the measure. The -moral rule itself is exactly appropriate to the physical -nature. We may say that pagan morality was -hygiene, the hygiene of the soul and the body alike; -the <i>mens sana in corpore sano</i> gave individual and -social direction. The Rationalists, the philosophers -of the eighteenth century, such as Baron d’Holbach -and later W. Von Humboldt, Darwin, and Herbert -Spencer, have adopted analogous views. If these -views have been contested, it is because of the imperfections -or aberrations of the natural instincts of -man. Also, if we wish to base individual family or -social morality on the natural instincts of man, it -must be specified that these instincts are to be -regularized. We must necessarily appeal from the -imperfect instincts of the present to the perfected -instincts of the future. Their perfection, moreover, -will only be a more exact approximation to the real -nature of man, and he, having avoided by the aid of -science the accidents which cause disease and senile -decrepitude, will enjoy a healthy youth and an ideal -old age.</p> - -<p>The reason of the discrepancies between instinct -and function in man is given by the natural history -of his development. We know that man has within -him original sin—his long atavism. He has sprung, -according to the transformists, from a simian stock. -He is a cousin, the successful relation, of a type -of antinomorphic monkeys, the chimpanzees. He<span class="pagenum" id="Page_355">[Pg 355]</span> -has “arrived,” they have remained undeveloped. -Probably he had a common ancestor with them, -some dryopithecan of an extinct species. From that -type sprang a new type already on the way to -progress, the <i>Pithecanthropus erectus</i>. Finally, the -anthropoid ancestor became one fine day the father -of a scion, clearly superior to himself, a miraculously -gifted being, man. Here, then, is no sign of the slow -evolution and gradual progress, which is the doctrine -held at present by Transformists. The Dutch -botanist De Vries has shown us, in fact, that nature -does leap: <i>natura facit saltus</i>. There would thus be -crises, as it were, in the life of species. At certain -critical epochs considerable differences of a specific -value appear in their offspring. It is at one of these -critical periods in the simian life that man has -appeared as the phenomenal child of an anthropoid. -He was born with a brain and an intellect superior -to those of his humble parents; and on the other -hand, he has inherited from them an organization -which is only inadequately adapted to the new conditions -of existence created by the development of -his sensitiveness and his brain power. This intellect -is not proportioned to his organization, which has -not developed at the same rate; it protests against -the discordances which adaptation has not yet had -time to efface. But it will efface them in the future.</p> - - -<h4>§ 4. <span class="smcap">The Instinct of Life and the Instinct -of Death.</span></h4> - -<p>The greatest discrepancy of this kind is the -knowledge of inevitable death without the instinct -which makes it longed for.<span class="pagenum" id="Page_356">[Pg 356]</span></p> - -<p>There are immortal animals. Man is not of the -number. He belongs, like all highly organized -beings, to the class of beings which have an end. -They die from accident or from disease. They -perish in the struggle with other animals, or with -microbes, or with external conditions. There are -certainly very few, if there are any, which die a -really natural death. And so it is with man. We -see old men gradually declining who appear to -doze gently off into the last sleep, and become -extinguished without disease, like a lamp whose oil -is exhausted. But this is in most cases only -apparently so. Besides the fact that the old age to -which they seemed to succumb is really a disease, -a generalized sclerosis, autopsy always reveals some -lesion more or less directly responsible for the fatal -issue.</p> - -<p>Man, like all the higher animals, is therefore -subject to the law of lethality. But while animals -have no idea of death and are not tormented by the -sentiment of their inevitable end, man knows and -understands this destiny. He has with the animals -the instinct of self-preservation, the instinct of life, -and at the same time the knowledge and the fear of -death. This contradiction, this discordance, is one -of the sources of his woes.</p> - -<p>Whether it be an accident or the regular term of -the normal cycle, death always comes too soon. It -surprises the man at a time when he has not yet -completed his physiological evolution; hence the -aversion and the terror it inspires. “We cannot -fix our eyes on the sun or on death,” said La Rochefoucauld. -The old man does not regard death with -less aversion than the young man. “He who is<span class="pagenum" id="Page_357">[Pg 357]</span> -most like the dead dies with most regret.” Man -knows that he is not getting his full measure.</p> - -<p>Further, all the really natural acts are solicited -by an instinct, the satisfaction of which is a need -and a joy. The need of death should therefore -appear at the end of life, just as the need of sleep -appears at the end of the day. It would appear, no -doubt, if the normal cycle of existence were fulfilled, -and if the harmonious evolution were not always -interrupted by accident. Death would then be -welcomed and longed for. It would lose its horror. -The instinct of death would replace at the wished -for moment the instinct of life. Man would pass -from the banquet of life with no other desire. He -would die without regret, “being old and full of -days,” according to the expression used in the Bible -in the case of Abraham, Isaac, and Jacob. No -doubt there are some analogies to this in the insects -which only assume the perfect form for the purpose -of procreation and immediately perish in their full -perfection. In these animals the approach of death -is blended with the intoxication of hymen. Thus -we see some of them, the ephemerae, lose at that -moment the instinct of life and the instinct of -self-preservation. They allow themselves to be -approached, taken, and seized, and make no effort -at flight.</p> - -<p>But what is this full measure of life which is -imparted to us? Metchnikoff holds that the ages -attributed to several persons in the Bible are very -probable. Abraham lived 175 years, Ishmael 137, -Joseph 110, Moses 120. Buffon believed in the -existence of a ratio between the longevity of animals -and the duration of their growth. He fixed it at<span class="pagenum" id="Page_358">[Pg 358]</span> -7:1. The animal whose development lasts two years -would thus have 14 years of life. This law would -give us 140 years, but the figure is too high, and -<a id="Flourens_has_reduced"></a>Flourens has reduced the ratio to that of 5:1, which -would still give us 100 years. Plato died in the act -of conversation at 81; Isocrates wrote his <i>Panathenaïcus</i> -at 94; Gorgias died in the full possession -of his intellect at 107.</p> - -<p>To reach the end of the promised longevity we -must neither count on the elixir of life nor on the -potable gold of the alchemists, nor on the stone of -immortality which did not prevent its inventor, -Paracelsus, from dying at the age of 58, nor on -transfusion, nor on Graham’s celestial bed, nor on -King David’s gerocomy, nor on any nostrum or -remedy. <i>Contra vim mortis non est medicamen in -hortis</i>, said the Salernian school. What Feuchtersleben -said is most true, “The art of prolonging life -consists in not cutting it short,” and it is a hygiene, -but a brilliant hygiene, such as that of which -Metchnikoff traces us the future lines, which will -realize the desires of nature.</p> - -<p>And now shall we find that physiology has solved -the enigma proposed by the Sphinx, and that it has -answered these poignant questions:—Whence do -we come? whither do we go? what is the end of -life? The end of life is, to the physiologist as well -as to Herbert Spencer, the tendency towards an -existence as full and as long as possible, towards a -life in conformity with real nature freed from the -discordancies which still remain; it is the accomplishment -of the harmonious cycle of our normal -evolution. This ideal human nature, without discordancies, -no longer vitiated as it is at present but<span class="pagenum" id="Page_359">[Pg 359]</span> -improved, will be the work of time and science. -Realized at last it will serve as a solid basis for -individual, family, and social morality. Healthy -youth fit for action; prolonged, adult age, the -symbol of strength; normal old age, wise in council, -these would have their natural places in harmonious -society. “Great actions,” said one of old, “are not -achieved by exertions of strength, or speed, or agility, -but rather by the prudence, the authority, and the -judgment which are found in a higher degree in old -age.” The old age of which Cicero here speaks is -the ideal old age, regular and normal, and not the -premature, deformed, incapable and egoistic old age -which results from a pathological condition. At the -end of this full life, the old man being full of days, -will crave for the eternal sleep and will resign -himself to it with joy....</p> - -<p>Death, then, “the last enemy that shall be -destroyed,” to use the expression of St. Paul, will -yield to the power of science. Instead of being -“the king of terrors,” it will become after a long -and healthy life, after a life exempt from morbid -accidents, a natural and longed for event, a satisfied -need. Then will be realized the wish of the -fabulist:—</p> - -<div class="blockquot"> - -<p>“<i>I should like to leave life at this age, just as one -leaves a banquet, thanking the host, and departing.</i>”</p> -</div> - -<p>Has this physiological solution of the problem of -death the virtue attributed to it by Metchnikoff? -Is it as optimistic as he thinks it is? The instinct -of death supervening at the end of a normal and -well-filled cycle will no doubt facilitate to the aged -their departure on the great voyage. The wrench<span class="pagenum" id="Page_360">[Pg 360]</span> -will no longer exist for the dead. Will it not exist -for those who are left behind? And since the -instinct of death can only exist about the time at -which death is expected, will the young man and -the man of ripened years look with less horror than -to-day at the law which cannot be escaped, when -they are in full possession of the instinct of life, -but warned of the inevitability of death?</p> - -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_361">[Pg 361]</span></p> - -<h3 class="nobreak" id="INDEX_OF_AUTHORS">INDEX OF AUTHORS.</h3> -</div> - -<ul class="index"> -<li class="ifrst">Altmann, <a href="#Page_258">258</a></li> - -<li class="indx">Anaxagoras, <a href="#Page_34">34</a></li> - -<li class="indx">Aquinas, St. Thomas, <a href="#Page_3">3</a>, <a href="#Page_19">19</a>, <a href="#Page_248">248</a></li> - -<li class="indx">Aristotle, <a href="#Page_3">3</a>, <a href="#Page_15">15</a>, <a href="#Page_18">18</a>, <a href="#Page_143">143</a>, <a href="#Page_146">146</a>, <a href="#Page_307">307</a></li> - -<li class="indx">Armstrong, <a href="#Page_295">295</a></li> - -<li class="indx">Atwater, <a href="#Page_137">137</a></li> - - -<li class="ifrst">Bacon, vi., <a href="#Page_35">35</a>, <a href="#Page_346">346</a></li> - -<li class="indx">Baker, <a href="#Page_233">233</a></li> - -<li class="indx">Balbiani, <a href="#Page_161">161</a>, <a href="#Page_165">165</a>, <a href="#Page_191">191</a>, <a href="#Page_206">206</a>-7, <a href="#Page_257">257</a></li> - -<li class="indx">Bang, d’Yvor, <a href="#Page_179">179</a></li> - -<li class="indx">Barthez, <a href="#Page_3">3</a>, <a href="#Page_19">19</a>, <a href="#Page_24">24</a></li> - -<li class="indx">Beclard, <a href="#Page_121">121</a></li> - -<li class="indx">Becquerel, <a href="#Page_278">278</a></li> - -<li class="indx">Beijerinck, <a href="#Page_193">193</a></li> - -<li class="indx">Benoit, <a href="#Page_271">271</a></li> - -<li class="indx">Bernard, Claude, vi., <a href="#Page_17">17</a>, <a href="#Page_27">27</a>, <a href="#Page_29">29</a>, <a href="#Page_32">32</a>, - <a href="#Page_48">48</a>, <a href="#Page_50">50</a>-4, <a href="#Page_107">107</a>, <a href="#Page_109">109</a>, <a href="#Page_112">112</a>, <a href="#Page_119">119</a>, <a href="#Page_148">148</a>, <a href="#Page_150">150</a>-1, <a href="#Page_171">171</a>, <a href="#Page_190">190</a>-2, <a href="#Page_194">194</a>, <a href="#Page_197">197</a>, <a href="#Page_204">204</a>, <a href="#Page_210">210</a>, <a href="#Page_214">214</a>-218, <a href="#Page_220">220</a> <i>et seq.