Popular Science Monthly/Volume 4/April 1874/Vivisection
By MICHAEL FOSTER, M. D., F. R. S.
PROFESSOR OF PHYSIOLOGY IN THE UNIVERSITY OF CAMBRIDGE.
IN the following pages I propose to inquire whether it is desirable that physiologists should continue the practice of what is commonly called vivisection, to which they have hitherto been accustomed. By vivisection I understand the operating with cutting instruments or by other means on the still living bodies of animals. The word "living" requires, perhaps, some further definition. In the long series of changes through which the body of a living animal passes, from full functional activity to complete decomposition, there are three chief stages, each of which may be arbitrarily taken as the end of life. There is the time at which consciousness is lost, the time at which the breath stops and the heart ceases to beat, and the time at which the muscles become rigid with the death-stiffening. The succession of the three events is always in the same order, but the interval of time between any two of them varies within very wide limits. For our purposes it will perhaps be best to take the second as marking the end of life, to say that an animal is still alive so long as the heart is beating, and air enters into and issues from the chest.
It is very desirable that a discussion, the decision upon which must be of the utmost importance to physiology at least, should not be turned aside to any false issues. The question whether vivisection is a bad thing is in no wise settled by asserting that there are many things equally bad. Thus, to say that the evil wrought upon animals in the name of science is but a flea-bite compared to that done in the name of sport, is simply to bring forward a tu quoque argument of no real worth, except to stop the mouths of particular opponents. When an ardent sportsman, or when one, no sportsman himself, but having a theoretical admiration of the pleasures of the field, declaims against vivisection, it may be worth while to remind such a one of some of the agonies of sport—of the scenes which accompany a battue or a pigeon-match; of wounded birds dragging their maimed bodies to some hidden covert, there to die a lingering death; of the piercing squeals of the hunted hare; of the last moments of the brave fox, when, after a fruitless struggle, the time comes for his living body to be torn by the pursuing hounds; to ask him how often a living object of sport is by some purposeful, sudden blow, humanely killed "to put it out of its misery;" to suggest to him, as a matter of reflection, that, had we any satisfactory measure of pain, it would be found that all the pain which physiologists have caused, since their science began, is less than that which the animal creation has suffered in the field from the hands of the members of the two Houses of Parliament since the last general election. It may be of use to say this to a sportsman; but vivisection is not thereby justified. It is no use saying it at all to those who are now agitating this question. They are equally opposed to cruelty in sport as to cruelty in science; but they are also wise in their generation. They see that there is far more hope of putting down the one than the other. Biologists and physiologists are at the present moment clearly in disrepute. To call them atheists, is to show one's self a man of spirit and intelligence. Following out their own science, along the path Nature has pointed out to them, they have run counter to many established opinions and cherished views. Divorced by the divergence of their respective methods in large measure from the mathematicians and physicists, to whom orthodoxy is easy, accused of materialism, active in the support of Darwinism and evolution theories, believed by the many to have no faith—their position not a little resembles that of the Jews in the middle ages; they are just in the condition in which the accusation of cruelty is most tellingly made and most readily credited against them by a vulgar public. This the opponents of vivisection know full well; and therefore it is against the physiologists and not against the pigeon-shooters that they make their complaint. They are even willing, at the present, to use the latter against the former. By-and-by, if they are successful in this, they will move against sport, on the ground that it is far more cruel and has far less justification than the vivisection which has been done away with.
Nor is it any use to tell a far larger class, the eaters of meat, that the pain which physiology has caused since the time of Galen is far less than that which in any one week is caused in butchers' shambles in providing flesh to fill the mouths of the people of London.
Nor is it, on the other hand, any use to say that because many physiologists are kindly, humane men in private life, therefore the accusation of cruelty brought against them must be false. I know a physiologist who, after a day spent in experimental work, may be seen sitting in the evening with a favorite cat on his lap, an old dog by his side, and a new one at his feet; but I would not therefore guarantee that he had not been cruel in the morning. He might be an angel in the bosom of his family, but a demon in the laboratory. I know a physiologist, of whom his friends have said that, had he not been so amiable, he might have made a noise in the world, and yet who at the present moment is being accused of brutal cruelties. I feel that the accusation might be true.
