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

  • Sampson Gamgee
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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    eight minutes after this injection of tartar emetic, appearance of some nausea, or violent and simultaneous contraction of lower abdominal muscles and diaphragm. The whole intestine is removed in order to see the stomach well; the viscus follows, like a pendulum, the altern- ate movements of contraction and relaxation of the diaphragm; the stomach, which is tolerably distended, is the seat of slow, continuous contractions, which always commence at the same point, the pylorus. The contraction and relaxation of the lower abdominal muscles and diaphragm take place gradually and slowly. This partition yields little by little, but uninterruptedly, to the abdominal muscles; these act similarly with regard to the diaphragm, so that if we form a material idea of these respiratory powers, we can compare them to two machines always equidistant, and directed in the same course, each describing the half of a double cone, whose limited base of reciprocal excursion would be in the middle. When one of them is at the summit, the other is at the base, and vice versd; consequently, the action of the diaphragm increases in proportion as that of the abdominal muscles diminishes. These forces are therefore essentially respiratory. The one—the diaphragm—is active during inspiration; the other—the force generated by the abdominal muscles—is expiratory. Renewed, sud- den, violent, and simultaneous contractions of the diapliragm and abdo- minal muscles occur; the latter even appear to augment their action in proportion as the diaphragm relaxes; it is the nausea, or the mani- festation of the effort. No vomiting has occurred; finally, the ani- mal expires. From this account it appears that, on seeing violent efforts of the abdominal muscles and diaphragm of a horse, into whose veins tartar emetic had been injected, and from whose abdomen all the intestines had been removed through a large opening, MM. Leblanc and Mignon inferred that the emetic was producing its specific action by exciting efforts to evacuate the stomach through the oesophagus. No vomiting occurred, and therefore the experiment, primd facie, establishes,— firstly, that the horse makes efforts to vomit when potassio-tartrate of antimony is injected into the veins; secondly, that as those efforts are not followed by vomiting, there must be some mechanical impediment to the escape of matters through the cardia. Both these conclusions are erroneous; and they are so for the following reasons. The de- scription given of the movements of the abdominal muscles and dia- phragm, is not such as to prove beyond doubt that they were efforts to vomit. Confessing adhesion to the doctrine that the diaphragm takes an active part in vomiting, we deny that it does so by virtue of an insjriratory movement, and that, as it relaxes, the abdominal muscles make a sudden effort, as in forcible expiration. The act of vomiting is one sui generis, and not a respiratory act.^ Let any one try to simu- ' Since the terms in wliich M. Mignon has related his experiment may leave some doubt as to his idea of the nature of the movements in vomiting, it may be cleai-ed up by his ulterior exposition of that idea. Ce phenom6ne (le vomissement) commence aux derniers tennes de I'inspiration pour finir dans Vexpiration. C'est dans co dernier temps ou pendant le relachement du diaphragme qu'a lieu le rejet des rnatiferes sans aucun doute; mais c'est dans inspiration, ou par le fait d'lme violente et brusque contraction du diaphragm, aide de 1'action des muscles abdo- minaux, que I'estomac verse son trop-plein daus I'oesophage.—Op. cit., p. 244.
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