142 Institute of France. 



Compression is not sufficient of itself, however ; for, if we corrt- 

 press with our hands a stomach displaced as above in a dog into 

 whose veins no emetic has been injected, we can very well expel 

 its contents witliout producing thereby a true vomiting, because 

 there arc neither nauseae nor inspirations attending this kind of 

 connilsion : but if we pull the stomach instead of compressing 

 it, and il' we extend the pulling to the oesophagus, the nauseae 

 and all the other symptoms of vomiting appear, without there 

 being any occasion for ail emetic. Thus, vomiting would result 

 from the compression exercised on the stomach by a convulsive 

 contraction of the muscles which surround the belly ; and this 

 contraction itself may be excited by an irritation of tl-ie oeso- 

 phagus. 



It being of importance to know v/hat muscles chiefly acted, 

 what nerves put tliem in motion, and by what causes tliey were 

 irritated, M. iNIagcndie in the first place cut or removed the 

 abdominal muscles, without much diminishing the activity of 

 the vomiting : on the contrary, when we take from the dia- 

 phragm a great part of its strength by the section of the phrenic 

 nerves, there are nothing but small retchings at long intervals, 

 and the vomiting rarely takes place notwithstanding the abdo- 

 minal contractions. Thus, the part acted by the diaphragm in 

 this compression is by far the greatest. Wlien we thus destroy 

 at once the action of the diaphragm and that of the muscles, 

 the vomiting no longer takes place, even if we make the animal 

 swallow substances eminently and promptly emetic, such as 

 corrosive sublimate. Finally, and this seems to form an al- 

 most marvellous completion of all his experiments, M. Ma- 

 gendie entirely removed the stomach : he substituted for it a 

 bladder, which he attached permanently to the base of the 

 oesophagus, by making it communicate with this conduit by a 

 solid tube ; and after again sowing up the abdomen, he injected 

 some emetic into the veins : the animal had nauseae, made in- 

 spirations, and ejected a coloured liquid, (with which the bladder 

 had been partly filled,) quite as well as it could have done, if, 

 with a natural stomach, an emetic had been administered in 

 the common way. 



Thus, an emetic does not cause vomiting by irritating the fibres 

 of the stomach, nor even the nerves, but by acting by means 

 of absorption and cifL-ulation on the nervous system, and by ex- 

 citing an action which is reflected specifically on the oesophagus 

 and diaphragm, so as to m.ake them exert various movements, 

 among which there are some, tiie definitive result of which is 

 the compression of the stomach : this does not prevent there 

 being vomitings produced by the immediate irritation of the 

 nerves of some of tlmse parts, or by any given nervous irritation 



which 