</i>, <a href="#Page_310">310</a>, <a href="#Page_318">318</a></li> - -<li class="indx">Bernoulli, John, <a href="#Page_35">35</a>, <a href="#Page_73">73</a></li> - -<li class="indx">Bert, Paul, <a href="#Page_194">194</a></li> - -<li class="indx">Berthelot, <a href="#Page_91">91</a>, <a href="#Page_98">98</a>, <a href="#Page_128">128</a>-130, <a href="#Page_152">152</a>, <a href="#Page_204">204</a>, <a href="#Page_296">296</a></li> - -<li class="indx">Berthollet, <a href="#Page_82">82</a></li> - -<li class="indx">Berzelius, <a href="#Page_117">117</a></li> - -<li class="indx">Bichat, <a href="#Page_3">3</a>, <a href="#Page_6">6</a>, <a href="#Page_20">20</a>, <a href="#Page_22">22</a>, <a href="#Page_27">27</a>-30, <a href="#Page_35">35</a>, <a href="#Page_55">55</a>, <a href="#Page_158">158</a>, <a href="#Page_170">170</a>, <a href="#Page_198">198</a>, <a href="#Page_308">308</a></li> - -<li class="indx">Blumenbach, <a href="#Page_46">46</a></li> - -<li class="indx">Boë, Sylvius Le, <a href="#Page_35">35</a>-6</li> - -<li class="indx">Boerhaave, <a href="#Page_35">35</a>, <a href="#Page_147">147</a>, <a href="#Page_245">245</a></li> - -<li class="indx">Bohr, <a href="#Page_29">29</a>-30</li> - -<li class="indx">Bokorny, <a href="#Page_324">324</a></li> - -<li class="indx">Boltzmann, <a href="#Page_265">265</a></li> - -<li class="indx">Bonnet, <a href="#Page_23">23</a>, <a href="#Page_49">49</a></li> - -<li class="indx">Bordeu, <a href="#Page_3">3</a>, <a href="#Page_10">10</a>, <a href="#Page_19">19</a>, <a href="#Page_22">22</a>, <a href="#Page_24">24</a>, <a href="#Page_312">312</a></li> - -<li class="indx">Borelli, <a href="#Page_35">35</a></li> - -<li class="indx">Boscovitch, <a href="#Page_37">37</a>, <a href="#Page_248">248</a></li> - -<li class="indx">Bose, <a href="#Page_264">264</a></li> - -<li class="indx">Bossuet, <a href="#Page_11">11</a></li> - -<li class="indx">Bouasse, <a href="#Page_73">73</a>, <a href="#Page_264">264</a>-5</li> - -<li class="indx">Boullier, <a href="#Page_12">12</a></li> - -<li class="indx">Bourdeau, <a href="#Page_237">237</a>, <a href="#Page_242">242</a></li> - -<li class="indx">Boussingault, <a href="#Page_149">149</a></li> - -<li class="indx">Brandt, <a href="#Page_257">257</a></li> - -<li class="indx">Bravais, <a href="#Page_282">282</a></li> - -<li class="indx">Brillouin, <a href="#Page_264">264</a>, <a href="#Page_273">273</a></li> - -<li class="indx">Brown, <a href="#Page_266">266</a> <i>et seq.</i></li> - -<li class="indx">Brücke, <a href="#Page_44">44</a></li> - -<li class="indx">Büchner, <a href="#Page_325">325</a></li> - -<li class="indx">Buffon, <a href="#Page_46">46</a>, <a href="#Page_254">254</a>, <a href="#Page_357">357</a></li> - -<li class="indx">Bunge, von, <a href="#Page_3">3</a>, <a href="#Page_14">14</a></li> - -<li class="indx">Burdon, Sanderson, <a href="#Page_176">176</a></li> - -<li class="indx">Busquet, <a href="#Page_175">175</a></li> - -<li class="indx">Bütschli, <a href="#Page_161">161</a>-2, <a href="#Page_175">175</a></li> - - -<li class="ifrst">Cabanis, <a href="#Page_245">245</a>, <a href="#Page_246">246</a></li> - -<li class="indx">Cailletet, <a href="#Page_272">272</a></li> - -<li class="indx">Calkins, <a href="#Page_327">327</a>, <a href="#Page_338">338</a></li> - -<li class="indx">Calvert, <a href="#Page_271">271</a></li> - -<li class="indx">Candolle, <a href="#Page_20">20</a></li> - -<li class="indx">Cardan, <a href="#Page_261">261</a></li> - -<li class="indx">Carnot, <a href="#Page_72">72</a>-3, <a href="#Page_89">89</a>, <a href="#Page_92">92</a> <i>et seq.</i>, <a href="#Page_101">101</a>, <a href="#Page_114">114</a>, <a href="#Page_121">121</a></li> - -<li class="indx">Charpy, <a href="#Page_237">237</a>, <a href="#Page_271">271</a></li> - - -<li class="indx">Chauffard, <a href="#Page_3">3</a>, <a href="#Page_10">10</a>, <a href="#Page_11">11</a>, <a href="#Page_294">294</a></li> - -<li class="indx">Chauveau, <a href="#Page_75">75</a>, <a href="#Page_103">103</a>, <a href="#Page_108">108</a>, <a href="#Page_123">123</a>, <a href="#Page_130">130</a>, <a href="#Page_145">145</a>, <a href="#Page_213">213</a></li> - -<li class="indx">Chevreul, <a href="#Page_32">32</a></li> - -<li class="indx">Chossat, <a href="#Page_152">152</a></li> - -<li class="indx">Cicero, <a href="#Page_347">347</a>, <a href="#Page_359">359</a></li> - -<li class="indx">Clausius, <a href="#Page_67">67</a>, <a href="#Page_88">88</a></li> - -<li class="indx">Cohn, <a href="#Page_191">191</a>, <a href="#Page_252">252</a></li> - -<li class="indx">Cohnheim, <a href="#Page_341">341</a></li> - -<li class="indx">Colding, <a href="#Page_58">58</a> <i><a href="#Footnote_4">note</a></i>, <a href="#Page_90">90</a></li> - -<li class="indx">Colin, <a href="#Page_52">52</a></li> - -<li class="indx">Comte, <a href="#Page_189">189</a>-190, <a href="#Page_310">310</a></li> - -<li class="indx">Confucius, <a href="#Page_309">309</a></li> - -<li class="indx">Coulomb, <a href="#Page_76">76</a>, <a href="#Page_264">264</a>, <a href="#Page_273">273</a></li> - -<li class="indx">Crookes, <a href="#Page_295">295</a>, <a href="#Page_302">302</a></li> - -<li class="indx">Cuvier, <a href="#Page_3">3</a>, <a href="#Page_6">6</a>, <a href="#Page_27">27</a>-8, <a href="#Page_105">105</a>, <a href="#Page_120">120</a>, <a href="#Page_152">152</a>, <a href="#Page_190">190</a>, <a href="#Page_198">198</a>, <a href="#Page_308">308</a>, <a href="#Page_310">310</a>, <a href="#Page_319">319</a> -<span class="pagenum" id="Page_362">[Pg 362]</span></li> - - -<li class="indx">D’Alembert, <a href="#Page_20">20</a>, <a href="#Page_59">59</a> <i><a href="#Footnote_4">note</a></i>, <a href="#Page_90">90</a>, <a href="#Page_92">92</a></li> - -<li class="indx">Dantec, Le, <a href="#Page_48">48</a>, <a href="#Page_52">52</a>, <a href="#Page_55">55</a> <i><a href="#Footnote_3">note</a></i>, <a href="#Page_110">110</a>, <a href="#Page_148">148</a>, <a href="#Page_173">173</a>, <a href="#Page_198">198</a>, - <a href="#Page_201">201</a>, <a href="#Page_203">203</a>, <a href="#Page_213">213</a>, <a href="#Page_216">216</a>, <a href="#Page_220">220</a>, <a href="#Page_223">223</a> <i>et seq.</i>, <a href="#Page_231">231</a>, <a href="#Page_246">246</a>, <a href="#Page_261">261</a>, <a href="#Page_285">285</a>, <a href="#Page_296">296</a>, <a href="#Page_340">340</a></li> - -<li class="indx">D’Arsonval, <a href="#Page_126">126</a></li> - -<li class="indx">Darwin, <a href="#Page_3">3</a>, <a href="#Page_46">46</a>, <a href="#Page_167">167</a>, <a href="#Page_258">258</a>, <a href="#Page_354">354</a></li> - -<li class="indx">Dastre, A., <a href="#Page_192">192</a>, <a href="#Page_198">198</a> <i><a href="#Footnote_16">note</a></i></li> - -<li class="indx">Davy, Sir Humphry, <a href="#Page_61">61</a>, <a href="#Page_80">80</a></li> - -<li class="indx">Delafosse, <a href="#Page_282">282</a></li> - -<li class="indx">Delage, <a href="#Page_208">208</a></li> - -<li class="indx">Demange, <a href="#Page_349">349</a></li> - -<li class="indx">Democritus, <a href="#Page_34">34</a>, <a href="#Page_146">146</a></li> - -<li class="indx">Descartes, <a href="#Page_3">3</a>, <a href="#Page_9">9</a>, <a href="#Page_35">35</a>, <a href="#Page_37">37</a>, <a href="#Page_40">40</a>, <a href="#Page_73">73</a>, <a href="#Page_91">91</a>, <a href="#Page_98">98</a></li> - -<li class="indx">Despretz, <a href="#Page_126">126</a></li> - -<li class="indx">Diderot, <a href="#Page_245">245</a>, <a href="#Page_246">246</a></li> - -<li class="indx">Drechsel, <a href="#Page_183">183</a></li> - -<li class="indx">Dressel, <a href="#Page_20">20</a></li> - -<li class="indx">Dubois-Reymond, <a href="#Page_44">44</a>, <a href="#Page_58">58</a> <i><a href="#Footnote_5">note</a></i>, <a href="#Page_253">253</a></li> - -<li class="indx">Duclaux, <a href="#Page_119">119</a>, <a href="#Page_137">137</a>, <a href="#Page_184">184</a>, <a href="#Page_324">324</a></li> - -<li class="indx">Dufour, <a href="#Page_297">297</a></li> - -<li class="indx">Duguet, <a href="#Page_264">264</a></li> - -<li class="indx">Duhem, <a href="#Page_62">62</a>, <a href="#Page_264">264</a>, <a href="#Page_265">265</a></li> - -<li class="indx">Dulong, <a href="#Page_126">126</a></li> - -<li class="indx">Dumas, <a href="#Page_115">115</a>, <a href="#Page_149">149</a>, <a href="#Page_151">151</a>-2</li> - - -<li class="ifrst">Epicurus, <a href="#Page_35">35</a>, <a href="#Page_146">146</a></li> - -<li class="indx">Ehrlich, <a href="#Page_176">176</a></li> - -<li class="indx">Errera, <a href="#Page_52">52</a>, <a href="#Page_193">193</a>-4, <a href="#Page_237">237</a>, <a href="#Page_153">153</a>, <a href="#Page_295">295</a>, <a href="#Page_302">302</a> <i>et seq.</i></li> - -<li class="indx">Euclid, v.</li> - - -<li class="ifrst">Faye, <a href="#Page_260">260</a></li> - -<li class="indx">Feuchterslehen, <a href="#Page_358">358</a></li> - -<li class="indx">Flemming, <a href="#Page_161">161</a></li> - -<li class="indx">Flourens, <a href="#Page_20">20</a>-1, <a href="#Page_152">152</a>, <a href="#Page_208">208</a>, <a href="#Page_306">306</a>, <a href="#Page_358">358</a></li> - -<li class="indx">Fouillée, <a href="#Page_242">242</a></li> - -<li class="indx">Fromann, <a href="#Page_161">161</a></li> - -<li class="indx">Fuerth, <a href="#Page_183">183</a></li> - - -<li class="ifrst">Galen, <a href="#Page_25">25</a>, <a href="#Page_55">55</a>, <a href="#Page_143">143</a></li> - -<li class="indx">Galeotti, <a href="#Page_180">180</a></li> - -<li class="indx">Galileo, <a href="#Page_73">73</a>, <a href="#Page_91">91</a>, <a href="#Page_98">98</a>, <a href="#Page_197">197</a>, <a href="#Page_241">241</a>, <a href="#Page_260">260</a></li> - -<li class="indx">Gardair, <a href="#Page_19">19</a>, <a href="#Page_248">248</a></li> - -<li class="indx">Gautier, A., <a href="#Page_3">3</a>, <a href="#Page_32">32</a>, <a href="#Page_36">36</a>, <a href="#Page_39">39</a>, <a href="#Page_176">176</a>, <a href="#Page_233">233</a>, <a href="#Page_324">324</a></li> - -<li class="indx">Gernez, <a href="#Page_237">237</a>, <a href="#Page_288">288</a>, <a href="#Page_295">295</a> <i>et seq.