CHAPTER VII.
MAN. THE INSTINCT OF LIFE AND THE INSTINCT OF DEATH.
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.
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.
§ 1. DISEASE.
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 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.”
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 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.
§ 2. OLD AGE.
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. La Bruyère expresses it in an apothegm, “We want to grow old, and we fear old age.” One would like longevity without old age.
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.
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.
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 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.
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.
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.
On the other hand, if we ask ourselves what is the 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 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.
§ 3. DISHARMONIES IN HUMAN NATURE.
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.
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 remote animal ancestors, atrophied in the course of ages in consequence of modifications that have taken place in the external medium.
These rudimentary organs are not only useless; they are often positively harmful.
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.
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.
The family instinct is subject to the same aberrations. Man limits the number of his children. The 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.
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.
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.
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 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 _mens sana in corpore sano_ 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.
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 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 _Pithecanthropus erectus_. 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: _natura facit saltus_. 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.
§ 4. THE INSTINCT OF LIFE AND THE INSTINCT OF DEATH.
The greatest discrepancy of this kind is the knowledge of inevitable death without the instinct which makes it longed for.
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.
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.
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 most like the dead dies with most regret.” Man knows that he is not getting his full measure.
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.
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 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 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 _Panathenaïcus_ at 94; Gorgias died in the full possession of his intellect at 107.
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. _Contra vim mortis non est medicamen in hortis_, 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.
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 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....
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:—
“_I should like to leave life at this age, just as one leaves a banquet, thanking the host, and departing._”
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 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?
INDEX OF AUTHORS.
Altmann, 258
Anaxagoras, 34
Aquinas, St. Thomas, 3, 19, 248
Aristotle, 3, 15, 18, 143, 146, 307
Armstrong, 295
Atwater, 137
Bacon, vi., 35, 346
Baker, 233
Balbiani, 161, 165, 191, 206-7, 257
Bang, d’Yvor, 179
Barthez, 3, 19, 24
Beclard, 121
Becquerel, 278
Beijerinck, 193
Benoit, 271
Bernard, Claude, vi., 17, 27, 29, 32, 48, 50-4, 107, 109, 112, 119, 148, 150-1, 171, 190-2, 194, 197, 204, 210, 214-218, 220 _et seq._, 310, 318
Bernoulli, John, 35, 73
Bert, Paul, 194
Berthelot, 91, 98, 128-130, 152, 204, 296
Berthollet, 82
Berzelius, 117
Bichat, 3, 6, 20, 22, 27-30, 35, 55, 158, 170, 198, 308
Blumenbach, 46
Boë, Sylvius Le, 35-6
Boerhaave, 35, 147, 245
Bohr, 29-30
Bokorny, 324
Boltzmann, 265
Bonnet, 23, 49
Bordeu, 3, 10, 19, 22, 24, 312
Borelli, 35
Boscovitch, 37, 248
Bose, 264
Bossuet, 11
Bouasse, 73, 264-5
Boullier, 12
Bourdeau, 237, 242
Boussingault, 149
Brandt, 257
Bravais, 282
Brillouin, 264, 273
Brown, 266 _et seq._
Brücke, 44
Büchner, 325
Buffon, 46, 254, 357
Bunge, von, 3, 14
Burdon, Sanderson, 176
Busquet, 175
Bütschli, 161-2, 175
Cabanis, 245, 246
Cailletet, 272
Calkins, 327, 338
Calvert, 271
Candolle, 20
Cardan, 261
Carnot, 72-3, 89, 92 _et seq._, 101, 114, 121
Charpy, 237, 271
Chauffard, 3, 10, 11, 294
Chauveau, 75, 103, 108, 123, 130, 145, 213
Chevreul, 32
Chossat, 152
Cicero, 347, 359
Clausius, 67, 88
Cohn, 191, 252
Cohnheim, 341
Colding, 58 _note_, 90
Colin, 52
Comte, 189-190, 310
Confucius, 309
Coulomb, 76, 264, 273
Crookes, 295, 302
Cuvier, 3, 6, 27-8, 105, 120, 152, 190, 198, 308, 310, 319
D’Alembert, 20, 59 _note_, 90, 92
Dantec, Le, 48, 52, 55 _note_, 110, 148, 173, 198, 201, 203, 213, 216, 220, 223 _et seq._, 231, 246, 261, 285, 296, 340
D’Arsonval, 126
Darwin, 3, 46, 167, 258, 354
Dastre, A., 192, 198 _note_
Davy, Sir Humphry, 61, 80
Delafosse, 282
Delage, 208
Demange, 349
Democritus, 34, 146
Descartes, 3, 9, 35, 37, 40, 73, 91, 98
Despretz, 126
Diderot, 245, 246
Drechsel, 183
Dressel, 20
Dubois-Reymond, 44, 58 _note_, 253
Duclaux, 119, 137, 184, 324
Dufour, 297
Duguet, 264
Duhem, 62, 264, 265
Dulong, 126
Dumas, 115, 149, 151-2
Epicurus, 35, 146
Ehrlich, 176
Errera, 52, 193-4, 237, 153, 295, 302 _et seq._
Euclid, v.
