An inquiry into the reasons why the horse rarely vomits / by Joseph Sampson Gamgee.

  • Gamgee, Sampson, 1828-1886.
Date:
[1852]
Catalogue details

Licence: Public Domain Mark

Credit: An inquiry into the reasons why the horse rarely vomits / by Joseph Sampson Gamgee. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    late the effort to vomit, or study the real effort in his own person, and he will feel that the glottis having been closed after a deep insjjira- tion, the diaphragm and abdominal muscles act simultaneously, so as to press the stomach between them. To this it may be objected that, for the diaphragm to descend while the glottis is closed, the air in the chest should be rarefied, which is an unlikely occurrence. The fallacy of this objection is demonstrable by experiment, as Dr. Sharpey has long since shown in his lectures on anatomy and physiology in University College. A bandage being closely passed round the lower part of the chest, it is easy to press down the diaphragm at will; on doing so, the bandage becomes loose, evidently owing to drawing in of the cartilages of the lower ribs by the descending diaphragm. Thus the augmentation of the thoracic cavity in its long axis, is comjiensated by its decrease in the transverse ; and it becomes obvious that the diaphragm may descend when the glottis is closed, without enlarging the chest, and therefore without rarifying the contained air. That, however, the witnessed efforts were in reality the pangs of death, is rendered more than probable by the terms in which the narrative of the experiment ends,— enjin, Vanimal expire.'^ ^ But conceding, for the sake of argument, that the movements ob- served were efforts to vomit, we maintain that it is not just to conclude that, because they were not followed by vomiting, there must have been some mechanical obstacle to the escape of matters through the cardia. As the experiment was performed, it was impossible for the stomach to be pressed upon by either the abdominal muscles or dia- phragm, and therefore there was no chance of its contents being eva- cuated through the oesophagus. Protected, as the horse's stomach is, by the far-back projecting ribs, it can only receive pressure from the abdominal muscles, indirectly, through the intestines. When these are removed, the viscus cannot be pressed upon by those muscles, and the pressure of the diaphragm on it is very slight, because the stomach undulates like a pendulum, backwards and forwards, in the empty cavity, Avithout meeting with the least resistance. The evidence which we have adduced, and which is all that w^e have been able to collect, in favour of the doctrine that efforts to vomit can be excited in the horse by injecting tartar emetic into its veins, may be thus briefly summed up :— 1. M. Lecoq and his colleagues (the veterinary professors of Lyons) have expressed an opinion in the affirmative, without publishing the grounds of their belief. 2. The experiment of MM. Leblanc and Mignon, which professes to prove the doctrine, appears to have been conducted with so little re- gard to the exclusion of sources of error, that it would be unwarrant- able to draw any positive inferences from it. 3. As we are not acquainted with the details of the experiments which formed the basis of M. Dupuy's statement in support of the above doctrine, they need confirmation; a need which becomes im- ' As the perforaiance of such experiments in horses renders it indispensahle that they should be thrown on the ground and secured, great caution should he observed in intei-preting the muscular efforts ; for when a horse is cast he strug- gles violently for liberty, even before a bold stroke of the knife has made a gash seven inches long into its belly, and all the bowels have been removed.