</i></li> - -<li class="indx">Glisson, <a href="#Page_27">27</a></li> - -<li class="indx">Goethe, <a href="#Page_170">170</a>, <a href="#Page_312">312</a></li> - -<li class="indx">Gouy, <a href="#Page_266">266</a>, <a href="#Page_268">268</a></li> - -<li class="indx">Grimaud, <a href="#Page_19">19</a></li> - -<li class="indx">Gruber, <a href="#Page_165">165</a>, <a href="#Page_206">206</a>, <a href="#Page_257">257</a></li> - -<li class="indx">Guignard, <a href="#Page_161">161</a></li> - -<li class="indx">Guillaume, <a href="#Page_237">237</a>, <a href="#Page_262">262</a>, <a href="#Page_264">264</a>, <a href="#Page_271">271</a>, <a href="#Page_277">277</a></li> - -<li class="indx">Guillemin, <a href="#Page_237">237</a></li> - -<li class="indx">Guldberg, <a href="#Page_83">83</a></li> - - -<li class="ifrst">Harbermann, <a href="#Page_183">183</a></li> - -<li class="indx">Haeckel, <a href="#Page_3">3</a>, <a href="#Page_46">46</a>, <a href="#Page_164">164</a>, <a href="#Page_167">167</a>, <a href="#Page_246">246</a>, <a href="#Page_251">251</a></li> - -<li class="indx">Hales, <a href="#Page_43">43</a></li> - -<li class="indx">Haller, <a href="#Page_27">27</a></li> - -<li class="indx">Hamilton, Sir W. Rowan, <a href="#Page_67">67</a></li> - -<li class="indx">Hammarsten, <a href="#Page_180">180</a></li> - -<li class="indx">Hartmann, <a href="#Page_276">276</a>, <a href="#Page_346">346</a></li> - -<li class="indx">Harvey, <a href="#Page_43">43</a>, <a href="#Page_160">160</a></li> - -<li class="indx">Haüy, <a href="#Page_282">282</a></li> - -<li class="indx">Hegel, <a href="#Page_170">170</a>, <a href="#Page_331">331</a></li> - -<li class="indx">Heidenhain, <a href="#Page_3">3</a>, <a href="#Page_29">29</a>, <a href="#Page_30">30</a>-1</li> - -<li class="indx">Heitzmann, <a href="#Page_161">161</a></li> - -<li class="indx">Helmholtz, <a href="#Page_44">44</a>, <a href="#Page_56">56</a>, <a href="#Page_58">58</a>, <a href="#Page_67">67</a>, <a href="#Page_90">90</a>, <a href="#Page_97">97</a>, <a href="#Page_99">99</a>, <a href="#Page_252">252</a></li> - -<li class="indx">Helmont, van, <a href="#Page_3">3</a>, <a href="#Page_21">21</a>, <a href="#Page_26">26</a>, <a href="#Page_33">33</a>, <a href="#Page_146">146</a>, <a href="#Page_250">250</a></li> - -<li class="indx">Henninger, <a href="#Page_302">302</a></li> - -<li class="indx">Heraclitus, <a href="#Page_34">34</a></li> - -<li class="indx">Hertwig, <a href="#Page_167">167</a></li> - -<li class="indx">Hertz, <a href="#Page_88">88</a></li> - -<li class="indx">Hess, <a href="#Page_91">91</a>, <a href="#Page_98">98</a></li> - -<li class="indx">Hippocrates, <a href="#Page_146">146</a></li> - -<li class="indx">Hirn, <a href="#Page_126">126</a></li> - -<li class="indx">His, <a href="#Page_46">46</a></li> - -<li class="indx">Hlasitwetz, <a href="#Page_183">183</a></li> - -<li class="indx">Holbach, d’, <a href="#Page_354">354</a></li> - -<li class="indx">Hoogewerf, <a href="#Page_303">303</a></li> - -<li class="indx">Hopkinson, <a href="#Page_271">271</a></li> - -<li class="indx">Humboldt, W. von, <a href="#Page_354">354</a></li> - - -<li class="ifrst">Ingenhousz, <a href="#Page_115">115</a></li> - -<li class="indx">Izolet, <a href="#Page_247">247</a></li> - - -<li class="ifrst">Joule, <a href="#Page_53">53</a> <i>note</i>, <a href="#Page_90">90</a>-1, <a href="#Page_93">93</a>, <a href="#Page_133">133</a> <i>et seq.</i>, <a href="#Page_143">143</a>, <a href="#Page_152">152</a></li> - - -<li class="ifrst">Kant, <a href="#Page_312">312</a>, <a href="#Page_319">319</a></li> - -<li class="indx">Kaup, <a href="#Page_213">213</a></li> - -<li class="indx">Kaufmann, <a href="#Page_126">126</a></li> - -<li class="indx">Kelvin, Lord, <a href="#Page_63">63</a>, <a href="#Page_67">67</a>, <a href="#Page_90">90</a>, <a href="#Page_92">92</a>, <a href="#Page_251">251</a>-2, <a href="#Page_264">264</a>;</li> -<li class="isub1">and the idea of energy, <a href="#Page_66">66</a></li> - -<li class="indx">Kepler, <a href="#Page_29">29</a>, <a href="#Page_241">241</a></li> - -<li class="indx">Klemm, <a href="#Page_323">323</a></li> - -<li class="indx">Koelliker, <a href="#Page_160">160</a> -<span class="pagenum" id="Page_363">[Pg 363]</span></li> - -<li class="indx">Kossel, <a href="#Page_174">174</a>, <a href="#Page_179">179</a>, <a href="#Page_130">130</a>-1, <a href="#Page_136">136</a> <i>et seq.</i></li> - -<li class="indx">Kuhne, <a href="#Page_45">45</a></li> - -<li class="indx">Kuhm, <a href="#Page_216">216</a></li> - -<li class="indx">Kuliabko, <a href="#Page_23">23</a>, <a href="#Page_311">311</a></li> - -<li class="indx">Kunstler, <a href="#Page_157">157</a>, <a href="#Page_161">161</a>-2, <a href="#Page_175">175</a></li> - -<li class="indx">Kuppfer, <a href="#Page_161">161</a></li> - - -<li class="ifrst">Lammettrie, <a href="#Page_147">147</a></li> - -<li class="indx">Lamarck, <a href="#Page_46">46</a></li> - -<li class="indx">Lapparent, <a href="#Page_284">284</a></li> - -<li class="indx">Lapicque, <a href="#Page_140">140</a>, <a href="#Page_145">145</a></li> - -<li class="indx">Langley, <a href="#Page_216">216</a></li> - -<li class="indx">Laplace, <a href="#Page_43">43</a>, <a href="#Page_63">63</a>, <a href="#Page_126">126</a>, <a href="#Page_260">260</a></li> - -<li class="indx">Laulanié, <a href="#Page_103">103</a></li> - -<li class="indx">Laurie, <a href="#Page_271">271</a></li> - -<li class="indx">La Rochefoucauld, <a href="#Page_356">356</a></li> - -<li class="indx">Lavoisier, <a href="#Page_3">3</a>, <a href="#Page_28">28</a>, <a href="#Page_30">30</a>, <a href="#Page_36">36</a>, <a href="#Page_43">43</a>, <a href="#Page_65">65</a>, <a href="#Page_117">117</a>, <a href="#Page_121">121</a>, <a href="#Page_126">126</a>, <a href="#Page_128">128</a>, <a href="#Page_143">143</a>, <a href="#Page_176">176</a>, <a href="#Page_296">296</a></li> - -<li class="indx">Lea, <a href="#Page_216">216</a></li> - -<li class="indx">Le Châtelier, <a href="#Page_85">85</a>, <a href="#Page_92">92</a></li> - -<li class="indx">Lechatelier, H. and A., <a href="#Page_271">271</a></li> - -<li class="indx">Lecocq de Boisbaudran, <a href="#Page_295">295</a></li> - -<li class="indx">Leeuwenhoek, <a href="#Page_232">232</a></li> - -<li class="indx">Lefèvre, <a href="#Page_126">126</a></li> - -<li class="indx">Legallois, <a href="#Page_21">21</a></li> - -<li class="indx">Leydig, <a href="#Page_161">161</a>-2</li> - -<li class="indx">Liebermeister, <a href="#Page_136">136</a></li> - -<li class="indx">Liebig, <a href="#Page_26">26</a>, <a href="#Page_53">53</a> <i>note</i>, <a href="#Page_117">117</a></li> - -<li class="indx">Lilienfeld, <a href="#Page_179">179</a>, <a href="#Page_247">247</a></li> - -<li class="indx">Locke, <a href="#Page_23">23</a></li> - -<li class="indx">Lodge, <a href="#Page_271">271</a></li> - -<li class="indx">Loeb, <a href="#Page_43">43</a>, <a href="#Page_167">167</a>, <a href="#Page_327">327</a>, <a href="#Page_341">341</a></li> - -<li class="indx">Loew, <a href="#Page_324">324</a></li> - -<li class="indx">Loisel, <a href="#Page_339">339</a>, <a href="#Page_341">341</a></li> - -<li class="indx">Lorry, <a href="#Page_21">21</a></li> - -<li class="indx">Longet, <a href="#Page_52">52</a></li> - -<li class="indx">Lowitz, <a href="#Page_297">297</a></li> - -<li class="indx">Loye, <a href="#Page_192">192</a></li> - -<li class="indx">Ludwig, <a href="#Page_44">44</a>, <a href="#Page_215">215</a></li> - - -<li class="ifrst">Mach, <a href="#Page_41">41</a>, <a href="#Page_62">62</a></li> - -<li class="indx">Magendie, <a href="#Page_43">43</a>, <a href="#Page_143">143</a></li> - -<li class="indx">Magy, <a href="#Page_37">37</a></li> - -<li class="indx">Malgaigne, <a href="#Page_153">153</a></li> - -<li class="indx">Mallard, <a href="#Page_284">284</a></li> - -<li class="indx">Marinesco, <a href="#Page_231">231</a>, <a href="#Page_328">328</a></li> - -<li class="indx">Markel, <a href="#Page_349">349</a></li> - -<li class="indx">Maspero, <a href="#Page_3">3</a>, <a href="#Page_234">234</a></li> - -<li class="indx">Matthiesson, <a href="#Page_271">271</a></li> - -<li class="indx">Maupas, <a href="#Page_337">337</a></li> - -<li class="indx">Maxwell, <a href="#Page_88">88</a></li> - -<li class="indx">Mayer, R., <a href="#Page_56">56</a>, <a href="#Page_58">58</a>, <a href="#Page_89">89</a>, <a href="#Page_90">90</a>, <a href="#Page_97">97</a>, <a href="#Page_99">99</a>, <a href="#Page_101">101</a></li> - -<li class="indx">Mering, von, <a href="#Page_133">133</a>, <a href="#Page_136">136</a></li> - -<li class="indx">Metchnikoff, <a href="#Page_327">327</a> <i>et seq.</i></li> - -<li class="indx">Miescher, <a href="#Page_174">174</a>, <a href="#Page_179">179</a></li> - -<li class="indx">Milne-Edwards, <a href="#Page_152">152</a>, <a href="#Page_195">195</a></li> - -<li class="indx">Minot, <a href="#Page_341">341</a></li> - -<li class="indx">Miura, <a href="#Page_137">137</a></li> - -<li class="indx">Mori, <a href="#Page_145">145</a></li> - -<li class="indx">Müller, <a href="#Page_20">20</a>, <a href="#Page_27">27</a>, <a href="#Page_341">341</a></li> - -<li class="indx">Murato, <a href="#Page_45">45</a></li> - - -<li class="ifrst">Naegeli, <a href="#Page_168">168</a></li> - -<li class="indx">Needham, <a href="#Page_46">46</a></li> - -<li class="indx">Newton, <a href="#Page_58">58</a> <i><a href="#Footnote_4">note</a></i>, <a href="#Page_70">70</a>, <a href="#Page_90">90</a>-1, <a href="#Page_93">93</a></li> - -<li class="indx">Noorden, van, <a href="#Page_129">129</a>, <a href="#Page_137">137</a>, <a href="#Page_140">140</a>, <a href="#Page_210">210</a></li> - -<li class="indx">Nussbaum, <a href="#Page_165">165</a>, <a href="#Page_206">206</a>, <a href="#Page_215">215</a>, <a href="#Page_217">217</a></li> - - -<li class="ifrst">Obermeyer, <a href="#Page_271">271</a></li> - -<li class="indx">Osmond, <a href="#Page_237">237</a>, <a href="#Page_271">271</a></li> - -<li class="indx">Ostwald, <a href="#Page_41">41</a>, <a href="#Page_62">62</a>, <a href="#Page_67">67</a>, <a href="#Page_85">85</a>, <a href="#Page_104">104</a>, <a href="#Page_237">237</a>, <a href="#Page_258">258</a>, <a href="#Page_289">289</a>, <a href="#Page_295">295</a> <i>et seq.</i></li> - - -<li class="ifrst">Paracelsus, <a href="#Page_26">26</a>, <a href="#Page_146">146</a>, <a href="#Page_312">312</a></li> - -<li class="indx">Pascal, <a href="#Page_74">74</a>, <a href="#Page_161">161</a></li> - -<li class="indx">Pasteur, <a href="#Page_53">53</a>, <a href="#Page_191">191</a>, <a href="#Page_222">222</a> <i>et seq.</i>, <a href="#Page_237">237</a>, <a href="#Page_250">250</a>, <a href="#Page_288">288</a>, <a href="#Page_346">346</a></li> - -<li class="indx">Payen, <a href="#Page_151">151</a></li> - -<li class="indx">Persoz, <a href="#Page_152">152</a></li> - -<li class="indx">Petit, <a href="#Page_180">180</a></li> - -<li class="indx">Pettenkofer, <a href="#Page_210">210</a></li> - -<li class="indx">Pfeffer, <a href="#Page_175">175</a>, <a href="#Page_193">193</a></li> - -<li class="indx">Pflüger, <a href="#Page_12">12</a>, <a href="#Page_56">56</a>, <a href="#Page_135">135</a>, <a href="#Page_144">144</a>, <a href="#Page_176">176</a>, <a href="#Page_210">210</a>, <a href="#Page_213">213</a></li> - -<li class="indx">Philpotts, <a href="#Page_46">46</a></li> - -<li class="indx">Pictet, <a href="#Page_233">233</a></li> - -<li class="indx">Pitcairn, <a href="#Page_35">35</a></li> - -<li class="indx">Plato, <a href="#Page_35">35</a>, <a href="#Page_307">307</a></li> - -<li class="indx">Plosz, <a href="#Page_180">180</a></li> - -<li class="indx">Poincaré, <a href="#Page_62">62</a></li> - -<li class="indx">Poisson, <a href="#Page_63">63</a></li> - -<li class="indx">Preyer, <a href="#Page_192">192</a>, <a href="#Page_252">252</a> <i>et seq.</i></li> - -<li class="indx">Priestley, <a href="#Page_115">115</a></li> - -<li class="indx">Ptolemy, v.</li> - -<li class="indx">Pythagoras, <a href="#Page_18">18</a></li> - - -<li class="ifrst">Rauber, <a href="#Page_237">237</a>, <a href="#Page_288">288</a></li> - -<li class="indx">Raulin, <a href="#Page_191">191</a></li> - -<li class="indx">Regnault, <a href="#Page_117">117</a></li> - -<li class="indx">Reinke, <a href="#Page_3">3</a>, <a href="#Page_32">32</a></li> - -<li class="indx">Renan, <a href="#Page_240">240</a></li> - -<li class="indx">Ribbert, <a href="#Page_208">208</a> -<span class="pagenum" id="Page_364">[Pg 364]</span></li> - -<li class="indx">Ribot, <a href="#Page_247">247</a></li> - -<li class="indx">Riche, <a href="#Page_271">271</a></li> - -<li class="indx">Richet, <a href="#Page_50">50</a>, <a href="#Page_126">126</a>, <a href="#Page_140">140</a></li> - -<li class="indx">Richter, <a href="#Page_252">252</a></li> - -<li class="indx">Rindfleisch, <a href="#Page_4">4</a></li> - -<li class="indx">Roberts-Austen, <a href="#Page_237">237</a>, <a href="#Page_271">271</a>-2</li> - -<li class="indx">Robin, <a href="#Page_62">62</a>, <a href="#Page_177">177</a></li> - -<li class="indx">Rosenthal, <a href="#Page_126">126</a></li> - -<li class="indx">Rouvier, <a href="#Page_160">160</a></li> - -<li class="indx">Roux, <a href="#Page_46">46</a>, <a href="#Page_165">165</a></li> - -<li class="indx">Rubner, <a href="#Page_129">129</a>, <a href="#Page_130">130</a>, <a href="#Page_140">140</a> <i>et seq.