Nor is it of any use to say, though it may be said with perfect truth, that a great deal of the present agitation against vivisection is one of the many fruits of a mawkish sentimentalism which is stealing over the present generation, and by a lessening of manliness is curtailing the good effects of increased enlightenment. The foolish of this world are often used to correct the wise; and actions brought about by a wrong sentimentalism may be in themselves right and good.
The question whether it is desirable that man should continue to inflict the pains of death, or pains without death, on other animals, and, if so, within what limits, is one which must be argued out on its own merits alone, and the discussion of it will not be advanced by irrelevant considerations such as these on which we have dwelt.
There are two aspects of the inquiry—one from the side of man, the other from the side of the animal. Let us first consider the question from the point of view of the animal.
We have to determine the principles which govern or should govern the conduct of man toward animals. One broad principle may be briefly stated: Unless man destroys animals, animals would soon destroy man. Mr. Tennyson has told us—
"Nature is one with rapine, a harm no preacher can heal;"
and Mr. Darwin has shown that the lives of all living beings are shaped by "the struggle for existence." Man's life is a struggle for existence with his fellow-men, with living animals and plants, and with the lifeless forces of the universe. The very conditions of his existence lay upon him the burden, and in so doing give him the right, to use the world around him, the lives of animals included, to aid him in his strife. Imagine the results of forbidding man to take away the lives of animals. Suppose, for instance, the whole human race were to form itself into a Society for the Prevention of the Destruction of Tigers. How many generations would pass before "the last man" provided a tumultuous crowd of tigers with the last human meal?—possibly the indefatigable secretary of the Society sealing with his death his loyalty to the cause. Or, since tigers, like man, are carnivorous, and might therefore be supposed more worthy of death than herbivorous creatures, let us suppose the efforts of the Society to be directed toward the preservation of sheep. How many generations would pass before the face of the earth were covered with woolly flocks, and man were driven to lead a laborious, frugivorous, arboreal life on the tree-tops, or to earn a scanty subsistence on resuscitated Pfahlbauten, as being the only places where the necessities of the sheep would permit him to dwell? Did the reader ever by chance descend, at early dawn, into the kitchen and watch the convulsive agonies of a writhing heap of cockroaches drowning in the watery trap set for them by the cook overnight? What a scene of unutterable woe is that when judged from the stand-point of the cockroach! But, if man were to deny himself the right of vivisection or vivipression over the vermin which infest his home and bed, what would come of it?
To be serious: man, if he is to live and prosper, must kill other animals. It is a duty laid upon him by the nature of things; a duty, and therefore a right. Self-preservation demands it. But what do we mean by self-preservation? Can we draw a line and say that he is justified in slaying an animal for this purpose and not for that? We can only do so by applying the test of whether the death of the animal is useful to him or not. Whenever or wherever the death of an animal is of advantage either to himself or to the human society of which he is a unit, he is justified in slaying that animal.
The success of the human race in the struggle for existence depends on man's being well fed; man is therefore justified in slaying and eating a sheep. The success of the human race in the struggle for existence is dependent on knowledge being increased; man is therefore justified in slaying a frog or a rabbit, if it can be shown that human knowledge is thereby enlarged.
Death is in itself painful. It is only by special means that the pangs amid which the ties of life are loosened can be done away with. The slaughter of an animal is therefore of necessity painful, except in the special cases where means have been taken to do away with pain. In ninety-nine cases out of a hundred, when an animal is slaughtered by man, it is the death of the animal which benefits man, the pain itself which accompanies the death does him no good at all. While justified, therefore, in killing the animal, he is not justified in causing it pain. He is bound, in fact, to kill the animal in such a way as to cause as little pain as is consistent with his own interest. The death of a sheep in a butcher's slaughter-house is painful; but men cannot therefore be said to do wrong in killing a sheep for food. They kill it with as little pain as is under the circumstances possible. They could not make the pain less, except by the introduction of elaborate and costly methods which would probably ruin the butcher or spoil the meat, or at least, in the present state of our knowledge and of the market, do damage to the interests of mankind. The death of an ox, again, is more painful than that of a sheep; but men do not therefore feel bound to live on mutton alone. They consider that the advantages of a mixed diet of beef and mutton justify them in inflicting that additional quantity of pain which is suffered whenever an ox is felled.
