CONCERNING ANAESTHESIA IN VIVISECTION
A few words are first of all necessary to indicate precisely what
anaesthesia is.
By definition, an anaesthetic is a substance which, without paralysing the
activity of the heart and the respiration, abolishes sensibility. Indeed,
whenever general sensibility is abolished, there is, at the same time,
abolition of consciousness, of intelligence, and of memory. Another
characteristic of an anaesthetic is that its action is of a transient
nature. At the end of a certain time, it disappears; and then intelligence,
consciousness, and memory return gradually with sensibility.
It is well known that the admirable discovery of general anaesthesia,
allowing operations to be performed on man without the accompaniment of
pain, was due to chance. It was an American dentist, Horace Wells, and his
colleague, Morton (and others also perhaps), who discovered by chance that
protoxide of nitrogen (commonly called laughing gas) has the power, when
inhaled, of annulling all sensibility to pain for a certain length of
time--sufficiently long for a surgical operation (1840). Then they
discovered the effects of ether (1842). Since then, many other anaesthetics
have been introduced, notably chloroform, prepared by Soubeiran in 1832,
but the anaesthetic properties of which were only discovered in 1847 by
Flourens and Simpson; so that physiologists and surgeons are now quite
familiar with the mode of action of anaesthetics.
Anaesthetics, in appropriate doses, poison the nervous cells, which are the
seat of intelligence and sensibility, but leave unimpaired the functions of
the cardiac nervous system and of the nervous system governing the
respiration. An individual under chloroform breathes regularly; his heart
beats rhythmically, but all intelligence has disappeared; he has no longer
any will or memory or reflex actions, and the most painful operations can
be performed on him without provoking the smallest phenomenon of
sensibility.
Further, we have no hesitation in asserting that the anaesthetised animal
behaves like the anaesthetised man; that is to say, chloroform given to an
animal abolishes all sensibility to pain. Vivisection, therefore, on an
anaesthetised animal, does not provoke any pain. Physiologists are so
convinced of this that, however humane they may be, they have no scruple in
performing lengthy vivisections on an animal which is thoroughly
anaesthetised.
If chloroform, for some reason or other, cannot be employed, many other
anaesthetics, such as chloral and morphia, may be used. Chloral, in certain
doses, produces complete anaesthesia, and it is easier to administer than
chloroform. Formerly, chloral was injected, by a small puncture, into the
veins of rabbits and dogs. I pointed out another method which allows one to
avoid even the puncture; it is sufficient to make a rectal injection of the
solution of chloral. In two or three minutes, the dog, the rabbit, or the
guinea-pig, is seized with a kind of inebriety; he staggers, falls to the
ground, and in about ten minutes he is completely anaesthetised. Large doses
of morphia can be injected into animals without causing immediate death.
An animal under a moderate dose of morphia does not absolutely lose all
sensibility to pain; but the slight pain which he then feels is very
transient. If the animal is submitted to strong excitation, he wakens for a
few seconds, but soon falls back again into profound slumber. Morphia in
moderate doses is not such a perfect anaesthetic as chloral or chloroform;
it is therefore usual under such circumstances to administer also volatile
anaesthetics like chloroform, and quite small quantities of the latter will
then produce perfect anaesthesia. If, however, morphia is given in lethal
doses, as is sometimes done for comparatively short experiments, it is an
absolutely complete anaesthetic in itself, just as it is when a man takes a
fatal dose of morphia, or of its parent substance, opium.
Nevertheless, chloroform, chloral, and ether have a very serious
disadvantage for the physiologist. They abolish sensibility, but, at the
same time, they abolish the majority of the reflex actions in which
voluntary muscles are concerned. Now, in many experiments, it is
indispensable to be able to study such reflex movements, that is to say,
the fundamental reactions of the nervous system. Thus, physiologists, more
preoccupied, it must be said, with assuring the immobility than the
insensibility of the animal, have had recourse to another substance,
_curare_, the properties of which were investigated by Claude Bernard.
Curare is a poison which the natives on the banks of the Amazon prepare
from a bind-weed of the strychnia family. They boil the plant with several
ingredients, finally obtaining a sort of blackish resin, or gummy juice,
which they place in little gourds, which can be procured also in Europe.