</i>, <a href="#Page_210">210</a></li> - -<li class="indx">Rumford, <a href="#Page_80">80</a></li> - - -<li class="ifrst">Sabatier, <a href="#Page_242">242</a></li> - -<li class="indx">Sachs, <a href="#Page_161">161</a>, <a href="#Page_194">194</a></li> - -<li class="indx">Salles-Guyon, <a href="#Page_252">252</a></li> - -<li class="indx">Sanderson, Burdon, <a href="#Page_176">176</a></li> - -<li class="indx">Scaliger, <a href="#Page_241">241</a></li> - -<li class="indx">Schleiden, <a href="#Page_159">159</a></li> - -<li class="indx">Schopenhauer, <a href="#Page_346">346</a></li> - -<li class="indx">Schwartz, <a href="#Page_162">162</a></li> - -<li class="indx">Schultze, <a href="#Page_160">160</a>, <a href="#Page_326">326</a></li> - -<li class="indx">Schultzenberger, <a href="#Page_174">174</a>, <a href="#Page_162">162</a> <i>et seq.</i></li> - -<li class="indx">Secchi, <a href="#Page_88">88</a></li> - -<li class="indx">Seguin, <a href="#Page_58">58</a> <i><a href="#Footnote_4">note</a></i>, <a href="#Page_90">90</a></li> - -<li class="indx">Senebier, <a href="#Page_115">115</a></li> - -<li class="indx">Siven, <a href="#Page_145">145</a></li> - -<li class="indx">Spallanzani, <a href="#Page_43">43</a>, <a href="#Page_233">233</a></li> - -<li class="indx">Spencer, Herbert, <a href="#Page_46">46</a>, <a href="#Page_247">247</a>, <a href="#Page_354">354</a>, <a href="#Page_358">358</a></li> - -<li class="indx">Spring, <a href="#Page_272">272</a></li> - -<li class="indx">Stahl, <a href="#Page_3">3</a>, <a href="#Page_9">9</a>, <a href="#Page_12">12</a>, <a href="#Page_35">35</a>, <a href="#Page_146">146</a></li> - -<li class="indx">Stammreich, <a href="#Page_137">137</a></li> - -<li class="indx">Stead, <a href="#Page_237">237</a></li> - -<li class="indx">Stohmann, <a href="#Page_129">129</a>, <a href="#Page_130">130</a>, <a href="#Page_140">140</a></li> - -<li class="indx">Strassburger, <a href="#Page_161">161</a>, <a href="#Page_350">350</a></li> - -<li class="indx">Swann, <a href="#Page_159">159</a></li> - -<li class="indx">Swift, <a href="#Page_262">262</a></li> - - -<li class="ifrst">Tait, <a href="#Page_53">53</a> <i>note</i>, <a href="#Page_66">66</a></li> - -<li class="indx">Tammann, <a href="#Page_237">237</a>, <a href="#Page_253">253</a>, <a href="#Page_295">295</a> <i>et seq.</i></li> - -<li class="indx">Thales, <a href="#Page_34">34</a></li> - -<li class="indx">Thomson, Sir J. J., <a href="#Page_279">279</a></li> - -<li class="indx">Tissot, <a href="#Page_12">12</a></li> - -<li class="indx">Tomlinson, <a href="#Page_264">264</a></li> - -<li class="indx">Trembley, <a href="#Page_22">22</a>, <a href="#Page_206">206</a></li> - -<li class="indx">Tsuboï, <a href="#Page_145">145</a></li> - -<li class="indx">Tylor, <a href="#Page_8">8</a></li> - - -<li class="ifrst">Verworn, <a href="#Page_206">206</a>, <a href="#Page_252">252</a>, <a href="#Page_257">257</a></li> - -<li class="indx">Violette, <a href="#Page_295">295</a></li> - -<li class="indx">Virchow, <a href="#Page_318">318</a>, <a href="#Page_326">326</a></li> - -<li class="indx">Voit, <a href="#Page_119">119</a>, <a href="#Page_133">133</a> <i>et seq.</i>, <a href="#Page_210">210</a></li> - -<li class="indx">Vries, de, <a href="#Page_46">46</a>, <a href="#Page_258">258</a>, <a href="#Page_355">355</a></li> - -<li class="indx">Vulpian, <a href="#Page_24">24</a></li> - - -<li class="ifrst">Waage, <a href="#Page_83">83</a></li> - -<li class="indx">Waller, <a href="#Page_47">47</a>, <a href="#Page_206">206</a></li> - -<li class="indx">Wallerant, <a href="#Page_282">282</a>-3</li> - -<li class="indx">Warburg, <a href="#Page_264">264</a></li> - -<li class="indx">Watt, <a href="#Page_76">76</a></li> - -<li class="indx">Weismann, <a href="#Page_46">46</a>, <a href="#Page_167">167</a>, <a href="#Page_336">336</a>, <a href="#Page_343">343</a></li> - -<li class="indx">Wertheim, <a href="#Page_264">264</a></li> - -<li class="indx">Whitman, <a href="#Page_46">46</a></li> - -<li class="indx">Widersheim, <a href="#Page_351">351</a></li> - -<li class="indx">Wiedermann, <a href="#Page_264">264</a></li> - -<li class="indx">Wiesner, <a href="#Page_167">167</a></li> - -<li class="indx">Willis, <a href="#Page_36">36</a>, <a href="#Page_147">147</a></li> - -<li class="indx">Winternitz, <a href="#Page_126">126</a></li> - - -<li class="ifrst">Yung, <a href="#Page_233">233</a></li> - - -<li class="ifrst">Zuntz, <a href="#Page_133">133</a>, <a href="#Page_136">136</a>, <a href="#Page_210">210</a></li> - -</ul> -<hr class="chap x-ebookmaker-drop" /> - -<div class="chapter"> -<p><span class="pagenum" id="Page_365">[Pg 365]</span></p> - -<h2 class="nobreak" id="INDEX_OF_SUBJECTS">INDEX OF SUBJECTS.</h2> -</div> - - - -<ul class="index"> -<li class="ifrst">Activity, functional and vital, <a href="#Page_106">106</a> <i>et seq.</i>, <a href="#Page_217">217</a> <i>et seq.</i></li> - -<li class="indx">Aerobia, <a href="#Page_193">193</a></li> - -<li class="indx">Age, old, Book v.</li> - -<li class="indx">Albumin, <a href="#Page_178">178</a></li> - -<li class="indx">Albuminoids, <a href="#Page_178">178</a></li> - -<li class="indx">Alcohol, <a href="#Page_136">136</a></li> - -<li class="indx">Alimentation, <a href="#Page_116">116</a> <i>et seq.</i></li> - -<li class="indx">Alloys, structure of, <a href="#Page_273">273</a></li> - -<li class="indx">Anærobia, <a href="#Page_193">193</a></li> - -<li class="indx">Animism, <a href="#Page_6">6</a>, <a href="#Page_7">7</a>, Chap. ii., <i>passim</i></li> - -<li class="indx">Annealing, <a href="#Page_275">275</a></li> - -<li class="indx">Apposition, <a href="#Page_291">291</a></li> - -<li class="indx">Archeus, the, <a href="#Page_25">25</a>, <a href="#Page_26">26</a>, <a href="#Page_33">33</a></li> - -<li class="indx">Arginin, <a href="#Page_187">187</a></li> - -<li class="indx">Assimilation, law of functional, <a href="#Page_110">110</a>, <a href="#Page_213">213</a></li> - -<li class="indx">Atomicities, satisfied, <a href="#Page_185">185</a></li> - -<li class="indx">Atrophy, <a href="#Page_326">326</a></li> - -<li class="indx">Attraction, energy of position, <a href="#Page_64">64</a></li> - - -<li class="ifrst">Balance, sheet, nutritive, <a href="#Page_118">118</a></li> - -<li class="indx">Beliefs, primitive, <a href="#Page_239">239</a></li> - -<li class="indx">Bioblasts, <a href="#Page_253">253</a></li> - -<li class="indx">Biophors, <a href="#Page_167">167</a></li> - -<li class="indx">Blas, the, <a href="#Page_25">25</a>, <a href="#Page_33">33</a></li> - -<li class="indx">Blood, lavage of, <a href="#Page_192">192</a></li> - -<li class="indx">Brain, and death, <a href="#Page_315">315</a></li> - -<li class="indx">Butylic ferments, <a href="#Page_193">193</a></li> - -<li class="indx">Butyric ferments, <a href="#Page_193">193</a></li> - - -<li class="ifrst">Calorie, <a href="#Page_125">125</a> <i><a href="#Footnote_10">note</a></i></li> - -<li class="indx">Calorimeter, ice, <a href="#Page_126">126</a>;</li> -<li class="isub1">bomb, <a href="#Page_128">128</a></li> - -<li class="indx">Caprice, of Nature, <a href="#Page_45">45</a></li> - -<li class="indx">Cause, final, <a href="#Page_45">45</a></li> - -<li class="indx">Cells, <a href="#Page_48">48</a>, <a href="#Page_147">147</a>;</li> -<li class="isub1">somatic and sexual, <a href="#Page_343">343</a></li> - -<li class="indx">Cellular theory, <a href="#Page_158">158</a> <i>et seq.</i></li> - -<li class="indx">Centrosome, <a href="#Page_163">163</a></li> - -<li class="indx">Chromosome, <a href="#Page_165">165</a></li> - -<li class="indx">Cicatrization, <a href="#Page_287">287</a></li> - -<li class="indx">Complex, homogeneity of the, <a href="#Page_245">245</a></li> - -<li class="indx">Conductibility, <a href="#Page_26">26</a></li> - -<li class="indx">Consciousness, in brute bodies, <a href="#Page_244">244</a> <i>et seq.</i></li> - -<li class="indx">Continuity, principle of, <a href="#Page_242">242</a>, <a href="#Page_247">247</a></li> - -<li class="indx">Contractility, <a href="#Page_26">26</a></li> - -<li class="indx">Contraction, energy of static and dynamic, <a href="#Page_75">75</a></li> - -<li class="indx">Conservation, of energy, <a href="#Page_58">58</a>;</li> -<li class="isub1">of force, <a href="#Page_58">58</a></li> - -<li class="indx">Crystals, <a href="#Page_200">200</a> <i>et seq.</i>, <a href="#Page_237">237</a> <i>et seq.</i>, <a href="#Page_281">281</a> <i>et seq.</i></li> - -<li class="indx">Cytoplasm, <a href="#Page_161">161</a> <i>et seq.</i></li> - - -<li class="ifrst">Death, apparent, <a href="#Page_232">232</a>;</li> -<li class="isub1">senescence of, <a href="#Page_305">305</a> <i>et seq.</i>;</li> -<li class="isub1">cellular, <a href="#Page_321">321</a> <i>et seq.</i></li> - -<li class="indx">Decentralization, <a href="#Page_24">24</a></li> - -<li class="indx">Degeneration, <a href="#Page_326">326</a></li> - -<li class="indx">Destruction, functional, <a href="#Page_106">106</a>;</li> -<li class="isub1">organic, <a href="#Page_211">211</a>;</li> -<li class="isub1">of living matter, <a href="#Page_213">213</a></li> - -<li class="indx">Determinism, <a href="#Page_49">49</a></li> - -<li class="indx">Digestion, of plants and animals, <a href="#Page_152">152</a> <i>et seq.</i></li> - -<li class="indx">Direction, idea of, <a href="#Page_16">16</a></li> - -<li class="indx">Dominants, <a href="#Page_33">33</a>, <a href="#Page_39">39</a>, <a href="#Page_45">45</a></li> - -<li class="indx">Dyne, the, <a href="#Page_71">71</a></li> - - -<li class="ifrst">Effort, of force, <a href="#Page_71">71</a></li> - -<li class="indx">Electrolysis, <a href="#Page_272">272</a></li> - -<li class="indx">Energetics, <a href="#Page_39">39</a>, <a href="#Page_56">56</a>;</li> -<li class="isub1">laws of biological, <a href="#Page_105">105</a> <i>et seq.</i>, <a href="#Page_229">229</a>;</li> -<li class="isub1">alimentary, <a href="#Page_116">116</a> <i>et seq.</i></li> -<li class="indx"><span class="pagenum" id="Page_366">[Pg 366]</span></li> -<li class="indx">Energy, <a href="#Page_37">37</a>, Book ii., <i>passim</i>;</li> -<li class="isub1">origin of idea of, <a href="#Page_57">57</a>;</li> -<li class="isub1">theory of, <a href="#Page_62">62</a>;</li> -<li class="isub1">the only objective reality, <a href="#Page_64">64</a>-5;</li> -<li class="isub1">and kinetic conception, <a href="#Page_67">67</a>;</li> -<li class="isub1">mechanical, <a href="#Page_69">69</a>, <a href="#Page_73">73</a>;</li> -<li class="isub1">of contraction, <a href="#Page_75">75</a>;</li> -<li class="isub1">kinetic, <a href="#Page_76">76</a>, <a href="#Page_83">83</a>;</li> -<li class="isub1">potential, <a href="#Page_76">76</a>, <a href="#Page_83">83</a>;</li> -<li class="isub1">virtual, <a href="#Page_77">77</a>;</li> -<li class="isub1">of motion and position, <a href="#Page_79">79</a>;</li> -<li class="isub1">thermal, and its measurements, <a href="#Page_80">80</a>-2;</li> -<li class="isub1">chemical, and its measurements, <a href="#Page_81">81</a>-2;</li> -<li class="isub1">chemical and potential, <a href="#Page_83">83</a>;</li> -<li class="isub1">materialization of, <a href="#Page_84">84</a>;</li> -<li class="isub1">transformations of, <a href="#Page_85">85</a> <i>et seq.</i>;</li> -<li class="isub1">luminous, <a href="#Page_86">86</a> <i>et seq.