In short, this, under one aspect, is a selfish world. The struggle for existence is its guiding principle. If we believe that man is to govern the world, and he must either govern or succumb, then we must be prepared to use animals selfishly, if you please to call it so—to use animals for our advantage—to kill them when we have need of their deaths—to kill them with pain when the pain is for our benefit; and, inasmuch as the greater includes the less, to inflict pain without death where their pain does us good. Our good is, in fact, the rule of our conduct toward animals. Whenever an animal is killed by man, or suffers pain at the hand of man, without benefit to man, or where the same benefit could be gained without the death or without the pain, then the death or the pain can be no longer justified. The man who inflicts them is a cruel man; he no longer does good, but harm, to humanity, and humanity ought to stop his hand.
I feel that I ought almost to apologize to the reader for having spent so much of his time over what are almost truisms; but so many absurd statements are continually being made, and so many whimsical ideas broached, that it seemed desirable to have a clear understanding concerning the principles which should guide our general conduct toward animals before discussing the special subject of vivisection.
We have now to inquire whether the deaths and pains which the word vivisection implies are, or have been, wrought for the benefit of mankind, inasmuch, as they have led to knowledge and power which could not otherwise have been gained; or whether they had not been wrought for the benefit of mankind, inasmuch as they have not led to knowledge and power, or the power and knowledge might have been gained in some other way, or, being gained by many deaths and much pain, have been so small that mankind could well have done without them. I introduce the word death as well as pain, because, in spite of the etymology of the word, and the fact that vivisection suggests to the public mind pain only, and not death at all, the truth is, that in at least the great majority of cases vivisection does or ought to mean death only, and not pain at all. In the minds of those ignorant of physiology—and they are foremost, if not alone, in blaming vivisection—much confusion has arisen from the different meanings attached to the words "life" and "living." I alluded to these in the beginning of this paper. To many such it is perhaps a revelation to learn that an animal may be kept alive—that is, with its heart in full working order, and its respiratory movements continuing with perfect regularity—for hours and hours after all signs of consciousness have disappeared. All operations performed on such an animal would come under the term vivisection; but, in the total absence of all signs of consciousness, it would be absurd to speak of pain. It would perhaps be a still greater revelation to such to learn that a frog, at a later stage in the series of events which we class together as death—when its brain and spinal cord have been instantaneously destroyed by an operation the pain of which may be said to be infinitesimal, and its heart removed at a time when feeling is impossible—may yet be made by proper means to kick and jump and move its body about in almost all possible ways. Any operation performed on the body of such a frog would by many be still called vivisection; but, to speak of such a mere mass of muscle and nerve as suffering pain, is about as truthful and rational as to say that it is cruel to cut down a tree, though a silly, ignorant looker-on might shriek when the leg moved, for about the same cause and with the same reason that the African grovels before his fetich.
Did the reader ever see a rabbit completely under the influence of chloral? Lying prostrate, with flaccid limbs, with head sunk back on the limp neck, motionless and still, at first sight, it seems quite dead and gone. But a gentle heaving of the body, a rise and a fall every few seconds, tells you that it still breathes; and a finger placed on the chest may feel the quick throb of the still beating heart. You pull it and pinch it; it does not move. You prick with a needle the exquisitely-sensitive cornea of its eye; it makes no sign, save only perhaps a wink. You make a great cut through its skin with a sharp knife; it does not wince. You handle, and divide, and pinch nerves which, in ourselves, are full of feeling; it gives no sign of pain. Yet it is full of action. To the physiologist, its body, though poor in what the vulgar call life, is still the stage of manifold events, and each event a problem, with a crowd of still harder problems at its back. He therefore brings to bear on this breathing, pulsating, but otherwise quiescent frame, the instruments which are the tools of his research. He takes deft tracings of the ebb and flow of blood in the widening and narrowing vessels; he measures the time and the force of each throb of the heart, while by light galvanic touches he stirs this part or quiets that; he takes note of the rise and fall of the chest-walls, as they quicken or grow slow, as they wax or wane, under this influence or that; he gathers the juice which pours from one or another gland; he divides this nerve, he stimulates that, and marks the result of each; he brings subtile poisons to bear on the whole frame, or on parts; and, having done what he wished to do, having obtained, in the shape of careful notes or delicate tracings, answers to the questions he wished to put, he finishes a painless death by the removal of all the blood from the body, or by any other means that best suit him at the time. I am not exaggerating when I say that this is at the present day one of the commonest forms of vivisectional experiment; this is what newspaper writers speak of as "torture," and, on the strength of it, accuse cultivated physiologists of barbaric cruelty.
