Report of the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes : with minutes of evidence and appendix.

  • Great Britain. Royal Commission on Vivisection
Date:
1876
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Licence: Public Domain Mark

Credit: Report of the Royal Commission on the practice of subjecting live animals to experiments for scientific purposes : with minutes of evidence and appendix. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    of the par vagum, we find that respiration continues almost normal. If now we cut away the part of the medulla giving origin to this pair of nerves, we find in most cases that respiration is suddenly stopped In weak animals after rriany parts of the encephalon have been taken away, the whole of the medulla oblongata and of the pons Varolii remaining, respiration sometimes continues normal, but it suddenly stops after a small part of the pons is removed. . . . . The stronger an animal is the more parts of its ence- phalon can be taken away before we destroy respiration. of the auditory nerve causes rolling, just as after the irritation of the processus cerebelli ad pontem; violent convulsions then occur in the eyes, the face, and m.any muscles of the neck and chest. The doctrine that the nerves of the higher senses are not endowed with general sensibility (j.e., are not able to cause pain) seems not to be true with regard to the acoustic nerve ; at least, the signs of pain given after an irritation of this pretended nerve are often as great as those observed after an irritation of the trunk of the trigeminal nerve.—Idem, Lancet, No. 1,842, p. 625. App. IV. In the strongest animals death occurs in a few hours, and from insufficiency of respiration, after the ablation of the encephalon except the whole of the medulla oblongata, and so it often is with anencephalic monsters. A series of experiments on pigeons has given me the following results; with the spinal cord alone respiration continues a few minutes, with the spinal cord and the part of the oblong medulla giving origin to the principal excitors of respiration, the vagi, this function continues many hours (the longest duration we have seen is thirteen hours), if there is also a great part of the base of the encephalon left respiration continues longer but I have never seen it last more than a day and a half. It seems indeed wonderful to see animals sometimes after a slight puncture of some part of the encephalon with the point of a needle, turn round, just like a horse in a circus, or roll over and over for hours and sometimes for days, with hut short interruptions. . Parts jiroducing turning or rolling after an injury on the right side. Turning or rolling by the right side. 1. Anterior part of the optic thalamus (Schiff). 2. The hind parts of the crus cerebri (Schiff). 3. The tubercula quadri- gemina (Flourens). 4. Posterior part of the processus cerebelli ad pon- tem (Magendie). 5. Place of insertion of the auditory and of the fa- cial nerves (Brown-Sequard and Martin-Magron). 6. Neighbourhood of the insertion of the lower roots of the par vagum (Brown- Sequard). While rotation takes place it is easy to ascertain, 1st, that jt is not its production by contractions resembling those of voluntary movements which causes the rolling or the turning; 2nd, that some muscles are in a state of tonic contraction; 3rd, that the trunk and neck of the animal are bent by a spasmodic action on the side of turning if it has a circus movement, and that it is bent like a corkscrew, as much as the bones allow, in cases of rolling; 4th, that sensibility and volition may remain, and there are frequent efforts to resist the tendency to turn or roll. And now, to add to the strangeness of the fact, in this last case the muscles remain contracted sometimes for hours, sometimes for days and weeks.—Idem, Lancet, No. 1,841, pp. 599, 600, 601. Turning or rolling by the left side. 1. Posterior part of the optic thalamus (Schiff). 2. Some parts of the crus cerebri near the optic thala- mus (Brown-Sequard). 3. Anterior and .superior parts of the pons Varolii. 4. Anterior part of the processus cerebelli ad pon- tem (Lafargue). 5. Place of insertion of the glosso pharyngeal nerve (Brown-Sequard). 