Institute of Fr ante. 141 



the blood which clrjculated from the one to the other. In all 

 the expeiiments, convulsions and de.ith came on as promptly as 

 if the upas had been a])plied to the entire animal. Some how- 

 ever will still object, perhaps, that when the upas was introduced 

 into the intestine, it might alwavs be supposed that there re- 

 mained some concealed lymphatic vessel; that, when it was 

 applied to the foot, it was inserted into a wound, from which 

 it could penetrate into the blood by open veins and arteries; and 

 that this is by no means whnt is meant when we admit the 

 venous absorption, for in that case we mean an action attri- 

 buted to the veins in their natural state, and by their organic 

 pores. What is still more remarkable in the exj)eriinents of 

 Messrs. Magendie and Delille, is, that the blood of an animal 

 already poisoned, and ready to die, when transfused into the veins 

 of another animal, does not kill the latter, and scarcely occasions 

 to it any inconvenience. 



M. Magendie has made another very interesting application 

 of this action of certain substances, when introduced into the 

 blood. 



We know that an emetic injected into the veins of an animal 

 makes it vomit in a few minutes, v/hilst it recjuircs a whole liour 

 when an emetic is swallowed to produce the same effect: and we 

 instantly conclude, that this convulsive movement does not <le- 

 pend on the immediate action of this remedy on the coats of 

 tlie stomach. 'f)bservations made on the viscus itself, during the 

 operation of vomiting, have led some physiologists still further. 

 They perceived tliat the coats of the stomach underwent very 

 little agitation ; and hence thev concluded also, that it is not in 

 tlie irritation of these coats that tlie immediate cause resides of 

 the ex]iulsion of the contents of the stomach. Their ophiions, 

 however, were but feebly supported, and have almost fallen into 

 oblivion since Lieutaud and Haller introduced one directly con- 

 trary. 



M. Magendie, wishing to ascertain the truth, employed the 

 convenient method of injections; and having first made an open- 

 ing in the abdomen, lie ascertained by tlie touch, that during 

 vomiting the stomach itself remains in a state of inertia, but 

 that at every successive retching it is violently compressed by 

 the contractiou of the diaphragm and the muscles of the lower 

 beily : besides, the long inspirations which precede every vomit 

 introduce a sufficiency of air into the stomach to prevent its 

 capacity from diminishing, notwithstanding the quantity of 

 matter whicli it ejects. If we open the abdomen wide enough 

 to let out the stomach, the nause;e continue ; but they become 

 impotent, bccaase the muscles no longer compress the viscus : 

 when we repliice the stomachy the vomiting immediately begins. 



Compressio* 



