CONCERNING EXPERIMENTATION OTHER THAN VIVISECTION
We must, however, give to the word "Vivisection" its largest acceptation.
It is not only a question of cutting nerves, of stimulating the glands, or
of exciting the muscles. There are experiments of much longer duration in
which there is no mutilation properly speaking, but _intoxication_,[7]
produced by the injection of poisons and disease germs.
It is, indeed, evident that pain can be provoked in other ways than by a
sharp-edged instrument, which can always be done under anaesthesia. But may
inoculation be performed? May prolonged _intoxication_ be caused? To treat
the question in all its fulness, we will put the problem in the following
manner.
In order to study a disease, have we the right to give that disease to an
animal?
For my part, there can be no doubt on the point, and I affirm that such is
our right.
As a matter of fact, and as every unbiassed person is forced to recognise,
it is only by experimentation that these diseases can be studied
thoroughly. Clinical observation, bearing exclusively upon man, can only
give incomplete results, much poorer, though its documents are
multitudinous, than the results furnished by experimentation, which can be
infinitely varied at will. If we were limited to the Hippocratic method of
observation, which consists in studying the symptoms and the progress of a
morbid affliction, we should be reduced to poor enough resources; and if
meditation on the aphorisms of Hippocrates constituted the whole extent of
our medical science, medical science would be a sad vacuum. Fortunately,
however, such is not the case. Marvellous progress has been realised, which
allows us to entertain quite other ideas than those of the Father of
Medicine on the nature of diseases, and consequently on their treatment and
their prevention. Those very persons who rise up in arms against
physiological experimentation would not, I imagine, desire to be handed
over to the care of a Hippocratic doctor if they were ill, to a doctor who
took no notice of any modern discoveries under the pretext that they were
acquired by experimentation _in anima vili_.
If, however, we wish to discuss the problem thoroughly, it will not do to
remain on indefinite ground. Let us arrive at precise facts. I will mention
only three discoveries, the importance of which is considerable, and which
have been established solely by experimentation.
First of all, there is _antisepsis_. For centuries and centuries surgeons
operated without understanding why it was that death struck down so
unmercifully those operated upon. In vain did surgeons display great skill;
in vain did the operation succeed: the patient died. Erysipelas, lock-jaw,
abscess-formation and gangrene reigned supreme. Every confinement exposed
the mother to death; the slightest wounds were followed by the most serious
after-effects; in certain amputations, for instance, the mortality was 70
per cent. No one dared to touch either the peritoneum or the joints,
because every operation on the peritoneum or on the articulations was sure
to prove fatal. But Lister and Pasteur came! These two men, simultaneously
and concurrently, demonstrated that all disease following on an operation
was the result of infection by parasites. By preventing the wounds from
being contaminated by parasites, infection was prevented; for the wounds
themselves are innocent, as long as they are not infected.
This is the astounding and simple truth which Lister and Pasteur
established. And let no one pretend it is so simple that the data could
have been furnished by clinical observation alone, for such an assertion
would be contradicted by the facts.
Thousands and thousands of surgeons, right up to 1868, had understood
nothing of infection. In order to understand this big word "infection,"
which sums up in itself the whole of surgery and the whole of medicine, it
was necessary to inject pus into animals, gather the microbes which then
developed in the blood of these animals, isolate the microbes, cultivate
them, inject them afresh, and produce an experimental disease. It was in
this manner only that we were able to understand the mechanism of
antisepsis, and, consequently, apply it to the treatment of operations and
wounds. Three or four volumes could be written on this subject alone, but
all I can attempt here is a summary of the main points. I say without
hesitation that as long as clinical medicine confined itself only to the
observation of patients, it was able to understand nothing, to analyse
nothing, to foresee nothing. It was necessary to experiment, to sacrifice a
few hundred mice, rats, and rabbits, in order to demonstrate that
erysipelas is an inoculable disease, that puerperal infection is of the
same nature as purulent infection, that all these diseases are due to
micro-organisms, and that certain substances, called antiseptics, can stop
the development of these fatal germs.
It appears quite natural to-day (and it seems to simple minds, ignorant of
the past and powerless to imagine the past, that these notions have been
current from all eternity) to know that instruments, water, and linen
heated to 120 deg. contain no living germs. But this discovery is not so very
old. It was Pasteur who, between 1863 and 1873, established it by some
memorable experiments at the cost of a little disease given to rats and
guinea-pigs.