A dog under chloroform or morphia may be brought to very nearly the same condition as a rabbit under chloral; but, as far as my experience goes, the same long duration of complete quiescence is maintained with greater difficulty. Dogs sometimes howl under chloroform or morphia when nothing is being done to them, and under circumstances in which they can be suffering no pain. At the moment when the chloroform begins to take effect upon them, when probably confused carnivorous visions chase through their brains, the howling is often excessive. Any one who knows any thing about the administration of chloroform to human beings, is well aware how frequent cries and noises are in the stage of excitement, and how little dependence can be placed on them as signs of pain.
In a large number of cases, then, where anæsthetics of one kind or another are used, vivisectional experiments cause no pain at all; and, as far as I know, in this country, at least, physiologists always use anæsthetics where they can. They do so not only for the sake of the animal, but also for the sake of the experiment itself. Unless they are studying actual manifestations of feeling, pain, with all its consequences, is a disturbing element which must by all possible means be eliminated, if the experiment is to have its due value. The apparent lifelessness of the animal is the physiologist's opportunity; struggling limbs would utterly defeat his aims, and a sudden start might wreck his whole experiment. Chloroform and other anæsthetics have immensely lessened human suffering, not only by simply diminishing pain, but even still more by putting it in the power of the surgeon to perform operations which he otherwise would not dare to attempt. In the same way they have powerfully aided the progress of physiology, by rendering possible new experiments, and by allowing the investigator to analyze securely phenomena which otherwise would, perhaps forever, have remained confused through the disturbances caused by pain.
There are some experiments, however, requiring vivisection, in which the use of chloral or other anæsthetics is, for various reasons, inadmissible or undesirable. These form two classes. In the first and most numerous, the experiment is generally a short one, and quickly carried out, and the pain slight and transient. It is, of course, impossible for any one to judge truly of the pain felt by any other body, and we may err in two ways in estimating the pain felt by animals. We may over-estimate or under-estimate it. Perhaps a rough but tolerably safe test of great pain or distress may be gained by noting whether the animal is willing to eat or not. When a rabbit, for instance, not previously starved, begins to munch carrots immediately after an operation, or even continues to munch during the greater part of the time the operation is being performed, it is only fair to conclude that the operation cannot be very painful. I may add that, in the experience of experimental physiologists, the skin of the dog and the rabbit—allowance being made for individual peculiarities—is not nearly so sensitive as the human skin.
The second class of experiments carried on without anæsthetics—those entailing a considerable amount of pain—are not only by far the least numerous, but must of necessity become less and less numerous as physiology advances. The end which the physiologist has in view is to analyze the life of any being into its constituent factors. As his science advances, he becomes more and more able to disengage any one of these factors from the rest, and so to study it by itself. He can already, as we have seen, study the complicated phenomena of the circulation of the blood, of respiration, of various kinds of movement, quite apart from and independent of the presence of consciousness. As his knowledge widens and his means of research multiply, this power of analysis will grow more and more; and by-and-by, if physiology be allowed free scope for its development, there will come a day when the physiologist, in his experimental inquiries, will cause pain then, and then only, when pain is the actual object of his study. And that he will probably study best upon himself.
At the present day, the greatest amount of pain to animals is probably caused in experiments which perhaps hardly come under the title of vivisection—experiments in which the effects of starvation or of insufficient food, or the actions of poisons, are being studied. These, however, lead to valuable results. The pain which is the greatest in amount, and the least worthy in object, is the pain which comes to animals whose bodies have been used as tests to ascertain the poisonous nature of some suspected material; but this is a matter of the witness-box, not of physiology.
We may conclude, then, that physiologists are the cause to animals of much death, of a good deal of slight pain, and of some amount of severe pain. A very active physiologist will, for instance, in a year, be the means of bringing about, for the sake of science, as much death as a small village will, in a week, for the sake of its mouths and its fun, and will give rise to about as much pain as a not too enthusiastic sportsman in a short sporting-season.
We have now to ask: What justification does he plead for this death and this pain? What good to mankind is thereby wrought which could not otherwise be gained?
His answer is, that the science of physiology is thereby advanced; that our knowledge of the laws of life has, in the main, been won by experiments on living animals. He, of course, cannot, and no one can, tell the "might have been." Without any such experiments, physics and chemistry, aided by mathematics, might have synthetically resolved the problems of life (though even then it might be said that both physics and chemistry sprang from the older biologic lore, and not so long ago a common physiological preparation, the muscle and nerve of a frog, started a new epoch in physics); but, as a matter of history, experiments on living animals have been the stepping-stones ofprogress.