</i>;</li> -<li class="isub1">conservation of, <a href="#Page_90">90</a> <i>et seq.</i>;</li> -<li class="isub1">capacity of conversion of, <a href="#Page_93">93</a>;</li> -<li class="isub1">in biology, <a href="#Page_97">97</a>;</li> -<li class="isub1">in living beings, <a href="#Page_99">99</a> <i>et seq.</i>;</li> -<li class="isub1">physical, <a href="#Page_99">99</a> <i>et seq.</i>;</li> -<li class="isub1">vital, <a href="#Page_99">99</a> <i>et seq.</i></li> - -<li class="indx">Ether, <a href="#Page_89">89</a></li> - -<li class="indx">Equivalence, law of, <a href="#Page_91">91</a></li> - -<li class="indx">Excitability, <a href="#Page_26">26</a>-7</li> - - -<li class="ifrst">Fatigue, of metals, <a href="#Page_264">264</a></li> - -<li class="indx">Ferments, butylic and butyric, <a href="#Page_193">193</a></li> - -<li class="indx">Filiation, <a href="#Page_250">250</a></li> - -<li class="indx">Finalism, <a href="#Page_43">43</a></li> - -<li class="indx">Food, a source of energy, <a href="#Page_118">118</a> <i>et seq.</i>;</li> -<li class="isub1">thermogenic and biothermogenic types of, <a href="#Page_131">131</a> <i>et seq.</i>;</li> -<li class="isub1">dynamogenic type of, <a href="#Page_143">143</a>;</li> -<li class="isub1">nitrogenous, <a href="#Page_143">143</a>;</li> -<li class="isub1">of animals and plants, <a href="#Page_153">153</a> <i>et seq.</i></li> - -<li class="indx">Force, directive, <a href="#Page_16">16</a> <i>et seq.</i>, <a href="#Page_32">32</a>, <a href="#Page_39">39</a>, <a href="#Page_48">48</a>;</li> -<li class="isub1">vital, <a href="#Page_45">45</a>;</li> -<li class="isub1">an anthromorphic notion, <a href="#Page_71">71</a>;</li> -<li class="isub1">and work, <a href="#Page_74">74</a>;</li> -<li class="isub1">measurement of, <a href="#Page_71">71</a>;</li> -<li class="isub1">plastic, <a href="#Page_143">143</a>;</li> -<li class="isub1">plastic and morphoplastic forces, <a href="#Page_208">208</a></li> - -<li class="indx">Form, specific, <a href="#Page_199">199</a> <i>et seq.</i>, <a href="#Page_281">281</a></li> - -<li class="indx">Fruits, acids of, <a href="#Page_136">136</a></li> - - -<li class="ifrst">Gemmules, <a href="#Page_167">167</a>, <a href="#Page_258">258</a></li> - -<li class="indx">Generation, spontaneous, <a href="#Page_249">249</a> <i>et seq.</i>, <a href="#Page_294">294</a> <i>et seq.</i></li> - -<li class="indx">Globulin, <a href="#Page_178">178</a></li> - -<li class="indx">Glycerine, crystals of, <a href="#Page_302">302</a></li> - -<li class="indx">Glycogen, <a href="#Page_108">108</a>, <a href="#Page_153">153</a> <i>et seq.</i></li> - -<li class="indx">Gramme, <a href="#Page_71">71</a></li> - - -<li class="ifrst">Heat, a mode of motion, <a href="#Page_61">61</a>;</li> -<li class="isub1">rôle of animal heat, <a href="#Page_122">122</a>;</li> -<li class="isub1">mechanical equivalent of, <a href="#Page_81">81</a>;</li> -<li class="isub1">an excretum, <a href="#Page_114">114</a>;</li> -<li class="isub1">a degraded form of energy, <a href="#Page_88">88</a>;</li> -<li class="isub1">converted into work, <a href="#Page_92">92</a></li> - -<li class="indx">Heterogeneity, <a href="#Page_38">38</a>, <a href="#Page_61">61</a></li> - -<li class="indx">Histones, <a href="#Page_179">179</a>, <a href="#Page_182">182</a> <i>et seq.</i></li> - -<li class="indx">Horse-power, <a href="#Page_75">75</a></li> - -<li class="indx">Hyaloplasm, <a href="#Page_161">161</a></li> - - -<li class="ifrst">Iatro-chemistry and mechanics, <a href="#Page_34">34</a>-5</li> - -<li class="indx">Idioblasts, <a href="#Page_167">167</a></li> - -<li class="indx">Infusoria, death of, <a href="#Page_337">337</a></li> - -<li class="indx">Instability, <a href="#Page_188">188</a> <i>et seq.</i></li> - -<li class="indx">Instinct, of life and death, <a href="#Page_345">345</a> <i>et seq.</i></li> - -<li class="indx">Intussusception, <a href="#Page_291">291</a></li> - -<li class="indx">Invariant, mass the first, <a href="#Page_63">63</a></li> - -<li class="indx">Irreversibility, of vital energies, <a href="#Page_104">104</a></li> - -<li class="indx">Irritability, <a href="#Page_27">27</a>, <a href="#Page_196">196</a> <i>et seq.</i></li> - -<li class="indx">Isodynamism, <a href="#Page_142">142</a></li> - -<li class="indx">Isomorphism, <a href="#Page_286">286</a></li> - - -<li class="ifrst">Ka, the, <a href="#Page_8">8</a></li> - -<li class="indx">Kilogrammetre, <a href="#Page_72">72</a>, <a href="#Page_75">75</a>;</li> -<li class="isub1">per second, <a href="#Page_75">75</a></li> - -<li class="indx">Kilowatt, <a href="#Page_76">76</a></li> - -<li class="indx">Kinetic theory, <a href="#Page_39">39</a>, <a href="#Page_62">62</a></li> - -<li class="indx">Knot, the vital, <a href="#Page_21">21</a></li> - - -<li class="ifrst">Leucines, <a href="#Page_183">183</a></li> - -<li class="indx">Leucites, <a href="#Page_163">163</a></li> - -<li class="indx">Life, defined, <a href="#Page_28">28</a>;</li> -<li class="isub1">latent, <a href="#Page_233">233</a>;</li> -<li class="isub1">physico-chemical theory of, <a href="#Page_36">36</a>;</li> -<li class="isub1">elementary, <a href="#Page_321">321</a></li> - -<li class="indx">Linin, <a href="#Page_163">163</a></li> - - -<li class="ifrst">Mass, and matter, <a href="#Page_63">63</a></li> - -<li class="indx">Materialism, <a href="#Page_34">34</a></li> - -<li class="indx">Matter, <a href="#Page_37">37</a>, <a href="#Page_60">60</a>, <a href="#Page_62">62</a>;</li> -<li class="isub1">and mass, <a href="#Page_63">63</a>;</li> -<li class="isub1">two kinds of, <a href="#Page_63">63</a>;</li> -<li class="isub1">life of, <a href="#Page_236">236</a> <i>et seq.</i>;</li> -<li class="isub1">brute and living, <a href="#Page_249">249</a> <i>et seq.</i>;</li> -<li class="isub1">organization and constitution of, <a href="#Page_255">255</a> <i>et seq.</i>;</li> -<li class="isub1">defined as extension, <a href="#Page_64">64</a>;</li> -<li class="isub1">conservation of, <a href="#Page_65">65</a> -<span class="pagenum" id="Page_367">[Pg 367]</span></li> -<li class="indx">“Memory,” of metals, etc., <a href="#Page_265">265</a></li> - -<li class="indx">Merotomy, <a href="#Page_47">47</a></li> - -<li class="indx">Metabolism, <a href="#Page_117">117</a></li> - -<li class="indx">Metazoa, evolution and death of, <a href="#Page_340">340</a> <i>et seq.</i></li> - -<li class="indx">Meteoric cosmozoa, <a href="#Page_252">252</a></li> - -<li class="indx">Micellar theory, <a href="#Page_166">166</a> <i>et seq.</i></li> - -<li class="indx">Microcosms, <a href="#Page_163">163</a></li> - -<li class="indx">Micro-organisms, culture of, <a href="#Page_297">297</a></li> - -<li class="indx">Mitomes, <a href="#Page_169">169</a></li> - -<li class="indx">Mobility of stars, <a href="#Page_260">260</a></li> - -<li class="indx">Modality, twofold, of soul, <a href="#Page_12">12</a></li> - -<li class="indx">Molecules, organic, <a href="#Page_254">254</a></li> - -<li class="indx">Monism, <a href="#Page_34">34</a>, Chap. iv. <i>passim</i>, <a href="#Page_63">63</a></li> - -<li class="indx">Montpellier, the school of, <a href="#Page_35">35</a></li> - -<li class="indx">Motion, cause of, <a href="#Page_71">71</a>;</li> -<li class="isub1">kinetic conception of molecular, <a href="#Page_263">263</a></li> - -<li class="indx">Morphogenesis, idea of, <a href="#Page_46">46</a></li> - -<li class="indx">Movements, internal of bodies, <a href="#Page_262">262</a>;</li> -<li class="isub1">Brownian, <a href="#Page_266">266</a> <i>et seq.</i></li> - -<li class="indx">Mutability, <a href="#Page_80">80</a>, <a href="#Page_188">188</a> <i>et seq.</i>;</li> -<li class="isub1">of living matter, <a href="#Page_259">259</a> <i>et seq.</i>;</li> -<li class="isub1">of brute bodies, <a href="#Page_259">259</a> <i>et seq.</i></li> - - -<li class="ifrst">Necrobiosis, <a href="#Page_326">326</a></li> - -<li class="indx">Neo-vitalism, <a href="#Page_15">15</a>, <a href="#Page_29">29</a>, <a href="#Page_32">32</a></li> - -<li class="indx">Neurility, <a href="#Page_27">27</a></li> - -<li class="indx">Nickel, steels, <a href="#Page_277">277</a></li> - -<li class="indx">Nisus <i>formativus</i>, <a href="#Page_46">46</a></li> - -<li class="indx">Nous, the, <a href="#Page_18">18</a>, <a href="#Page_239">239</a></li> - -<li class="indx">Nucleins, <a href="#Page_179">179</a>, <a href="#Page_180">180</a> <i>et seq.</i></li> - -<li class="indx">Nucleo-albuminoids, <a href="#Page_178">178</a>;</li> -<li class="isub1">-proteids, <a href="#Page_177">177</a> <i>et seq.</i></li> - -<li class="indx">Nucleus, <a href="#Page_163">163</a> <i>et seq.</i>;</li> -<li class="isub1">hexonic, <a href="#Page_186">186</a></li> - -<li class="indx">Nutrition, directed, <a href="#Page_205">205</a>, <a href="#Page_209">209</a> <i>et seq.</i>, <a href="#Page_227">227</a> <i>et seq.</i>, <a href="#Page_290">290</a> <i>et seq.</i></li> - - -<li class="ifrst">Organogenesis, <a href="#Page_282">282</a></li> - -<li class="indx">Organs, organization of, <a href="#Page_314">314</a>;</li> -<li class="isub1">death of, <a href="#Page_315">315</a>;</li> -<li class="isub1">perfect, <a href="#Page_319">319</a></li> - - -<li class="ifrst">Pangenes, <a href="#Page_167">167</a></li> - -<li class="indx">Panspermia, <a href="#Page_252">252</a></li> - -<li class="indx">Parameter, mass the mechanical, <a href="#Page_63">63</a></li> - -<li class="indx">Phenomena, vital, <a href="#Page_44">44</a>, <a href="#Page_51">51</a>, <a href="#Page_189">189</a>;</li> -<li class="isub1">modes of motion, <a href="#Page_61">61</a></li> - -<li class="indx">Photography, colour, <a href="#Page_277">277</a></li> - -<li class="indx">Physiology, general, <a href="#Page_56">56</a>;</li> -<li class="isub1">cellular, <a href="#Page_56">56</a></li> - -<li class="indx">Plants, and immortality, <a href="#Page_330">330</a></li> - -<li class="indx">Plasomes, <a href="#Page_167">167</a></li> - -<li class="indx">Plurivitalism, <a href="#Page_25">25</a></li> - -<li class="indx">Power, <a href="#Page_70">70</a>, <a href="#Page_75">75</a></li> - -<li class="indx">Principle, vital, <a href="#Page_15">15</a> <i>et seq.</i></li> - -<li class="indx">Properties, vital, <a href="#Page_25">25</a>, <a href="#Page_103">103</a></li> - -<li class="indx">Proteids, <a href="#Page_178">178</a></li> - -<li class="indx">Protoplasm, <a href="#Page_109">109</a> <i>et seq.</i>, <a href="#Page_175">175</a> <i>et seq.</i>, <a href="#Page_231">231</a> <i>et seq.</i>;</li> -<li class="isub1">life in crushed, <a href="#Page_257">257</a> <i>et seq.</i></li> - -<li class="indx">Protozoa, immortality of, <a href="#Page_352">352</a> <i>et seq.</i></li> - -<li class="indx">Psyche, <a href="#Page_239">239</a></li> - -<li class="indx">Pyrozoa, <a href="#Page_253">253</a></li> - - -<li class="ifrst">Regeneration, normal, <a href="#Page_205">205</a>;</li> -<li class="isub1">accidental, <a href="#Page_206">206</a></li> - -<li class="indx">Reparation, mechanism of, <a href="#Page_288">288</a></li> - -<li class="indx">Repose, functional, <a href="#Page_109">109</a>, <a href="#Page_217">217</a> <i>et seq.</i></li> - -<li class="indx">Reserve stuff, <a href="#Page_106">106</a> <i>et seq.</i>, <a href="#Page_212">212</a>, <a href="#Page_230">230</a> <i>et seq.</i></li> - -<li class="indx">Rachidian, soul, <a href="#Page_12">12</a></li> - - -<li class="ifrst">Senescence, <a href="#Page_305">305</a> <i>et seq.</i></li> - -<li class="indx">Sensibility, in brute bodies, <a href="#Page_244">244</a></li> - -<li class="indx">Solidarity, of anatomical elements, humoral and nervous, <a href="#Page_317">317</a></li> - -<li class="indx">Soul, the, <a href="#Page_7">7</a> <i>et seq.