[Illustration: PASTEUR IN HIS LABORATORY.
_facing p. 44._]
Now--and I appeal to the good sense of my readers--would it be better to
efface the suffering of those rats, those guinea-pigs, those rabbits, and
return to the olden times when the mortality in lying-in hospitals was
often 40 per cent. (it is to-day, 0.02 per cent.!)? Must we condemn Lister
and Pasteur as great criminals because they dared to inoculate microbes
into a few rabbits and bring about in those unfortunate animals--they would
have died a long time ago even without that--experimental ailments in order
to ward off malignant diseases from thousands and thousands of human
beings?
* * * * *
The second discovery which I shall mention is that of the infectiousness of
tuberculosis. Thousands and thousands of doctors had had tuberculous
patients under their care. Three thousand years ago, Hippocrates described
tuberculosis with as much precision as could be done to-day. Illustrious
physicians in every land had tried to analyse the nature of this terrible
disease and to unravel its cause; nevertheless, they were unable, from
clinical observation alone, to prove what is to-day quite commonplace
knowledge, viz., that tuberculosis is infectious. In 1864, a French doctor,
Villemin, conceived the simple and ingenious idea of inoculating rabbits
with the tuberculous matter found in the lungs of consumptive patients.
These rabbits became tuberculous; they died in a few weeks with tuberculous
granulations in lungs and liver. It was thus demonstrated that tuberculosis
was infectious. Later on, in 1878, Koch discovered that the active agent of
this infection is a special microbe. But, however important may be the
discovery of the microbe of tuberculosis (the tubercle-bacillus of Koch),
the essential dominating fact is that tuberculosis is infectious.
As soon as this great fact became known, a profound revolution occurred in
social hygiene, in the treatment and in the prevention of this terrible
evil. We know now the consumptive man carries in his lungs and sputum the
germ capable of developing the same evil in others; consequently we know
how to preserve ourselves against tuberculosis. We must purify or destroy
the habitations wherein consumptives have lived, burn or carbolise all the
sputum, make spitting in public places a punishable offence, take sanitary
measures against unhealthy meat, defend our children against contaminated
milk--in a word, we are armed against a disease, the sole and unique cause
of which, as experimentation alone has taught us, is infection.
Formerly it was believed that diseases were due to a sort of divine anger,
or, what amounts pretty much to the same thing, to certain imperceptible
epidemic exhalations stretching over whole populations, or attacking
isolated individuals, striking like an exterminating angel, as his fancy
chose, such or such an unhappy victim. A sort of will or caprice, governed
only by chance, was exercised in relation to this disease, and man was
powerless, because he was unarmed against chance. He did not even think of
it. He resigned himself to being ill, and waited for the disease, without
doing anything to fight against it, benumbed under a kind of Oriental
fatalism. The doctor shook his head, bore testimony to the evil, and
confined himself to prescribing inefficacious treatments which were only,
according to a celebrated saying, a long meditation on death.
But the times have changed; there is no longer any fatality in
tuberculosis; there is imprudence, there is error, there is vice, and,
specially, social vice. We may almost say that, if there are still
consumptives in our midst, it is because of our defective social
institutions. We leave innumerable populations steeped in misery, seven or
eight individuals living in the same infected hovel. In the slums of our
large cities, swarms of infants are to be found morally and materially
perverted by misery. Therefore, if consumption still exists, it is our own
fault; it is no longer as it was in olden times, when we knew not, because
_now_ we know. The plague can be battled with; and if it still has so much
power left, it is because we have not the courage to apply to public and
individual hygiene the treatment science has definitely shown us should be
applied. To foresee is to know; and now that we know, we must not forget
that it is to experimenters, and to experimenters alone, that we are
indebted for this great benefit.
Moreover, however imperfect our defence against tuberculosis may still be,
it is by no means _nil_; great progress has been made; the mortality has
decreased in a considerable proportion. During the last twenty-five years,
it has decreased by about 25 per cent., and notably in England, where the
laws of public hygiene, energetically upheld by the good sense of the
people, are strictly applied, the mortality has diminished by 50 per cent.
This is only a beginning, and the near future will bring about the complete
extermination of the disease.