The great Vesalius, the founder of modern anatomy, turning his thoughts to the uses of the structures he had so well described, saw clearly that the problems opening up before him could be settled only by vivisection. In his great work, "De Corporis Humani Fabrica," may be read the evidence, not only that he performed experiments on living animals, but that, had he not in so inscrutable a way forsaken the arduous pleasures of learning for the gossip of a court, those experiments would have led him up to and probably beyond the discovery which years afterward marked an epoch in physiology, and made the name of Harvey immortal. He, indeed, sowed the seed whose fruit Harvey reaped. The corner-stone of physiology, the doctrine of the circulation of the blood, was not built up without death and pain to animals. To-day, it is true, much of the evidence touching the flow of blood may be shown on a dead body, yet the full proof cannot be given even now without an experiment on a living creature; and certainly Harvey's thoughts were guided by his study of the living, palpitating heart, and the motions of the living arteries, quite as much as by the suggestions coming from dead valves and veins.
After Harvey came Haller, whose keen intellect dispersed the misty notions of the spiritualists, and by the establishment of the doctrine of "irritability" laid the foundations of the true physiology of the nervous system: he too, in his work, wrought death and suffering on animals.
Another great step onward was made when Charles Bell and Magendie, by experiments on animals more painful than any of the present day, traced out the distinction between motor and sensory nerves; and yet another, when Marshall Hall and others demonstrated by vivisections the wide-spread occurrence and vast importance of reflex actions.
What was begun with death and pain has been carried forward by the same means. I assert deliberately that all our real knowledge of the physiology of the nervous system—compared with which all the rest of physiology, judged either from a practical or from a theoretical point of view, is a mere appendage—has been gained by experiment, that its fundamental truths have come to us through inquiries entailing more or less vivisection. By meditating over the differences in structure visible in the nervous systems of different animals, a shrewd observer might guess at the use of some particular part; but till verified by experiment, the guess would remain a guess; and experiment shows that such guesses may be entirely wrong. Where experiment has given a clew, careful observations have frequently thrown light on physiological problems. Without the experimental clew, the phenomena would ever have remained a hopeless puzzle, or have served to bolster up some baseless fancy. What disease, or what structure in what animal, could ever have made us acquainted with that "inhibitory" function of the pneumogastric nerve which the vivisectional experiment of Weber first detected? What a light that one experiment has thrown on the working of the nervous system! What disease could have told us that which we have learned from the experiments of Du Bois-Reymond and of Pflüger? Where would physiological science be now if the labors of Flourens, Brown-Séquard, Schiff, Vulpian, Goltz, Waller, and others, were suddenly wiped away from the records of the past? Yet each of these names recalls long series of experiments, some of them painful in character, on living animals.
I repeat, take away from the physiology of the nervous system the backbone of experimental knowledge, and it would fall into a shapeless, huddled mass.
The chemistry of living beings, one would imagine at first thoughts, might be investigated without distressing the organisms which formed the subjects of research. The labors of Lavoisier and Priestley, who first made clear the chemistry of respiration, if they entailed no use of the knife, caused at times a no less painful suffocation; while the great advances which have been made in this branch of the study during the last quarter of a century, and are still being made, necessitate almost daily vivisection, in order that the gases of the blood may be studied in exactly the same condition as they are in the living body. Even still more bloody has been the path by following which we have gained the knowledge we now possess of the chemistry of digestion and nutrition. I have only to mention the names of Bidder, and Schmidt, and Bernard, to call to the mind of the physiological student important results, nearly all reached through vivisection. The shifts and changes of the elements within our body are too subtile and complex to be divined from the results of the chemical laboratory; the physiologist has to search for them within the body, and to mark the compounds changing in the very spot where they change; otherwise all is guess-work.
Among the labors of the present generation, none perhaps have already more far-reaching results, none hold out more promise of fruit in the future, than those which bear on the influence of the nervous system over the circulation of the blood and over nutrition. The knowledge we are gradually acquiring of the subtile nervous bonds which bind together the unconscious members of the animal commonwealth, which make each part or organ at once the slave and guardian of every other, and which with cords of nervous sympathy draw each moiety of the body to work for the good of all, is putting a new aspect on physiology, and throwing many a gleam of light into the very darkest regions of the science. The words "inflammation" and "fever," bandied about of old as mystery-words, sounding much but signifying little—shuttlecocks tossed to and fro from one school of doctrinaire pathologists to another—now at last, through the labors of modern physiology, seem in a fair way of being understood. That understanding, when it is complete, will have been gained step by step through experiments on living animals, one of the first of which was Claude Bernard's research on vaso-motor nerves.