Faye, 260
Feuchterslehen, 358
Flemming, 161
Flourens, 20-1, 152, 208, 306, 358
Fouillée, 242
Fromann, 161
Fuerth, 183
Galen, 25, 55, 143
Galeotti, 180
Galileo, 73, 91, 98, 197, 241, 260
Gardair, 19, 248
Gautier, A., 3, 32, 36, 39, 176, 233, 324
Gernez, 237, 288, 295 _et seq._
Glisson, 27
Goethe, 170, 312
Gouy, 266, 268
Grimaud, 19
Gruber, 165, 206, 257
Guignard, 161
Guillaume, 237, 262, 264, 271, 277
Guillemin, 237
Guldberg, 83
Harbermann, 183
Haeckel, 3, 46, 164, 167, 246, 251
Hales, 43
Haller, 27
Hamilton, Sir W. Rowan, 67
Hammarsten, 180
Hartmann, 276, 346
Harvey, 43, 160
Haüy, 282
Hegel, 170, 331
Heidenhain, 3, 29, 30-1
Heitzmann, 161
Helmholtz, 44, 56, 58, 67, 90, 97, 99, 252
Helmont, van, 3, 21, 26, 33, 146, 250
Henninger, 302
Heraclitus, 34
Hertwig, 167
Hertz, 88
Hess, 91, 98
Hippocrates, 146
Hirn, 126
His, 46
Hlasitwetz, 183
Holbach, d’, 354
Hoogewerf, 303
Hopkinson, 271
Humboldt, W. von, 354
Ingenhousz, 115
Izolet, 247
Joule, 53 _note_, 90-1, 93, 133 _et seq._, 143, 152
Kant, 312, 319
Kaup, 213
Kaufmann, 126
Kelvin, Lord, 63, 67, 90, 92, 251-2, 264; and the idea of energy, 66
Kepler, 29, 241
Klemm, 323
Koelliker, 160
Kossel, 174, 179, 130-1, 136 _et seq._
Kuhne, 45
Kuhm, 216
Kuliabko, 23, 311
Kunstler, 157, 161-2, 175
Kuppfer, 161
Lammettrie, 147
Lamarck, 46
Lapparent, 284
Lapicque, 140, 145
Langley, 216
Laplace, 43, 63, 126, 260
Laulanié, 103
Laurie, 271
La Rochefoucauld, 356
Lavoisier, 3, 28, 30, 36, 43, 65, 117, 121, 126, 128, 143, 176, 296
Lea, 216
Le Châtelier, 85, 92
Lechatelier, H. and A., 271
Lecocq de Boisbaudran, 295
Leeuwenhoek, 232
Lefèvre, 126
Legallois, 21
Leydig, 161-2
Liebermeister, 136
Liebig, 26, 53 _note_, 117
Lilienfeld, 179, 247
Locke, 23
Lodge, 271
Loeb, 43, 167, 327, 341
Loew, 324
Loisel, 339, 341
Lorry, 21
Longet, 52
Lowitz, 297
Loye, 192
Ludwig, 44, 215
Mach, 41, 62
Magendie, 43, 143
Magy, 37
Malgaigne, 153
Mallard, 284
Marinesco, 231, 328
Markel, 349
Maspero, 3, 234
Matthiesson, 271
Maupas, 337
Maxwell, 88
Mayer, R., 56, 58, 89, 90, 97, 99, 101
Mering, von, 133, 136