</i></li> - -<li class="indx">Space, <a href="#Page_69">69</a></li> - -<li class="indx">Specificity, vital, <a href="#Page_48">48</a></li> - -<li class="indx">Spireme, <a href="#Page_165">165</a></li> - -<li class="indx">Spongioplasm, <a href="#Page_162">162</a></li> - -<li class="indx">States, initial and final, <a href="#Page_128">128</a></li> - -<li class="indx">Swelling, <a href="#Page_167">167</a></li> - -<li class="indx">Synthesis, organizing, <a href="#Page_109">109</a></li> - - -<li class="ifrst">Tagmata, <a href="#Page_169">169</a>, <a href="#Page_175">175</a></li> - -<li class="indx">Teleology, <a href="#Page_43">43</a></li> - -<li class="indx">Tetanus, bacteria of, <a href="#Page_193">193</a></li> - -<li class="indx">Thermogenesis, <a href="#Page_140">140</a></li> - -<li class="indx">Time, <a href="#Page_69">69</a></li> - -<li class="indx">Tonus, muscular, <a href="#Page_119">119</a></li> - -<li class="indx">Trees, and immortality, <a href="#Page_330">330</a> <i>et seq.</i></li> - -<li class="indx">Tripod, vital, <a href="#Page_2">2</a>, <a href="#Page_314">314</a></li> - -<li class="indx">Turgescence, <a href="#Page_168">168</a></li> - - -<li class="ifrst">Universe, the, mechanical explanation of, <a href="#Page_60">60</a>;</li> -<li class="isub1">the end of the, <a href="#Page_95">95</a></li> - -<li class="indx">Unity, chemical, of living beings, <a href="#Page_173">173</a> <i>et seq.</i>, <a href="#Page_321">321</a>;</li> -<li class="isub1">morphological, <a href="#Page_321">321</a> -<span class="pagenum" id="Page_368">[Pg 368]</span></li> - -<li class="ifrst">Vacuoles, <a href="#Page_113">113</a></li> - -<li class="indx">Vibrion, septic, <a href="#Page_193">193</a></li> - -<li class="indx">Vis viva, <a href="#Page_73">73</a></li> - -<li class="indx">Vital properties, theory of, <a href="#Page_29">29</a> <i>et seq.</i></li> - -<li class="indx">Vitalism, <a href="#Page_6">6</a>, <a href="#Page_7">7</a>, Chap. iii. <i>passim</i>;</li> -<li class="isub1">physico-chemical, <a href="#Page_29">29</a></li> - -<li class="indx">Vitality, phenomena of, <a href="#Page_216">216</a></li> - -<li class="indx">Vortex, vital, <a href="#Page_105">105</a>, <a href="#Page_120">120</a>, <a href="#Page_229">229</a> <i>et seq.</i></li> - -<li class="indx">Vulcans, <a href="#Page_26">26</a>-7</li> - - -<li class="ifrst">Weight, energy of position, <a href="#Page_64">64</a>;</li> -<li class="isub1">conservation of, <a href="#Page_65">65</a>;</li> -<li class="isub1">movement under action of, <a href="#Page_271">271</a> <i>et seq.</i></li> - -<li class="indx">Work, <a href="#Page_70">70</a>, <a href="#Page_72">72</a>;</li> -<li class="isub1">and force, <a href="#Page_74">74</a>, <a href="#Page_77">77</a>;</li> -<li class="isub1">converted into heat, <a href="#Page_92">92</a>;</li> -<li class="isub1">physiological, <a href="#Page_103">103</a></li> - - -<li class="ifrst">Xanthic bases, <a href="#Page_180">180</a></li> - - -<li class="ifrst">Zones, metastable and labile, <a href="#Page_301">301</a></li> -</ul> - - - - -<p class="center spaced"><span class="fs2">THE WALTER SCOTT PUBLISHING COMPANY, LTD., FELLING-ON-TYNE.</span></p> - - -<div class="footnotes"><h2>FOOTNOTES:</h2> - -<div class="footnote"> - -<p><a id="Footnote_1" href="#FNanchor_1" class="label">[1]</a> In a -thesis presented in 1742 at Montpellier, Bordeu, then only twenty years -of age, made game of the tasks imposed by animists on the Soul, “which -has to moisten the lips when required;” or, “whose anger produces the -symptoms of certain diseases;” or again, “which is prevented by the -consequences of original sin from guiding and directing the body.”</p> -</div> - - -<div class="footnote"> - -<p><a id="Footnote_2" href="#FNanchor_2" class="label">[2]</a> Reinke, <i>Die Welt als That</i>; Berlin, 1899.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_3" href="#FNanchor_3" class="label">[3]</a> In an article on the experimental method recently published -in the <i>Dictionnaire de Physiologie</i>, M. Ch. Richet writes as -follows:—“We must therefore never cease to carry out comparative -experiments. I do not hesitate to say that this -comparison is the basis of the experimental method.” It is in -fact what was taught by Claude Bernard in maxim and by -example. It is no exaggeration to assert that nine-tenths of the -errors which take place in research work are imputable to some -breach of this method. When an investigator makes a mistake, -save in the case of material error, it is almost certainly due to the -fact that he has neglected to carry out one of the comparative -tests required in the problem before him. The following is -an instance which happened since the above pages were -written:—Several years ago a chemist announced the existence -in the blood serum of a ferment, lipase, capable of -saponifying fats—that is to say, of extracting from them the fatty -acid. From this he deduced many consequences relative to the -mechanism of fermentations. But on the other hand, it has -been since shown (April 1902) that this lipase of the serum -does not exist. How did the error arise? The author in -question had mixed normally obtained serum with oil, and he -had noted the acidification of the mixture; he assured himself -of the fact by adding carbonate of soda. He saw the alkalinity -of the mixture, serum + oil + carbonate of soda, diminish, and he -drew the conclusion that the acid came from the saponified oil. -He did not make the comparative test, serum + carbonate of -soda. If he had done so, he would have ascertained that it also -succeeded, and that therefore as the acid did not come from -the saponification of the oil, since there was none, its production -could not prove the existence of a lipase.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_4" href="#FNanchor_4" class="label">[4]</a> Le Dantec has objected to this conception of phenomena -common to different living beings. He insists that all -phenomena which take place in a given living being are -proper to him, and differ, however slightly, from those of -another individual. The objection is more specious than real.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_5" href="#FNanchor_5" class="label">[5]</a> Mayer’s claim to fame has been disputed. A Scotch physicist, -P. G. Tait, has investigated the history of the law of the conservation -of energy, which is the history of the idea of energy. -The conception has taken time to penetrate the human mind, -but its experimental proof is of recent date. P. G. Tait finds an -almost complete expression of the law of the conservation of -energy in Newton’s third law of motion—namely, “the law of the -equality of action and reaction,” or rather, in the second explanation -which Newton gave of that law. In fact, it was from -this law that Helmholtz deduced it in 1847. He showed that -the law of the equality of action and reaction, considered as a -law of nature, involved the impossibility of perpetual motion, -and the impossibility of perpetual motion is, in another form, the -conservation of energy.</p> - -<p>At a meeting of the Academy of Science, at Berlin, 28th -March 1878, Du Bois-Reymond violently attacked Tait’s contention. -The honour of having been the first to conceive of the -idea of energy and conservation was awarded to Leibniz. -Newton had no right to it, for he appealed to divine intervention -to set the planetary system on its path when disturbed by accumulated -perturbations. On the other hand, Colding claims to -have drawn his knowledge of the law of conservation from -d’Alembert’s principle. Whatever may be the theoretical -foundations of this law, we are here dealing with its experimental -proof. According to Tait, the proof can no more be -attributed to R. Mayer than to Seguin. The real modern -authors of the principle of the conservation of energy, who gave -an experimental proof of it, are Colding, of Copenhagen, and -Joule, of Manchester.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_6" href="#FNanchor_6" class="label">[6]</a> It must be added that the absolute rigour of this law has -been called in question in recent researches. It would only -have an approximate value.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_7" href="#FNanchor_7" class="label">[7]</a> The dyne is the force which applied to the unit of mass -produces a unit of acceleration.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_8" href="#FNanchor_8" class="label">[8]</a> These words spoil the statement, for time has nothing to -do with it.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_9" href="#FNanchor_9" class="label">[9]</a> We therefore notice that the measures of force and work -bring in mass, space, and time. The typical force, weight, is -given by w = mg. On the other hand, we have by the laws of -falling bodies <i>v</i> = <i>gt</i>; <i>s</i> = 1∕2<i>gt<sup>2</sup></i>; -whence <i>g</i> = 2<i>s</i>∕<i>t<sup>2</sup></i>; <i>w</i> = <i>m</i>(2<i>s</i>∕ <i>t<sup>2</sup></i>); or, if -F be the force, M the mass, L the space described, and T the -time, we have F = MLT<sup>-2</sup>, which expresses what are called the -dimensions of the force—that is to say, the magnitudes with their -degree, which enter into its expression. We may thus easily -obtain the dimensions of work:—</p> - -<p> -<i>Work</i> = <i>f</i> × <i>s</i> = <i>mv<sup>2</sup></i>∕2 = ML<sup>2</sup>T<sup>-2</sup>.<br /> -</p> - - -</div> - -<div class="footnote"> - -<p><a id="Footnote_10" href="#FNanchor_10" class="label">[10]</a> The reason is to be found in the large number of indeterminates -in the problem we have to solve. It will be sufficient -to enumerate them: the two substances which exist in the -anatomical element, protoplasm and reserve-stuff, to which -are attributed contrary roles; the two conditions attributable -to the protoplasm, of manifested or latent activity; the faculty -possessed by both of being prolonged for an indeterminate -period, and of encroaching each on its protagonist when its -existence is at stake. Here are more elements than are necessary -to explain the positive or negative results of all the -experiments in the world.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_11" href="#FNanchor_11" class="label">[11]</a> There is another reason why the rôle of mechanical energy, -compared with that of thermal energy, is reduced, in the partition -of afferent, alimentary energy—at least, in animals which have not -to do excessive work. The unit of heat, the Calorie, is equivalent -to 425 units of work—<i>i.e.</i>, to 425 kilogrammetres. In the animal -at rest, the number of kilogrammetres representing the different -quantities of work done is small, the number of corresponding -Calories is 425 times smaller. It becomes almost negligeable in -comparison with the considerable number of Calories dissipated -in the form of heat.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_12" href="#FNanchor_12" class="label">[12]</a> It is not certain, however, that all the precautions taken -have the desired result. You cannot entirely deprive meat of its -carbohydrates.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_13" href="#FNanchor_13" class="label">[13]</a> M. Le Dantec, of whose philosophical and rigorously -systematic mind I have the highest opinion, has laid down a -new conception of life, the essential basis of which is this very -distinction between elementary life and ordinary life; between -the life of the elements or of the beings formed from a single -cell, protophytes and protozoa, and the life of ordinary animals -and plants, which are multicellular complexes, and for that -reason called <i>metazoa</i> and <i>metaphytes</i>.