Now, honestly, I ask if the rabbits which Villemin sacrificed weigh more in
the scales of universal progress, and even in public morality, than the
three millions of individuals who, by progress in hygiene, have been
preserved from an early and painful death. I estimate at a high price the
life and the sufferings of fifty rabbits, but, at the risk of appearing a
barbarian, I prefer, to these fifty rabbits, the three millions of young
people who have been saved by Villemin's discovery, and the millions which
it will still save.
All the more so, inasmuch as experimental studies on tuberculosis have not
only preserved men; they have also preserved animals. Thanks to Koch, there
is now a very simple way of recognising if an animal is or is not
tuberculous. Koch was able to extract from tubercle bacilli, a substance
which he has called _tuberculin_. At first he thought tuberculin cured the
disease; but this was an error. Subsequent experiments showed that
tuberculin exercised quite a different action to that of healing. It has
the property, when injected in small doses into a tuberculous animal, of
provoking an intense fever, whilst it produces no reaction whatsoever in a
normal animal. If, therefore, tuberculin is injected into every animal in
the cattle shed, we can feel sure--and this is impossible otherwise--that
such or such animals are tuberculous or healthy. All cows that show a rise
in temperature after an injection of tuberculin are tuberculous; the
others, on the contrary, are in good health.
Thus the sanitary inspection of stables and cattle-sheds can be carried out
thoroughly; and we are now able to protect not only men but also animals
from the disease of tuberculosis.
Such results could only have been obtained at the cost of many and
methodical experiments. Whatever may be the genius of anti-vivisectionists,
they would never have been able to imagine anything similar had they been
left to their own intellectual powers. It is not in the study that we are
able to discover this long series of unforeseen, extraordinary, almost
miraculous facts which laboratory experimentation has been able to find
out. Man, said Pascal, tires of conceiving sooner than Nature tires of
providing; and experimentation is man's method of interrogating Nature.
* * * * *
The third discovery which I shall take as an example demonstrating the
value of experimentation, is the history of _Serotherapy_. And I may be
permitted to dwell somewhat on this subject as I had the good fortune, in
1888, of making the decisive experiment which was the beginning of
serotherapy.
Whilst inoculating some rabbits and dogs with a microbe taken from pus
(_Staphylococcus pyosepticus_), I developed a certain disease both in the
rabbits and in the dogs. But the dogs did not die, whilst all the rabbits
died from the results of the inoculation. I thought then that, the cause of
that resistance being due to the difference of blood, I might be able to
make the rabbit refractory to the infection by injecting it with the blood
of a dog in normal health. The experiment succeeded. The rabbits which had
received the blood of the dog, when they were afterwards infected with the
staphylococcus, became very ill but did not die. Later on, I took, not the
blood of a dog in normal health, but the blood of a dog that had received
the infection of the staphylococcus and had recovered from that infection,
and I injected this blood into the rabbits. _Now the rabbits that received
the blood of the infected, healed dog had acquired complete immunity to
this form of microbe infection_: the principle of serotherapy was
discovered (5th Nov. 1888).
[Illustration: "L'ENFANT."
_In Musee du Luxembourg, Paris._
_facing p. 53._]
Since then, serotherapy has been applied, by Behring in Germany and by Roux
in France, to diphtheria (1892). These two savants showed that the blood of
animals, and especially of horses, that had been infected with diphtheria
and cured, could, when injected into patients attacked by diphtheria,
diminish, in an extraordinary proportion, the duration and intensity of the
disease. There is no other treatment for diphtheria to-day. A doctor is
guilty, and even criminal, if he does not use it, for the therapeutic
results of this treatment are marvellous.
I do not speak of clinical observation only. All those who have seen the
effects of one of these injections of serum on children down with
diphtheria are veritably stupefied at the resurrection which they witness
only a few minutes after the injection. The unfortunate child with his
purple face and convulsed limbs, scarcely breathing, comes back to fresh
life as soon as he has received the beneficent injection of serum. The
facts are so decisively clear that even if we have only seen them once we
can never again forget them. But I shall simply call the attention of my
readers to the following statistics, the result of more than 500,000
observations made in England, in the United States, in France, in Russia,
in Germany, in Italy, in Austria, in fact everywhere: the death-rate in
diphtheria before 1892 (for the serotherapic method took four years to
become known and practised) was 45 per cent. After 1892, this death-rate
fell to 12 per cent.[8] Consequently, out of every hundred patients
suffering from diphtheria, thirty are saved by the serotherapic treatment.