There still remains the question, What good does physiology bring to mankind? Of the value of physiology as a not insignificant segment of the circle of universal knowledge, nothing need be said; where saying aught is necessary, it would be useless. Nor need much be said concerning the practical value of physiology as a basis for the conduct of life. So long as men refuse to learn or to listen to physiology in order that they may the better use their bodies, it would be hopeless and useless to talk of the day when they may come to it for instruction how to form their minds and mould their natures. It will be enough for my present purpose to point out briefly the relations of physiology to the practical art of medicine.
These are twofold. In the first place, the medical profession is largely indebted to physiology on account of special discoveries and particular experimental researches. If we regard the profession simply as a body of men who possess or should possess a remedy for every disease, this may seem an exaggerated statement. Many of the remedies in use or in vogue at the present day have been discovered by chance, borrowed from ignorant savages, or lighted on by blind trials. Physiology can lay no claim to the introduction of opium or quinine. Where specific remedies have been suggested by physiological results or theories, it has not seldom happened that the remedies, though useful, have been given for a wrong reason, or have done good in a way which was not expected.
But if we look upon the medical profession as a body of men, cunning to detect the nature and to forecast the issues of the bodily ills under which we suffer, skillful in the use of means to avoid or to lessen those ills, rich in resources whereby pain is diminished and dangerous maladies artfully guided to a happy end, then we owe physiology many and great debts. Did the reader ever suffer, or witness others suffer, with subsequent relief, a severe surgical operation? If so, let him revere the name of John Hunter, the father of modern surgery. But Hunter was emphatically a physiologist; his surgery was but the carrying into practice of physiological ideas, many of which were got by experiments on living animals. Does the reader know that in all great surgical operations there are moments of imminent danger lest life steal away in gushes of blood from the divided vessels, danger now securely met by ligatures scientifically and deftly tied? Does he know that there was a time when the danger was imperfectly met by hot searing-irons and other rude means, and that the introduction of ligatures, with their proper application, is due to experiments, cruel experiments, if you like, on dogs and other dumb animals, experiments eminently physiological in their nature, about which much may be read in the book of "Jones on Hæmorrhage?" Even now, year by year, the scientific surgeon, by experiments on animals, is at once adding to physiological knowledge and bettering his treatment of wounded or diseased arteries. Has the reader seen any one once stricken by paralysis, or bowed down by some nervous malady, yet afterward made whole and brought back to fair, if not vigorous, health? The advice which turned such a one toward recovery was based on knowledge originally drawn from the vivisectional experiments of physiologists, and made safe by matured experience. Or has he watched any dear friend fading away in that terrible malady diabetes, after rejoicing that for a season he seemed to be gathering strength and ceasing to fail, even if not regaining health? The only gleam of light into that mysterious disease which we possess, came from the vivisectional researches of Claude Bernard on the formation of glycogen in the liver; and by judiciously acting upon the results of those researches the skillful physician can sometimes stay its ravages. He cannot cure it even now; and unless some empiric remedy be found by chance, will never cure it, until, by the death of many animals in the physiological laboratory, the mystery of the glycogenic function of the liver be cleared up.
But why need I go on adding one special benefit to another? They may all be summed up in one sentence, which embodies the whole relation of physiology to the medical profession.