6. Spinal cord, near ob- long medulla (Brown- Sequard). M. Flourens has found that the section of the semi- circular canals, in certain animals, is followed by a strange disorder of movements, and sometimes by a rotation (circus movement). I have ascertained that the phenomena ob- served in these experiments do not depend on the section of these canals, as this operation may not cause these phenomena, but that they are the results of an irritation of the auditory nerve, from the drawing upon it by the membranous semicircular canals at the time we divide them. In frogs and in mammals the direct irritation of the auditory nerve is followed by the most interesting ])henomena. It is well known that in frogs the peripheric extremity of this nerve is enclosed in a bag containing carbonate of lime; as soon as this bag is laid bare and slightly touched, and still more if it be punctured wth a needle or a bistonry, the anterior limb, on the opposite side, is thrown into a state of slight corivulsion, and kept almost constantly in a spasmodic pronation, and almost at every attempt to move forwards the animal turns round on the side injured. As long as it lives (many days, or even many months) these phenomena may be observed, although not quite so marked as immediately after the injury or after the first 24 hours. In mammals the least puncture I have now to speak of the condition of animal heat in cases of alteration of the spinal cord and the encephalon. The following conclusions may be drawn from a great many facts bearing on the subject : 1st, that usually anaesthesia is accompanied by a diminution of temperature : 2nd, that hyperaesthesia almost always co-exists with increased temperature; 3rd, that in paralysis, without either a notable hyperaesthesia or anaesthesia, the tem- perature is nearly normal. I must remark that the state of heat of a part is due to the amount of blood, the degree of heat of this fluid, the exposure of the part to the influence of the temperature of the surrounding medium, and the temperature of this medium.—Idem, Lancet, No. 1,843, p. 652, Professor Brown-Sequard is continuing with indefatigable labour the series of his valuable researches and exi)eriments upon the physiological pathology of the nervous system. His communications to the Academy of Medicine have formed the most marked features of the recent sittings of this learned society. As you will doulrtless give full atten- tion to these researches when they shall have been published in extenso, I shall only mention a few points thereof so as to keep you au courant of everything that crops up here at the very moment of the event. My letters must be photo- graphs of the passing occurrences of the day. M. Brown- JSequard’s most recent researches bear upon the consequences produced by certain lessons of the corpora restiformia and the sciatic nerve in guinea-pigs. According to the illus- trious experimenter, when the sciatic nerve is severed in guinea-])igs on e.xciting a certain determinate part of the face which he names le zone epile])togene epileptiform phenomena are produced. Excitement of no other portion of the face can induce an attack of epilepsy. But in order that the phenomena may take place, it is necessary that the excitement should be produced on the side corresponding to the limb where the nerve has been divided. M. Brown- Sequard showed two guinea-pigs to the Academy and re- produced his experiments before the assembly. M. Colin, one of the members, mentioned that he had often performed the division of the sciatic nerve without being able to induce epileptiform attacks. M. Brown-Sequard’s experiments on the restiform bodies are equally interesting and curious. One of the results of injury to the corpora is the production of haemorrhage under the skin of the ear. Hitherto certain kinds of haemorrhage had been observed as the result of injury to the nervous system, for instance haemorrhage of the kidneys in diseases of the spinal cord and haemorrhage of the intes- tinal tube in diseases of the brain. But the fact now illustrated is remarkable on account of its constant occur- rence. Another result is the production of dry gangrene of the ear, which, according to the experimenter, is not the consequence of paralysis produced by the section of the restiform bodies. M. Brown-Sequard exhibited a guinea- pig showing this kind of gangrene. At the last meeting of the Academy he again adverted to the subject, and stated that the precise point of the restiform body which he excited in order to produce ha?morrhage and sphacelus was the nib of the calamus scriptorius. Some particulars he added tended to show that this situation was really the one which he excited in his experiments, for instance, the paralysis of the tongue and anaesthesia of the lips—the animal could not hold the food which was introduced into its mouth. It was a well known fact that tlie hypoglassal nerve and fifth pair take their origin in the neighbourhood of the calamus scriptorius. M. Brown-Sequard concluded by pointing out the strict analogy which exists in a great number of cases between the phenomena determined expe- rimentally in animals and those which are observed clinically in man. On account of the extreme interest of these expe- riments M. Bouillaud has requested M. Brown-Sequard to repeat his experiments before a certain number of the members, which has been assented to.—-Lancet, No. 2,3801 p. 514. In the course of some recent experiments on the esta- blishment of artificial epilepsy in guinea-pigs. Dr. C. W est- phal has been over the same ground as that explored by M. Brown-Sequard, and fully corroborates the results at