Let us stop for a moment to consider these figures, which seem mere
abstractions to those who have not reflected. At the present time, about
300,000 children per annum in France are attacked by diphtheria; that makes
4,500,000 from 1892 to 1907. The proportion of 30 per cent. is therefore
1,350,000. The number of children who have been saved in France alone by
serotherapy in fifteen years is therefore 1,350,000. Let us put it in round
numbers at one million only; this would be sufficient to justify the death
of the twenty-five dogs and the one hundred rabbits which I sacrificed, and
of the two hundred horses which Behring and Roux used for the preparation
of the anti-diphtheria serum. A million families in mourning, a million
hopes mowed down in the bud! Only fanatics would dare to say this weighs
for nought in the balance.
Moreover--and why should I not say it aloud?--this so-called humanity of
anti-vivisectionists seems to me the antithesis of humanity. To satisfy a
conception which they have forged out of a certain hazy ideal, they make
quick shrift of human life and suffering. A hundred weeping mothers, a
hundred unfortunate children with gaping throats, suffocating, gasping, the
death-rattle at hand--that is what these sensitive souls declare is nothing
beside one rabbit which has had to receive a little blood of a dog into its
abdomen! These philanthropists are creatures of a fixed idea! Let humanity
suffer, weep and die! What does that matter, provided that their fixed
idea, driven right up to the hilt of delirium, triumphs! After all, if they
persist in believing that the faint and uncertain suffering of a sick
rabbit is not worth the certain and excruciating suffering of a thousand
human creatures, I can say but one thing: I pity them from the very bottom
of my heart.
* * * * *
These examples--antisepsis, tuberculosis, and serotherapy--will suffice
perhaps to justify experimental pathology. There is now another
experimental science which I am going to try to justify also. This is
_Therapeutics_.
We are only able to learn the action of medicaments by studying the action
of poisons, for all medicaments in strong doses are poisonous. Now, to
understand a poison thoroughly, we must experiment with it on the animal.
Simpson administered chloroform to men only after Flourens had determined
its anaesthesic properties on animals. Liebreich, after he discovered
chloral, studied its physiological properties on animals, and only after
long and learned studies was he able to give it a place in human
therapeutics. At the present day, chloral is one of the most extensively
used medicines, one which has relieved innumerable patients. When I carried
out my research on chloralose, before studying its effects on myself, I
began by giving it to cats and fowls. I was ignorant of the degree of toxic
power of this new, still unknown substance, and, at the risk of appearing
very pusillanimous, I did not wish to begin on myself; I preferred trying
it on a fowl. Not that I estimate my life very highly, but after all,
however low an estimate I may place on my own life, I think it is worth
more than that of a fowl. Many other medicines have been thus experimented
with on animals before it was possible to ascertain their effects on man.
Kocher discovered cocaine, Knorr antipyrine; and these two admirable
medicines did not find their way into therapeutics until their mode of
action and their toxic power had been ascertained on animals.
In a word, the whole of present-day therapeutics has for foundation, not
only ancient clinical observation, which it would be supremely foolish to
disdain, but also the experiments of modern times, which it would be
equally foolish to proscribe.
Perhaps certain people imagine that there are no therapeutics, and that we
can replace by auto-suggestion, prayer, or hypnotisation, everything which
doctors generally use to cure or allay disease. It is difficult to reply to
such objections, because those who make them have never opened a work of
science nor seen a patient. They see things as they wish to see them. They
imagine that the exterior world is constructed according to their interior
vision, and they do not deign to come into contact with reality. They
believe that enthusiasm can supply the place of instruction, and that a
certain doubtful generosity can replace profound and patient study. They
maintain perhaps that chloral does not make one sleep, that salicylate of
soda does not alleviate rheumatic pains, that bromide of potassium does not
check attacks of epilepsy. Perhaps they will even continue to say so for a
long time to come. Let them talk; progress will be made without them.
_Les chiens aboient et la caravane passe._
FOOTNOTES:
[7] See footnote, p. 17.
[8] These statistics can be found in all technical works; and I refer those
who may be curious to study them in detail to the special memoirs and
excellent treatises on pathology which have been published in England,
France, and Germany.
See also appendix.