Metchnikoff, 327 _et seq._
Miescher, 174, 179
Milne-Edwards, 152, 195
Minot, 341
Miura, 137
Mori, 145
Müller, 20, 27, 341
Murato, 45
Naegeli, 168
Needham, 46
Newton, 58 _note_, 70, 90-1, 93
Noorden, van, 129, 137, 140, 210
Nussbaum, 165, 206, 215, 217
Obermeyer, 271
Osmond, 237, 271
Ostwald, 41, 62, 67, 85, 104, 237, 258, 289, 295 _et seq._
Paracelsus, 26, 146, 312
Pascal, 74, 161
Pasteur, 53, 191, 222 _et seq._, 237, 250, 288, 346
Payen, 151
Persoz, 152
Petit, 180
Pettenkofer, 210
Pfeffer, 175, 193
Pflüger, 12, 56, 135, 144, 176, 210, 213
Philpotts, 46
Pictet, 233
Pitcairn, 35
Plato, 35, 307
Plosz, 180
Poincaré, 62
Poisson, 63
Preyer, 192, 252 _et seq._
Priestley, 115
Ptolemy, v.
Pythagoras, 18
Rauber, 237, 288
Raulin, 191
Regnault, 117
Reinke, 3, 32
Renan, 240
Ribbert, 208
Ribot, 247
Riche, 271
Richet, 50, 126, 140
Richter, 252
Rindfleisch, 4
Roberts-Austen, 237, 271-2
Robin, 62, 177
Rosenthal, 126
Rouvier, 160
Roux, 46, 165
Rubner, 129, 130, 140 _et seq._, 210
Rumford, 80
Sabatier, 242
Sachs, 161, 194
Salles-Guyon, 252
Sanderson, Burdon, 176
Scaliger, 241
Schleiden, 159
Schopenhauer, 346
Schwartz, 162
Schultze, 160, 326
Schultzenberger, 174, 162 _et seq._
Secchi, 88
Seguin, 58 _note_, 90
Senebier, 115
Siven, 145
Spallanzani, 43, 233
Spencer, Herbert, 46, 247, 354, 358
Spring, 272
Stahl, 3, 9, 12, 35, 146
Stammreich, 137
Stead, 237
Stohmann, 129, 130, 140
Strassburger, 161, 350
Swann, 159
Swift, 262
Tait, 53 _note_, 66
Tammann, 237, 253, 295 _et seq._
Thales, 34
Thomson, Sir J. J., 279
Tissot, 12
Tomlinson, 264
Trembley, 22, 206
Tsuboï, 145
Tylor, 8
Verworn, 206, 252, 257
Violette, 295
Virchow, 318, 326
Voit, 119, 133 _et seq._, 210
Vries, de, 46, 258, 355
Vulpian, 24
Waage, 83
Waller, 47, 206
Wallerant, 282-3
Warburg, 264
Watt, 76
Weismann, 46, 167, 336, 343
Wertheim, 264
Whitman, 46
Widersheim, 351
Wiedermann, 264
Wiesner, 167
Willis, 36, 147
Winternitz, 126
Yung, 233
Zuntz, 133, 136, 210
INDEX OF SUBJECTS.
Activity, functional and vital, 106 _et seq._, 217 _et seq._
Aerobia, 193
Age, old, Book v.