</p> - -<p>Further, in the <i>elementary life</i> peculiar to monocellular -beings (protozoa and cellular elements), M. Le Dantec distinguishes -three manners of being:—The first condition, which -is elementary life manifested in all its perfection, cellular -health; the second condition is deteriorated elementary life, -<i>cellular disease</i>; and the third condition, which is <i>latent life</i>. -I should say at once that in so far as the fundamental distinction -of the phenomena of <i>elementary life</i> and those of the -general life of animals and ordinary plants, metazoa or metaphytes -is concerned, we find it neither justified nor useful. -And further, <i>manifested elementary life</i>, as M. Le Dantec -understands it, would only belong to a small number of -<i>elementary beings</i>—for the protozoa, starting with the infusoria, -are not among the number—and to a still smaller number of -<i>anatomical elements</i>, since among the vertebrates we recognize -as almost the only elements satisfying it, the ovule, and perhaps -the leucocyte. Physiologists, therefore, do not agree with -M. Le Dantec as to the utility of adding one condition more to -those we all admit—namely, manifested animal life and latent -life.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_14" href="#FNanchor_14" class="label">[14]</a> Amylolytic ferments change starch and glycogen (<i>amyloses</i>) -into sugar.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_15" href="#FNanchor_15" class="label">[15]</a> Proteolytic ferments change proteids into peptones and -proteoses.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_16" href="#FNanchor_16" class="label">[16]</a> The enzyme known as lipase splits the fat or oil in germinating -seeds into a fatty acid and glycerine.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_17" href="#FNanchor_17" class="label">[17]</a> These ideas are clearly brought to light in a series of -articles in the <i>Revue Philosophique</i>, published in 1879 under -the title of “La problème physiologique de la vie,” and endorsed -by A. Dastre in his commentary on the <i>Phénomènes communs -aux animaux et aux plantes</i>.</p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_18" href="#FNanchor_18" class="label">[18]</a> Bear-animalcules, Sloth-animalcules. An order of Arachnida.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_19" href="#FNanchor_19" class="label">[19]</a> Minute thread worms, known as paste-eels and vinegar-eels.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_20" href="#FNanchor_20" class="label">[20]</a> Genus of Infusoria. Colpodea cucullus is found in infusions -of hay.—<span class="smcap">Tr.</span></p> - -</div> - -<div class="footnote"> - -<p><a id="Footnote_21" href="#FNanchor_21" class="label">[21]</a> Lately destroyed in a storm. [Tr.]</p> - -</div> -</div> - -<div style='display:block; margin-top:4em'>*** END OF THE PROJECT GUTENBERG EBOOK LIFE AND DEATH ***</div> -<div style='text-align:left'> - -<div style='display:block; margin:1em 0'> -Updated editions will replace the previous one—the old editions will -be renamed. -</div> - -<div style='display:block; margin:1em 0'> -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the United -States without permission and without paying copyright -royalties. Special rules, set forth in the General Terms of Use part -of this license, apply to copying and distributing Project -Gutenberg™ electronic works to protect the PROJECT GUTENBERG™ -concept and trademark. Project Gutenberg is a registered trademark, -and may not be used if you charge for an eBook, except by following -the terms of the trademark license, including paying royalties for use -of the Project Gutenberg trademark. If you do not charge anything for -copies of this eBook, complying with the trademark license is very -easy. You may use this eBook for nearly any purpose such as creation -of derivative works, reports, performances and research. Project -Gutenberg eBooks may be modified and printed and given away--you may -do practically ANYTHING in the United States with eBooks not protected -by U.S. copyright law. Redistribution is subject to the trademark -license, especially commercial redistribution. -</div> - -<div style='margin:0.83em 0; font-size:1.1em; text-align:center'>START: FULL LICENSE<br /> -<span style='font-size:smaller'>THE FULL PROJECT GUTENBERG LICENSE<br /> -PLEASE READ THIS BEFORE YOU DISTRIBUTE OR USE THIS WORK</span> -</div> - -<div style='display:block; margin:1em 0'> -To protect the Project Gutenberg™ mission of promoting the free -distribution of electronic works, by using or distributing this work -(or any other work associated in any way with the phrase “Project -Gutenberg”), you agree to comply with all the terms of the Full -Project Gutenberg™ License available with this file or online at -www.gutenberg.org/license. -</div> - -<div style='display:block; font-size:1.1em; margin:1em 0; font-weight:bold'> -Section 1. General Terms of Use and Redistributing Project Gutenberg™ electronic works -</div> - -<div style='display:block; margin:1em 0'> -1.A. By reading or using any part of this Project Gutenberg™ -electronic work, you indicate that you have read, understand, agree to -and accept all the terms of this license and intellectual property -(trademark/copyright) agreement. If you do not agree to abide by all -the terms of this agreement, you must cease using and return or -destroy all copies of Project Gutenberg™ electronic works in your -possession. If you paid a fee for obtaining a copy of or access to a -Project Gutenberg™ electronic work and you do not agree to be bound -by the terms of this agreement, you may obtain a refund from the person -or entity to whom you paid the fee as set forth in paragraph 1.E.8. -</div> - -<div style='display:block; margin:1em 0'> -1.B. “Project Gutenberg” is a registered trademark. It may only be -used on or associated in any way with an electronic work by people who -agree to be bound by the terms of this agreement. There are a few -things that you can do with most Project Gutenberg™ electronic works -even without complying with the full terms of this agreement. See -paragraph 1.C below. There are a lot of things you can do with Project -Gutenberg™ electronic works if you follow the terms of this -agreement and help preserve free future access to Project Gutenberg™ -electronic works. See paragraph 1.E below. -</div> - -<div style='display:block; margin:1em 0'> -1.C. The Project Gutenberg Literary Archive Foundation (“the -Foundation” or PGLAF), owns a compilation copyright in the collection -of Project Gutenberg™ electronic works. Nearly all the individual -works in the collection are in the public domain in the United -States. If an individual work is unprotected by copyright law in the -United States and you are located in the United States, we do not -claim a right to prevent you from copying, distributing, performing, -displaying or creating derivative works based on the work as long as -all references to Project Gutenberg are removed. Of course, we hope -that you will support the Project Gutenberg™ mission of promoting -free access to electronic works by freely sharing Project Gutenberg™ -works in compliance with the terms of this agreement for keeping the -Project Gutenberg™ name associated with the work. You can easily -comply with the terms of this agreement by keeping this work in the -same format with its attached full Project Gutenberg™ License when -you share it without charge with others. -</div> - -<div style='display:block; margin:1em 0'> -1.D. The copyright laws of the place where you are located also govern -what you can do with this work. Copyright laws in most countries are -in a constant state of change. If you are outside the United States, -check the laws of your country in addition to the terms of this -agreement before downloading, copying, displaying, performing, -distributing or creating derivative works based on this work or any -other Project Gutenberg™ work. The Foundation makes no -representations concerning the copyright status of any work in any -country other than the United States. -</div> - -<div style='display:block; margin:1em 0'> -1.E. Unless you have removed all references to Project Gutenberg: -</div> - -<div style='display:block; margin:1em 0'> -1.E.1. The following sentence, with active links to, or other -immediate access to, the full Project Gutenberg™ License must appear -prominently whenever any copy of a Project Gutenberg™ work (any work -on which the phrase “Project Gutenberg” appears, or with which the -phrase “Project Gutenberg” is associated) is accessed, displayed, -performed, viewed, copied or distributed: -</div> - -<blockquote> - <div style='display:block; margin:1em 0'> - This eBook is for the use of anyone anywhere in the United States and most - other parts of the world at no cost and with almost no restrictions - whatsoever. You may copy it, give it away or re-use it under the terms - of the Project Gutenberg License included with this eBook or online - at <a href="https://www.gutenberg.org">www.gutenberg.org</a>. If you - are not located in the United States, you will have to check the laws - of the country where you are located before using this eBook. - </div> -</blockquote> - -<div style='display:block; margin:1em 0'> -1.E.2. If an individual Project Gutenberg™ electronic work is -derived from texts not protected by U.S. copyright law (does not -contain a notice indicating that it is posted with permission of the -copyright holder), the work can be copied and distributed to anyone in -the United States without paying any fees or charges. If you are -redistributing or providing access to a work with the phrase “Project -Gutenberg” associated with or appearing on the work, you must comply -either with the requirements of paragraphs 1.E.1 through 1.E.7 or -obtain permission for the use of the work and the Project Gutenberg™ -trademark as set forth in paragraphs 1.E.8 or 1.E.9. -</div> - -<div style='display:block; margin:1em 0'> -1.E.3. If an individual Project Gutenberg™ electronic work is posted -with the permission of the copyright holder, your use and distribution -must comply with both paragraphs 1.E.1 through 1.E.7 and any -additional terms imposed by the copyright holder. Additional terms -will be linked to the Project Gutenberg™ License for all works -posted with the permission of the copyright holder found at the -beginning of this work. -</div> - -<div style='display:block; margin:1em 0'> -1.E.4. Do not unlink or detach or remove the full Project Gutenberg™ -License terms from this work, or any files containing a part of this -work or any other work associated with Project Gutenberg™. -</div> - -<div style='display:block; margin:1em 0'> -1.E.5. Do not copy, display, perform, distribute or redistribute this -electronic work, or any part of this electronic work, without -prominently displaying the sentence set forth in paragraph 1.E.1 with -active links or immediate access to the full terms of the Project -Gutenberg™ License. -</div> - -<div style='display:block; margin:1em 0'> -1.E.6. You may convert to and distribute this work in any binary, -compressed, marked up, nonproprietary or proprietary form, including -any word processing or hypertext form. However, if you provide access -to or distribute copies of a Project Gutenberg™ work in a format -other than “Plain Vanilla ASCII” or other format used in the official -version posted on the official Project Gutenberg™ website -(www.gutenberg.org), you must, at no additional cost, fee or expense -to the user, provide a copy, a means of exporting a copy, or a means -of obtaining a copy upon request, of the work in its original “Plain -Vanilla ASCII” or other form. Any alternate format must include the -full Project Gutenberg™ License as specified in paragraph 1.E.1. -</div> - -<div style='display:block; margin:1em 0'> -1.E.7. Do not charge a fee for access to, viewing, displaying, -performing, copying or distributing any Project Gutenberg™ works -unless you comply with paragraph 1.E.8 or 1.E.9. -</div> - -<div style='display:block; margin:1em 0'> -1.E.8. You may charge a reasonable fee for copies of or providing -access to or distributing Project Gutenberg™ electronic works -provided that: -</div> - -<div