Читать книгу The Pros and Cons of Vivisection - Charles Richet - Страница 5

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First of all I declare, without fear of being contradicted by any physiologist, that the past has witnessed much excess, almost guilty excess, and that at the present time excess might still be pointed out. I quite believe that, even to-day, here and there in the laboratories of physiology, young men may be found who are no doubt enamoured of science, but who have not sufficiently reflected on the nature of pain, and consequently, through lack of sympathy, are callous and indifferent about inflicting useless, or almost useless, tortures on innocent animals. On this point I might mention numerous facts which are extremely painful to relate, but which nevertheless we must have the courage to acknowledge and denounce.

To quote only one instance, a most abominable one, I will mention the following, which is old, dating back about forty years. In the veterinary schools, surgical studies, at that time, were not made on the dead carcase, but on the living animal; so that the wretched victim, generally a horse, served as a subject, while yet alive, for all the operations which the veterinary surgeon is called upon to perform. The detestable argument given at that time to qualify this barbarism was that the veterinary surgeon should be familiar with the reactions of a living animal, and that, as a guarantee of being able to perform an operation on a diseased horse, he should have already practised the same operation several times, not on the dead body, but on a horse full of life and vigour, able to defend himself, and obliged therefore to be held down motionless by special processes. But this is scarcely a sufficient justification. But happily such things no longer exist; public opinion, stimulated no doubt by the writings of anti-vivisectionists, has altered the customs of veterinary experimentalists so well that in no veterinary school to-day are surgical exercises now performed on other than the dead body.

Thus, as far as surgery is concerned, unquestionably all vivisection should rigorously be proscribed. I will discuss later the point as to whether this interdiction should be moral—that is, recommended as a precept of humanity, or enforced by law under penalty of imprisonment or fine. For the moment it will suffice to establish the point that no living animal should serve for surgical exercises.

I will go even further, and on this point my opinion will perhaps clash with that of some of my friends and colleagues: I maintain that no experimental physiological demonstrations which involve suffering should ever be performed. Much abuse has taken place in experimentation for instruction, which is a very different thing from experimentation for investigation. Important as it may be to demonstrate physiological facts to students, I do not consider that this importance is greater than the suffering of an animal. And here again I will take an example, that of the distinction between the motor nerves and the sensory nerves.

Magendie, in 1811, following up an idea somewhat hesitatingly put forth by Charles Bell a few years previously, demonstrated that the anterior nerve roots, starting from the spinal cord, give movement to the muscles, whilst the posterior roots are exclusively devoted to sensibility; so that there are anterior motor nerves and posterior sensory nerves. In order to demonstrate this, it is evidently necessary to operate on a living and sensitive animal.

The discovery was confirmed by several physiologists between 1830 and 1850; and I do not think we have the right to repeat this cruel experiment for the sake of the instruction of students. It is not only cruel, but also useless, for it consists in laying bare the anterior and posterior nerve-fibres of the spinal cord, with the sole object of allowing students to see that the excitation of the anterior nerve-fibres provokes movement and not pain, whilst the excitation of posterior nerve-fibres provokes pain and not movement. Now, in order to make students clearly understand this distinction between the motor and sensory nerves, I require only a blackboard and a piece of chalk; and I claim that, with a piece of chalk and a blackboard, I am able to explain very clearly all the details of this phenomenon. Not only does the chalk suffice for comprehension as well as vivisection, but it is better; because the experiment is so delicate, so difficult, and, in order to be understood, it must be observed so narrowly, so closely, that out of the whole class scarcely two or three students are able to follow the experiment. The rest of the class have before them only the frightful spectacle of the reactions of a mutilated, suffering animal under excitations which are made in the very depths of a wound on organs which they do not see.

This experiment is rendered more particularly cruel by the fact that anæsthetics cannot be used, precisely because the point in question is the sensibility or non-sensibility of the animal, and consequently by its very nature the operation cannot be made on the insensible animal.[1]

And now, at once entering further into the difficulty of the problem of vivisection, we may ask ourselves if we have the right to allow demonstrations of experimental physiology on living animals that have been rendered insensible by chloroform.