The art of medicine is the science of physiology applied to detailed vital phenomena by the help of a wisdom which comes of enlightened experience, and an ingenuity which is born of practice. Were there not a single case on record in which physiology had given special and direct help to the cure of the sick, there would still remain the great truth that the ideas of physiology are the mother-ideas of medicine. The physiologist, unincumbered by the care of the sick, not weighted by the burden of desiring some immediate practical result, is the pioneer into the dark places of vital actions. The truths which he discovers in his laboratory pass over at once to the practitioner, busy in a constant struggle with the puzzling complexity of corporeal events: in his hands they are sifted, extended, and multiplied. The property of the physiologist alone, they might perhaps lie barren; used by the physician or surgeon, they soon bear fruit. The hint given by a physiologist of the past generation becomes a household word with the doctors of the present, and their records in turn offer rich stores of suggestive and corrective facts for the physiologists of the generation to come. Take away from the practical art of medicine the theoretical truths of physiology, and you would have left a crowd of busy idlers in full strife over fantastic ideas. The reader has laughed with Molière over the follies of the doctrinaire physicians of times gone by. He has to thank experimental physiology that he has not the same follies to laugh over and to suffer from now. The so-called practical man is ever prone to entangle himself in and guide his conduct by baseless speculations. Such has been the case with medicine. The history of medicine in past centuries is largely occupied with the conflicts of contending schools of pathology—schools which arose from this or that master putting forward a fancy, or a fragment of truth, as the basis of all medical judgment. These have given place in the present century to a rational pathology, which knows no school and swears to the words of no master, but is slowly and surely unraveling, bit by bit, the many separate tangled knots of disease. They have given place because men have come to see that maladies can only be mastered through a scientific comprehension of the nature of disease; that pathology, the science of disease, being a part of, is from, physiology, the science of life; that the methods of both are the same, for in each a sagacious observation starts an inquiry, which a well-directed series of experiments brings to a successful end.
Many, if not most, of these experiments must be made on living beings. Hence it is that animals are killed and suffer pain, in order that physiological knowledge may be increased, and disease made less.
Take away from the art of medicine all that with which physiology has enriched it, and the surgeon or the physician of to-day would be little better than a mystery-man, or a quack vender of chance-gotten drugs. Take out of the present system of physiology all that has been gained by experiments on living animals, and the whole structure would collapse, leaving nothing but a few isolated facts of human experience.
As far as we can see, what has been will be. The physiology of the future, if not hampered by any ignorant restraint, will, out of the death of animals, continue to press further and further into the mystery of—and year by year bring the physician, and not the physician only, but every one, power to prolong, to strengthen, and to purify—the life of man. By no other way can man hope to gain this end. He is thereby justified for the death he causes and the pain he gives.
We have yet to consider this question in its other aspect; we have to examine not only the effects of vivisection as far as animals are concerned, but also its influence on man himself. Little, however, need be said. Necessary vivisection, we have shown, cannot be called cruel. The question of the necessity of any particular case can only be judged by the investigator himself. I content myself with asserting that any attempt to draw up, for the guidance of others, a general definition of necessary and unnecessary vivisection, must prove utterly futile. Only he who is making an inquiry knows his own needs. If he experiments recklessly and needlessly, he becomes cruel, and, being cruel, will thereby be the worse. But, if he experiments carefully and needfully, never causing pain where it could be avoided, never sacrificing a life without having in view some object, to attain which there seemed no other way, remembering that whoever "tortures" either dead or living nature carelessly will get no true response, there is no reason why his moral nature should suffer even ever so little tarnish. On the contrary, experience teaches us that earnest physiologists, who have killed animals in the single hope of gaining new truths or of making old ones plain, have grown more gentle and more careful the longer they worked and the more experiments they made.
The effects of vivisection on the moral nature of man may fairly be tested by experience. There are in this country several physiologists—myself among the number—who have for several years performed experiments on living animals. We have done repeatedly the things which a distinguished lady has seen fit to say "are best spoken of as nameless." I can confidently appeal to all who know us, whether they have seen any deterioration in our moral nature, as the result of our work; whether we are to-day less careful of giving pain than we were when we began to experiment; whether they can trace in us any lessening of that sympathy with dumb animals, which all men should feel even in the very thickest of the struggle for existence.—Macmillan's Magazine.
- Some writers have urged that while man is perfectly justified in killing any number of animals, he is not justified in causing pain. From the point of view of the animal this is simply a grotesque absurdity; from the point of view of man we shall have to speak of it later on.
- The great importance of the vaso-motor system justly led Mr. Huxley to introduce into his "Elementary Lessons in Physiology" Bernard's fundamental experiment with some such words as "a rabbit may be made to blush artificially by dividing the sympathetic nerve." A writer, apparently biased by the memories of his own boyhood, has accused Mr. Huxley of thereby dangerously inciting boys and girls to cruelty, as if the division of the sympathetic nerve were the sort of thing a school-boy might do with a pocket-knife and a bit of string. Is it any use to enlighten the malevolent ignorance of such minds by telling them that many physiological experiments require such skill and care as make ordinary surgical operations seem rough and easy proceedings?