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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    App. IV. which the latter observer arrived. He adds, however, some new and interesting faets. Thus, he found that if one or two slight blows on the side of the head are given to a guinea- pig they are sufficient to bring on an epileptiform attack, after which the animal again recovers its liveliness, or it remains heavy for some time and then exhibits a kind of rotatory movement, like those shown by Schiff to oecur in rabbits after lesion of the crus cerebri. If the animal survives the blows, a similar epileptigenic zone is created as in the guinea-pig treated on M. Brown- Sequard’s method by lesion of the medulla oblongata at certain points or section of the seiatic; and as in these last cases, the zone is near the angle of the lower jaw. Before the zone is well established, and four weeks are usually re- quired for this purpose, the animals betray the presence of some irritation at this part by frequently scratching it. After it is established slight punching will induce tonie and clonic spasms though the sensibility of the skin is here diminished. The rapidity with which the zone can be established may be increased hjr striking the animal’s head on successive days, and the excitability of the zone endures for a period varying from six weeks to six months. The condition is hereditary. M. Westphal set himself to ascer- tain the nature of the changes induced by the blow or blows. That the condition is not produced by any altera- tion in the integuments is shown by the circumstance that the fits oecur when the exposed skull is struck.—Lancet, No. 2,528, p. 195. Dr. Brown-Sequard has with great kindness related to me his more recent researches, and shown me the interesting little animal upon which he is now experimenting. I have therefore the pleasure of being able to speak of them de visu, and of adding some interesting details of the note which I sent you two weeks ago. If you remember I then mentioned that the professor’s recent researches were upon some of the effects of section of the sciatic nerve and injury to the corpora restiformia in guinea-pigs. A great number of the animals were shown to me in wluch the sciatic nerve had been severed, and in all the zone epilepto- ge'ne did exist. I mean one single spot by exeiting which the fit was immediately produced. Pinch wherever you like independently of that situation, and though the animal will not like it, and will scream more or less, there is nothing abnormal, but as soon as you excite the particular spot it goes into a fit. In this situation, which may be easily circumscribed, extending from the ear to the eye round below the jaw, and backwards to the shoulder-blade, there seems to be an obvious impairment of nutrition, the hair is much less abundant, parasitical animals are found there, &c., and besides sensibihty is considerably diminished. The fits produced are quite similar to those brought on by section of the lateral half of the spinal cord. Dr. Brown-Sequard showed me some animals in which the paw of the limb where the sciatic nerve had been divided was more or less injured. This, he observed, was not a spontaneous injury, which must be attributed, as had been thought to the division of the nerve. The dragging of the paralysed limb produced a shght abrasion, and as soon as there was a di’op of blood, the little animal set to gnawing the insensible extremity. It is also the case with rabbits. There must be, however, a drop of blood to excite the voracity of the animals. In some of them two of the claws of the feet, the two outer ones, animated by the great sciatie nerve, which alone is severed, had fallen off, while the remaining claw and middle one, animated by the little sciatic nerve, was unimpaired. By wrapping up the limb in a bag as soon as section of the sciatic nerve is performed the experimenter prevents any injury occurring. With regard to his other series of experiments, those in the corpora restiformia, the professor showed me a great number of guinea-pigs in which I could trace the effects of injury to that particular part of the nervous system. The ears of several guinea-pigs showed the appearances of dry grangrene. In some of the animals half of the ears had already fallen. The aspect jweduced by the solution of continuity along the edge of the ear is quite distinct from that of a bite. In a bite the little portion of the ear seems cleanly cut off, whereas in dry gangrene it appears to have crumbled off. I have noticed the remains of two or three hEemorrhagic clots which had formed on the ear. To conclude, I may just mention that Dr. Brown- Sequard was much surprised when some of the French journals stated that he had neglected to note the occasional occurrence of hsemorrlmge in the ears of insane people. ,The fact is that the very object of the illustrious experimpter in mentioning the phenomena which he observed in Guinea- pigs was to show that the haemorrhagic clot observed on the eai-s of mad patients, and concerning the etiology of which there is still much discussion, may he due to purely internal nervous causes, and not to external violence, his chief aim in every one of these experiments being their applieatipn to the pathology and therapeutics of the human species.—Lancet, No. 2,382, p. 586. Nothnagel employs a new method for the determination of the functions of the brain. His observations are made mostly on rabbits. An incision is made in the scalp; the skull is perforated with a needle. Through the canal thus formed in the bone a very small drop of a concen- trated solution of chromic acid is injected by means of a hypodermic spinge with a very slender nozzle. The scalp wound is then united by suture, and the animal does not seem to be affected, except with regard to the functional derangement incidental to the lesion. Generally they survive the operation two or three weeks, and die from causes which Nothnagel cannot explain, no constitutional symptoms being developed.—TAe Doctor, November 1st, 1873, pp. 214 and 215. Professor Nothnagel of Freiburg, contributes a paper to the last of Vichow’s Archiv Band, Ivii. (Heft. 2, p. 184), containing an account of a series of researches he has recently made in Heidenhaur’s laboratory upon the functions of the brain. With a few exceptions his ex- periments were made upon rabbits placed thoroughly under the influence of woorara. He acknowledges that dogs are better subjects for experiment, whilst their more convoluted brain resembles more closely than the rabbit that of man. On the other hand, rabbits can be obtained in any number, and they are not difficult to keep. The plan adopted by Professor Nothnagel, was suggested to him by Professor Heidenham and is somewhat peculiar. It consists in drilling a small hole through the cranium, through which the cannula of a subcutaneous injection syringe is inserted and plunged to a greater or less depth into the brain. A minute quantity, perhaps not amounting to more than quarter or half an ordinary drop, of a concentrated solution of chromic acid is then injected and the effects watched. The pain must be slight, as the animal often remains passive till the sutures requhed to close the wound are inserted. It is also obvious that in this mode of procedure bleeding and those alterations which might result from evaporation and exposure to cold are avoided. When the acid was injected directly into the ventricles, death took place in from ten to thirty minutes, the pulse becoming ver^ slow and great dyspnoea setting in, soon followed by increased action of the heart and convulsions. Similar experiments upon dogs, the acid being injected into the outer extremity of the gyrus postfrontalis, were attended with analogous results. .... When the animals lived for a fortnight or more they appeared to recover completely. .... Injection into the lenticular nucleus constantly produced the above described deviation of the limbs. Injection into the nucleus caudatus appeared for the first few minutes to be without effect, hut soon the animal began to leap forward, the leaps succeeding one another faster and faster till, after some minutes, it dropped exhausted upon its side, the limbs continuing to move rapidly.—Lancet, No. 2,601, p. 18. Nothnagel has continued his researches on this subject, still using the injection of chromic acid. When only one lenticular body was operated on the results were the follomng :—Deviation of the leg of the opposite side (right) towards the middle line and that of the same side (left) outwards, a lateral curvature of the spine with the convexity turned towards the opposite side (right) and at the same time a moderate cypposis. 4’he animal could, however, execute all voluntary movements. A different state of things occurred when lotn. micleilen- ticular is that operated on. In 26 cases the author succeeded with the operation, and the results in all cases coincided. The si)inal column was sometimes straight, sometimes cypnotic, but never curved laterally. The ears were erect and never laid backwards upon the neck. Respiration and action of the heart normal. If the fore limbs were care- fully extended so that the animal did not lose its equili- brium, and though the feet might be placed in a very unnatural position, as were the neck, they were not drawn back, as always occurs in the normal animal. Slight pinching of the tail, which a normal .animal would notice, was followed by withdrawal of the foot from the unnatural position, and the animal a])peared as if it would spring.