style='margin-left:0.7em;'> - <div style='text-indent:-0.7em'> - • You pay a royalty fee of 20% of the gross profits you derive from - the use of Project Gutenberg™ works calculated using the method - you already use to calculate your applicable taxes. The fee is owed - to the owner of the Project Gutenberg™ trademark, but he has - agreed to donate royalties under this paragraph to the Project - Gutenberg Literary Archive Foundation. Royalty payments must be paid - within 60 days following each date on which you prepare (or are - legally required to prepare) your periodic tax returns. Royalty - payments should be clearly marked as such and sent to the Project - Gutenberg Literary Archive Foundation at the address specified in - Section 4, “Information about donations to the Project Gutenberg - Literary Archive Foundation.” - </div> - - <div style='text-indent:-0.7em'> - • You provide a full refund of any money paid by a user who notifies - you in writing (or by e-mail) within 30 days of receipt that s/he - does not agree to the terms of the full Project Gutenberg™ - License. You must require such a user to return or destroy all - copies of the works possessed in a physical medium and discontinue - all use of and all access to other copies of Project Gutenberg™ - works. - </div> - - <div style='text-indent:-0.7em'> - • You provide, in accordance with paragraph 1.F.3, a full refund of - any money paid for a work or a replacement copy, if a defect in the - electronic work is discovered and reported to you within 90 days of - receipt of the work. - </div> - - <div style='text-indent:-0.7em'> - • You comply with all other terms of this agreement for free - distribution of Project Gutenberg™ works. - </div> -</div> - -<div style='display:block; margin:1em 0'> -1.E.9. If you wish to charge a fee or distribute a Project -Gutenberg™ electronic work or group of works on different terms than -are set forth in this agreement, you must obtain permission in writing -from the Project Gutenberg Literary Archive Foundation, the manager of -the Project Gutenberg™ trademark. Contact the Foundation as set -forth in Section 3 below. -</div> - -<div style='display:block; margin:1em 0'> -1.F. -</div> - -<div style='display:block; margin:1em 0'> -1.F.1. Project Gutenberg volunteers and employees expend considerable -effort to identify, do copyright research on, transcribe and proofread -works not protected by U.S. copyright law in creating the Project -Gutenberg™ collection. Despite these efforts, Project Gutenberg™ -electronic works, and the medium on which they may be stored, may -contain “Defects,” such as, but not limited to, incomplete, inaccurate -or corrupt data, transcription errors, a copyright or other -intellectual property infringement, a defective or damaged disk or -other medium, a computer virus, or computer codes that damage or -cannot be read by your equipment. -</div> - -<div style='display:block; margin:1em 0'> -1.F.2. LIMITED WARRANTY, DISCLAIMER OF DAMAGES - Except for the “Right -of Replacement or Refund” described in paragraph 1.F.3, the Project -Gutenberg Literary Archive Foundation, the owner of the Project -Gutenberg™ trademark, and any other party distributing a Project -Gutenberg™ electronic work under this agreement, disclaim all -liability to you for damages, costs and expenses, including legal -fees. YOU AGREE THAT YOU HAVE NO REMEDIES FOR NEGLIGENCE, STRICT -LIABILITY, BREACH OF WARRANTY OR BREACH OF CONTRACT EXCEPT THOSE -PROVIDED IN PARAGRAPH 1.F.3. YOU AGREE THAT THE FOUNDATION, THE -TRADEMARK OWNER, AND ANY DISTRIBUTOR UNDER THIS AGREEMENT WILL NOT BE -LIABLE TO YOU FOR ACTUAL, DIRECT, INDIRECT, CONSEQUENTIAL, PUNITIVE OR -INCIDENTAL DAMAGES EVEN IF YOU GIVE NOTICE OF THE POSSIBILITY OF SUCH -DAMAGE. -</div> - -<div style='display:block; margin:1em 0'> -1.F.3. LIMITED RIGHT OF REPLACEMENT OR REFUND - If you discover a -defect in this electronic work within 90 days of receiving it, you can -receive a refund of the money (if any) you paid for it by sending a -written explanation to the person you received the work from. If you -received the work on a physical medium, you must return the medium -with your written explanation. The person or entity that provided you -with the defective work may elect to provide a replacement copy in -lieu of a refund. If you received the work electronically, the person -or entity providing it to you may choose to give you a second -opportunity to receive the work electronically in lieu of a refund. If -the second copy is also defective, you may demand a refund in writing -without further opportunities to fix the problem. -</div> - -<div style='display:block; margin:1em 0'> -1.F.4. Except for the limited right of replacement or refund set forth -in paragraph 1.F.3, this work is provided to you ‘AS-IS’, WITH NO -OTHER WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT -LIMITED TO WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PURPOSE. -</div> - -<div style='display:block; margin:1em 0'> -1.F.5. Some states do not allow disclaimers of certain implied -warranties or the exclusion or limitation of certain types of -damages. If any disclaimer or limitation set forth in this agreement -violates the law of the state applicable to this agreement, the -agreement shall be interpreted to make the maximum disclaimer or -limitation permitted by the applicable state law. The invalidity or -unenforceability of any provision of this agreement shall not void the -remaining provisions. -</div> - -<div style='display:block; margin:1em 0'> -1.F.6. INDEMNITY - You agree to indemnify and hold the Foundation, the -trademark owner, any agent or employee of the Foundation, anyone -providing copies of Project Gutenberg™ electronic works in -accordance with this agreement, and any volunteers associated with the -production, promotion and distribution of Project Gutenberg™ -electronic works, harmless from all liability, costs and expenses, -including legal fees, that arise directly or indirectly from any of -the following which you do or cause to occur: (a) distribution of this -or any Project Gutenberg™ work, (b) alteration, modification, or -additions or deletions to any Project Gutenberg™ work, and (c) any -Defect you cause. -</div> - -<div style='display:block; font-size:1.1em; margin:1em 0; font-weight:bold'> -Section 2. Information about the Mission of Project Gutenberg™ -</div> - -<div style='display:block; margin:1em 0'> -Project Gutenberg™ is synonymous with the free distribution of -electronic works in formats readable by the widest variety of -computers including obsolete, old, middle-aged and new computers. It -exists because of the efforts of hundreds of volunteers and donations -from people in all walks of life. -</div> - -<div style='display:block; margin:1em 0'> -Volunteers and financial support to provide volunteers with the -assistance they need are critical to reaching Project Gutenberg™’s -goals and ensuring that the Project Gutenberg™ collection will -remain freely available for generations to come. In 2001, the Project -Gutenberg Literary Archive Foundation was created to provide a secure -and permanent future for Project Gutenberg™ and future -generations. To learn more about the Project Gutenberg Literary -Archive Foundation and how your efforts and donations can help, see -Sections 3 and 4 and the Foundation information page at www.gutenberg.org. -</div> - -<div style='display:block; font-size:1.1em; margin:1em 0; font-weight:bold'> -Section 3. Information about the Project Gutenberg Literary Archive Foundation -</div> - -<div style='display:block; margin:1em 0'> -The Project Gutenberg Literary Archive Foundation is a non-profit -501(c)(3) educational corporation organized under the laws of the -state of Mississippi and granted tax exempt status by the Internal -Revenue Service. The Foundation’s EIN or federal tax identification -number is 64-6221541. Contributions to the Project Gutenberg Literary -Archive Foundation are tax deductible to the full extent permitted by -U.S. federal laws and your state’s laws. -</div> - -<div style='display:block; margin:1em 0'> -The Foundation’s business office is located at 809 North 1500 West, -Salt Lake City, UT 84116, (801) 596-1887. Email contact links and up -to date contact information can be found at the Foundation’s website -and official page at www.gutenberg.org/contact -</div> - -<div style='display:block; font-size:1.1em; margin:1em 0; font-weight:bold'> -Section 4. Information about Donations to the Project Gutenberg Literary Archive Foundation -</div> - -<div style='display:block; margin:1em 0'> -Project Gutenberg™ depends upon and cannot survive without widespread -public support and donations to carry out its mission of -increasing the number of public domain and licensed works that can be -freely distributed in machine-readable form accessible by the widest -array of equipment including outdated equipment. Many small donations -($1 to $5,000) are particularly important to maintaining tax exempt -status with the IRS. -</div> - -<div style='display:block; margin:1em 0'> -The Foundation is committed to complying with the laws regulating -charities and charitable donations in all 50 states of the United -States. Compliance requirements are not uniform and it takes a -considerable effort, much paperwork and many fees to meet and keep up -with these requirements. We do not solicit donations in locations -where we have not received written confirmation of compliance. To SEND -DONATIONS or determine the status of compliance for any particular state -visit <a href="https://www.gutenberg.org/donate/">www.gutenberg.org/donate</a>. -</div> - -<div style='display:block; margin:1em 0'> -While we cannot and do not solicit contributions from states where we -have not met the solicitation requirements, we know of no prohibition -against accepting unsolicited donations from donors in such states who -approach us with offers to donate. -</div> - -<div style='display:block; margin:1em 0'> -International donations are gratefully accepted, but we cannot make -any statements concerning tax treatment of donations received from -outside the United States. U.S. laws alone swamp our small staff. -</div> - -<div style='display:block; margin:1em 0'> -Please check the Project Gutenberg web pages for current donation -methods and addresses. Donations are accepted in a number of other -ways including checks, online payments and credit card donations. To -donate, please visit: www.gutenberg.org/donate -</div> - -<div style='display:block; font-size:1.1em; margin:1em 0; font-weight:bold'> -Section 5. General Information About Project Gutenberg™ electronic works -</div> - -<div style='display:block; margin:1em 0'> -Professor Michael S. Hart was the originator of the Project -Gutenberg™ concept of a library of electronic works that could be -freely shared with anyone. For forty years, he produced and -distributed Project Gutenberg™ eBooks with only a loose network of -volunteer support. -</div> - -<div style='display:block; margin:1em 0'> -Project Gutenberg™ eBooks are often created from several printed -editions, all of which are confirmed as not protected by copyright in -the U.S. unless a copyright notice is included. Thus, we do not -necessarily keep eBooks in compliance with any particular paper -edition. -</div> - -<div style='display:block; margin:1em 0'> -Most people start at our website which has the main PG search -facility: <a href="https://www.gutenberg.org">www.gutenberg.org</a>. -</div> - -<div style='display:block; margin:1em 0'> -This website includes information about Project Gutenberg™, -including how to make donations to the Project Gutenberg Literary -Archive Foundation, how to help produce our new eBooks, and how to -subscribe to our email newsletter to hear about new eBooks. -</div> - -</div> - -</body> -</html> |