VOMITING. 631 



unsatisfied with the results of previous observations, appointed M. 

 Duverney 1 to examine into the question, experimentally and otherwise; 

 who, although he did not adopt the whole theory of Chirac confirmed 

 the accuracy of the facts on which it rested. He demonstrated, that 

 the stomach is but little concerned in the act ; and that it is chiefly depend- 

 ent upon the contraction of the diaphragm and abdominal muscles, which 

 enclose the stomach as in a press, so that its contents are compelled to 

 return by the oesophagus. On the other hand, in 1771, M. Portal, 2 in 

 his lectures at the College of France, endeavoured to show, that the 

 stomach is the great agent. He administered to two dogs arsenic and 

 nux vomica, which produced vomiting. The abdomen was immediately 

 opened; and, according to Portal, the contractile movements of the sto- 

 mach could be both seen and felt; and it was noticed, that instead of the 

 vomiting being dependent upon the pressure of the diaphragm on the 

 stomach, it occurred at the time of expiration; and was arrested during 

 inspiration, because the depressed diaphragm then closes the inferior 

 extremity of the oesophagus with such strength, that the contents can- 

 not be forced into the oesophagus when we press upon the organ with 

 both hands. The views of Portal were confirmed by the experiments 

 of Dr. Haighton. 3 He opened several animals during the efforts of 

 vomiting; and states that he distinctly saw the contractions of the 

 stomach. 



In more recent times, the physiological world has been again agitated 

 with this question. In 1813, M. Magendie 4 presented to the French 

 Institute the results of a series of experiments on dogs and cats, 

 animals, that vomit with facility. Six grains of tartrate of antimony 

 and potassa were given to a dog, and, when he became affected with 

 nausea, the linea alba was divided, and the finger introduced into the 

 abdomen to detect the state of the stomach. No contraction was felt ; 

 the organ appeared simply pressed upon by the liver and intestines 

 crowded upon it by the contracted diaphragm and abdominal muscles. 

 Nor was any contraction of the stomach perceptible to the eye; on the 

 contrary, it appeared full of air, and three times its usual size. The 

 air manifestly came from the oesophagus, as a ligature, applied round 

 the cardia, completely shut it off. From this experiment, M. Magendie 

 inferred, that the stomach is passive in vomiting. A solution of four 

 grains of tartrate of antimony and potassa in two ounces of water was 

 injected into the veins of a dog; and, as soon as nausea took place, an 

 incision was made into the abdomen, and the stomach drawn out of the 

 cavity. Although the retching continued, the viscus remained immova- 

 ble ; and the efforts were vain. If, on the other hand, the anterior and 

 posterior surfaces of the stomach were pressed upon by the hands, 

 vomiting occurred, even when no tartrate was administered, the pres- 

 sure provoking the contraction of the diaphragm and abdominal muscles, 

 and thus exhibiting the close sympathetic connexion, existing between 

 those acts. A slight pull at the oesophagus was attended with a similar 



1 Memoir de l'Acadm. pour 1700, Hist., p. 27. 



2 Cours d' Anatomic Medicale, Paris, 1804. 



3 Memoirs of the Lond. Med. Society, vol. ii. 



4 Memoire sur le Vomissement, Paris, 1813; and Precis Elementaire, edit, cit., ii. 152. 