This juice is used by South American Indians for their arrows, and
physiologists use it to ensure the immobility of the animal on which they
are experimenting. Curare dissolves in water, and a solution of a few
centigrams injected under the skin of a dog, a cat, a rabbit, will bring
about the death of the animal in a few minutes. But death is not due to the
arrest of the heart's action, it is due entirely to paralysis of the
respiration. Therefore the curarised animal can continue to live for
several hours if _artificial_ breathing be substituted for the natural
breathing which is paralysed. For several hours the animal is completely
motionless; the heart beats with force and regularity, provided that the
insufflation of air into the lungs introduces into the blood the quantity
of oxygen necessary for the life of the tissues. Now, under these
conditions, as Claude Bernard has so well demonstrated, we have no proof
that sensibility is abolished also. There is immobility; there is no true
anaesthesia. Take two animals, one chloroformed, the other curarised; both
are equally inert; but the chloroformed animal is insensible, whilst the
curarised animal retains sensibility.
It is impossible, therefore, to say that curare replaces anaesthetics,
because _curare is not an anaesthetic_.[6]
Now, in 1894 I was able to discover a substance which has all the
anaesthetic properties of chloroform, and which nevertheless does not
abolish reflex actions, so that physiologists are able to use it for
experiments which, formerly, necessitated the use of curare. This substance
is called _chloralose_; it is obtained by mixing anhydrous chloral with
glucose. It is not necessary for me to describe here in detail its chemical
or physiological properties; I will only say that in very small doses
(about twenty-five centigrams) it is an excellent hypnotic for man, and
that in larger doses, injected into the vein of a dog or a rabbit, it
brings about complete anaesthesia without affecting either the breathing,
the heart, or the reflex actions.
Since this discovery, many physiologists--and I regret not to be able to
say so of every physiologist--have given up curare and use nothing but
chloralose, which is a perfect anaesthetic, and which allows the reflex
actions to be studied although anaesthesia is perfect.
It may be objected that a tiny puncture has to be made in the vein to
introduce the chloralose into the circulation; but this puncture is really
such a trifle that it would be sheer childishness to pay any attention to
it. What doctor would hesitate to make a puncture in the skin of his
patient for the injection of a solution of morphia? However, if
sentimentality be pushed to such a degree as to shrink from touching the
vein of a dog in order to put him to sleep, even this tiny puncture can be
avoided by mixing the chloralose with the food of the animal to be
experimented upon. In half an hour or three-quarters of an hour after the
mixture is given he is in a state of perfect anaesthesia.
For these reasons, vivisection with anaesthesia seems to me to be quite
legitimate. As soon as it is recognised that man has the right to kill the
animal, he has the right to kill him as he pleases, provided he spares him
all suffering.
Let us also reflect a little on this point: an animal has to die just as
much as we ourselves. Now, natural death would certainly be for him a long
and cruel agony, lasting several hours, several days, perhaps several
weeks. Well, then, we replace hideous old age, the agony of prolonged
tortures due to disease, by a dreamless sleep, which at once plunges the
animal into nothingness, without his passing through the intermediary stage
of necessary suffering. Is this what is called being inhuman? For my part,
I shall regret on my death-bed that no physiologist will be found whose
conscience will permit him, or, if so, who would have sufficient courage to
help me to pass away under the influence of chloroform, ether, chloralose,
morphia, or chloral, thus saving me from the throes of the final struggle,
and bestowing upon me a peaceful death and an easy termination of all
suffering.
FOOTNOTES:
[6] In England, the Vivisection Act expressly states that curare is not to
be regarded as an anaesthetic, and this proviso has been loyally accepted by
English physiologists. On those rare occasions when curare is used, and the
occasions are very rare indeed, and year by year they become rarer, a
volatile anaesthetic such as chloroform or A.C.E. (alcohol, chloroform,
ether) mixture is administered at the same time in sufficient amount to
render anaesthesia absolute. One should add that since Claude Bernard's work
on curare, physiologists have seen reason for doubting whether it leaves
sensibility intact, as Bernard thought. But as there is doubt on the
question, and the available evidence in favour of its lulling sensations is
small, it is still considered advisable to retain Bernard's views, and act
as though it is not an anaesthetic at all.--(W. D. H.)