Albumin, 178
Albuminoids, 178
Alcohol, 136
Alimentation, 116 _et seq._
Alloys, structure of, 273
Anærobia, 193
Animism, 6, 7, Chap. ii., _passim_
Annealing, 275
Apposition, 291
Archeus, the, 25, 26, 33
Arginin, 187
Assimilation, law of functional, 110, 213
Atomicities, satisfied, 185
Atrophy, 326
Attraction, energy of position, 64
Balance, sheet, nutritive, 118
Beliefs, primitive, 239
Bioblasts, 253
Biophors, 167
Blas, the, 25, 33
Blood, lavage of, 192
Brain, and death, 315
Butylic ferments, 193
Butyric ferments, 193
Calorie, 125 _note_
Calorimeter, ice, 126; bomb, 128
Caprice, of Nature, 45
Cause, final, 45
Cells, 48, 147; somatic and sexual, 343
Cellular theory, 158 _et seq._
Centrosome, 163
Chromosome, 165
Cicatrization, 287
Complex, homogeneity of the, 245
Conductibility, 26
Consciousness, in brute bodies, 244 _et seq._
Continuity, principle of, 242, 247
Contractility, 26
Contraction, energy of static and dynamic, 75
Conservation, of energy, 58; of force, 58
Crystals, 200 _et seq._, 237 _et seq._, 281 _et seq._
Cytoplasm, 161 _et seq._
Death, apparent, 232; senescence of, 305 _et seq._; cellular, 321 _et seq._
Decentralization, 24
Degeneration, 326
Destruction, functional, 106; organic, 211; of living matter, 213
Determinism, 49
Digestion, of plants and animals, 152 _et seq._
Direction, idea of, 16
Dominants, 33, 39, 45
Dyne, the, 71
Effort, of force, 71
Electrolysis, 272
Energetics, 39, 56; laws of biological, 105 _et seq._, 229; alimentary, 116 _et seq._
Energy, 37, Book ii., _passim_; origin of idea of, 57; theory of, 62; the only objective reality, 64-5; and kinetic conception, 67; mechanical, 69, 73; of contraction, 75; kinetic, 76, 83; potential, 76, 83; virtual, 77; of motion and position, 79; thermal, and its measurements, 80-2; chemical, and its measurements, 81-2; chemical and potential, 83; materialization of, 84; transformations of, 85 _et seq._; luminous, 86 _et seq._; conservation of, 90 _et seq._; capacity of conversion of, 93; in biology, 97; in living beings, 99 _et seq._; physical, 99 _et seq._; vital, 99 _et seq._
Ether, 89
Equivalence, law of, 91
Excitability, 26-7
Fatigue, of metals, 264
Ferments, butylic and butyric, 193
Filiation, 250
Finalism, 43
Food, a source of energy, 118 _et seq._; thermogenic and biothermogenic types of, 131 _et seq._; dynamogenic type of, 143; nitrogenous, 143; of animals and plants, 153 _et seq._
Force, directive, 16 _et seq._, 32, 39, 48; vital, 45; an anthromorphic notion, 71; and work, 74; measurement of, 71; plastic, 143; plastic and morphoplastic forces, 208
Form, specific, 199 _et seq._, 281
Fruits, acids of, 136
Gemmules, 167, 258
Generation, spontaneous, 249 _et seq._, 294 _et seq._
Globulin, 178
Glycerine, crystals of, 302
Glycogen, 108, 153 _et seq._
Gramme, 71
Heat, a mode of motion, 61; rôle of animal heat, 122; mechanical equivalent of, 81; an excretum, 114; a degraded form of energy, 88; converted into work, 92
Heterogeneity, 38, 61
Histones, 179, 182 _et seq._
Horse-power, 75
Hyaloplasm, 161
Iatro-chemistry and mechanics, 34-5
Idioblasts, 167
Infusoria, death of, 337
Instability, 188 _et seq._
Instinct, of life and death, 345 _et seq._
Intussusception, 291
Invariant, mass the first, 63
Irreversibility, of vital energies, 104
Irritability, 27, 196 _et seq._