Although, further on, I intend coming back to this important question of anæsthetics, I will say at once I do not understand what repugnance there can be to operating upon an anæsthetised animal. Once he is insensible he cannot suffer; why hesitate, therefore, to perform prolonged experiments upon that insensible being? It appears to me just as inhuman to boil milk as to excite the pneumogastric nerve of a dog rendered incapable of suffering. The milk does not suffer; the dog does not suffer; in both cases it is living matter, but insensible living matter. Consequently, as far as physiological demonstrations are concerned, every individual capable of reflection should recognise that there is nothing wrong in experimenting upon animals that cannot suffer.

I shall, however, make two restrictions. The first is that professors should energetically call the attention of the pupils to the fact that the animal is insensible, and that no one has the right to make the experiment upon a sensitive animal; that we, physiologists, more than all other men, are under the obligation of dealing humanely with animals. The professor of physiology should take advantage of the occasion to develop in his hearers the best and noblest sentiments, those of pity and of generosity. In a word, he should excuse himself, so to speak, for performing vivisection, and prove that such is only legitimate when it entails no suffering.

The second restriction is that the animal thus chloroformed or anæsthetised should never be permitted to awaken. If he shows the slightest sign of sensibility, he should be given chloroform until anæsthesia is complete, and, finally, he ought to be killed after the experiment, without allowing him to regain consciousness.

After all, death under these conditions is a painless end. We ourselves, who will disappear after a long, and certainly painful, agony, in those weary moments of pain which will precede our end, shall envy that absence of suffering, that rapid end of all pain, which is the death of an animal under an anæsthetic.

Let us, therefore, banish every painful experiment the object of which is purely didactic. Moreover, I fail to see what experiments in painful vivisection are necessary for the teaching of physiology. Studies on reflex movement can be made perfectly well on a decapitated animal; and in that case it is well understood that there can be no question of pain; for it would be absurd to suppose that the spinal cord possesses the power of receiving the notion of pain. Such a supposition would mean the negation of the best-established facts of physiology.

Experiments on the heart (notably of the frog and the tortoise) are performed very much better on a decapitated animal than on an animal which is intact; and experiments can even be made on the heart separated from the organism. It would be downright puerile to lack the courage to watch the beating of the living heart of a dead tortoise! As for the mammalia, all experiments on the heart and on the respiration necessary in a course of lectures on physiology are admirably carried out on an animal rendered completely insensible.[2]

We have not, however, quite finished with the difficulties of physiological instruction: there are certain poisons for which chloroform cannot be used.

As the essential property of chloroform is to deaden the nervous cells, the effects of some poisons cannot be studied in an animal profoundly chloroformed. We can watch very well indeed the effects of carbonic oxide, which poisons the blood, but many other poisons no longer produce their characteristic symptoms; nevertheless, it is of the highest importance to show medical students the effects of certain formidable toxic substances.

Permit me to quote myself. However little I may be a partisan of painful experimental demonstrations, I make one exception for an experiment which I consider it essential to present, in all its horror, before the young men who attend my lectures. I refer to absinthe. If two or three drops of essence of absinthe are injected into the veins of a dog, he is at once seized by a violent attack of epilepsy with hallucinations, convulsions, and foaming at the mouth. It is truly a terrible sight, one which fills with disgust and horror all who have witnessed this experiment. But it is precisely for the sake of arousing this disgust, this horror, that I perform the experiment. The unfortunate dog will, during ten minutes, have had an attack of intoxication and absinthian epilepsy; but at the end of an hour he will have recovered completely. At the same time, the two hundred students who have witnessed this hideous spectacle will retain, profoundly engraved on their minds, the memory of that epileptic fury, a memory which will remain with them to the end of their days. They will then be able, by their propaganda against absinthe, to exercise around them a salutary influence, to prevent perhaps ten, fifteen, one hundred human personalities from destroying themselves by the use of this abominable poison. After all, it is better to give a dog ten minutes of absinthism than to allow twenty human families to be plunged, by absinthism, into degradation and misery.

Finally, as far as surgical exercises are concerned, they should never be made on a living animal; as regards demonstrations of experimental physiology intended for instruction, they should be made only on decapitated or anæsthetised animals; and as for intoxications,[3] save on very rare and altogether exceptional occasions, they should not be made the object of experimental demonstrations.

It seems to me that these formal declarations might be accepted by every physiologist as well as by every anti-vivisectionist.