Isodynamism, 142
Isomorphism, 286
Ka, the, 8
Kilogrammetre, 72, 75; per second, 75
Kilowatt, 76
Kinetic theory, 39, 62
Knot, the vital, 21
Leucines, 183
Leucites, 163
Life, defined, 28; latent, 233; physico-chemical theory of, 36; elementary, 321
Linin, 163
Mass, and matter, 63
Materialism, 34
Matter, 37, 60, 62; and mass, 63; two kinds of, 63; life of, 236 _et seq._; brute and living, 249 _et seq._; organization and constitution of, 255 _et seq._; defined as extension, 64; conservation of, 65
“Memory,” of metals, etc., 265
Merotomy, 47
Metabolism, 117
Metazoa, evolution and death of, 340 _et seq._
Meteoric cosmozoa, 252
Micellar theory, 166 _et seq._
Microcosms, 163
Micro-organisms, culture of, 297
Mitomes, 169
Mobility of stars, 260
Modality, twofold, of soul, 12
Molecules, organic, 254
Monism, 34, Chap. iv. _passim_, 63
Montpellier, the school of, 35
Motion, cause of, 71; kinetic conception of molecular, 263
Morphogenesis, idea of, 46
Movements, internal of bodies, 262; Brownian, 266 _et seq._
Mutability, 80, 188 _et seq._; of living matter, 259 _et seq._; of brute bodies, 259 _et seq._
Necrobiosis, 326
Neo-vitalism, 15, 29, 32
Neurility, 27
Nickel, steels, 277
Nisus _formativus_, 46
Nous, the, 18, 239
Nucleins, 179, 180 _et seq._
Nucleo-albuminoids, 178; -proteids, 177 _et seq._
Nucleus, 163 _et seq._; hexonic, 186
Nutrition, directed, 205, 209 _et seq._, 227 _et seq._, 290 _et seq._
Organogenesis, 282
Organs, organization of, 314; death of, 315; perfect, 319
Pangenes, 167
Panspermia, 252
Parameter, mass the mechanical, 63
Phenomena, vital, 44, 51, 189; modes of motion, 61
Photography, colour, 277
Physiology, general, 56; cellular, 56
Plants, and immortality, 330
Plasomes, 167
Plurivitalism, 25
Power, 70, 75
Principle, vital, 15 _et seq._
Properties, vital, 25, 103
Proteids, 178
Protoplasm, 109 _et seq._, 175 _et seq._, 231 _et seq._; life in crushed, 257 _et seq._
Protozoa, immortality of, 352 _et seq._
Psyche, 239
Pyrozoa, 253
Regeneration, normal, 205; accidental, 206
Reparation, mechanism of, 288
Repose, functional, 109, 217 _et seq._
Reserve stuff, 106 _et seq._, 212, 230 _et seq._
Rachidian, soul, 12
Senescence, 305 _et seq._
Sensibility, in brute bodies, 244
Solidarity, of anatomical elements, humoral and nervous, 317
Soul, the, 7 _et seq._
Space, 69
Specificity, vital, 48
Spireme, 165
Spongioplasm, 162
States, initial and final, 128
Swelling, 167
Synthesis, organizing, 109
Tagmata, 169, 175
Teleology, 43
Tetanus, bacteria of, 193
Thermogenesis, 140
Time, 69
Tonus, muscular, 119
Trees, and immortality, 330 _et seq._
Tripod, vital, 2, 314
Turgescence, 168
Universe, the, mechanical explanation of, 60; the end of the, 95
Unity, chemical, of living beings, 173 _et seq._, 321; morphological, 321
Vacuoles, 113
Vibrion, septic, 193
Vis viva, 73
Vital properties, theory of, 29 _et seq._
Vitalism, 6, 7, Chap. iii. _passim_; physico-chemical, 29
Vitality, phenomena of, 216
Vortex, vital, 105, 120, 229 _et seq._
Vulcans, 26-7
Weight, energy of position, 64; conservation of, 65; movement under action of, 271 _et seq._
Work, 70, 72; and force, 74, 77; converted into heat, 92; physiological, 103
Xanthic bases, 180
Zones, metastable and labile, 301
THE WALTER SCOTT PUBLISHING COMPANY, LTD., FELLING-ON-TYNE.