CHAP, xxiv.] VOMITING. 213 



pulsion of air from the lungs and keeps them in a certain state of 

 distension until the effort of vomiting is over, when the diaphragm 

 relaxes and complete expiration takes place. That there cannot be 

 complete closure of the glottis in the effort of vomiting is shown by 

 the fact, that that act is very frequently accompanied by a loud ex- 

 plosive noise which must be formed in an open, although a resisting 

 glottis. 



Dr. Anderson has shown by direct experiment that when dogs 

 vomit under the influence of tartar emetic, the diaphragm is forcibly 

 contracted. He introduced his finger into the abdomen, and found 

 that during each effort of vomiting the diaphragm became tense 

 and rigid, and descended towards the abdomen. And this he found 

 took place even when the trachea had been previously opened, 

 whence we may infer that the force of the expiratory muscles is 

 spent chiefly upon the stomach.* 



A warm controversy took place in the last century, and was 

 revived in the present, with reference to the share which the 

 stomach itself takes in the act of vomiting. Many high names in 

 physiology took part in this discussion, some maintaining, among 

 whom was John Hunter, and, subsequently, Majendie, that the 

 stomach was perfectly passive, and that the abdominal muscles and 

 the diaphragm were the sole agents of expulsion, while others, as 

 Haller, Rudolphi, etc., allowed that the contractions of these muscles 

 only assist the expulsive efforts of the stomach, which in some in- 

 stances may act independently of the surrounding muscles. Main- 

 gault affirmed that he had seen vomiting occur after the division of 

 the diaphragm and the abdominal muscles, and Rudolphi made the 

 same assertion. And the Committee of the French Academy ap- 

 pointed to investigate the question, admitted that it needed only a 

 very slight external pressure to produce vomiting, and that distinct 

 contractions of the muscular coat of the stomach were seen during 

 the act in the neighbourhood of the pylorus. The question is one 

 which cannot be decided by cruel experiments, unless it can be shown 

 in several instances that vomiting can take place under conditions 

 which render the abdominal muscles and diaphragm incapable of 

 acting ; such evidence would unequivocally demonstrate the activity 

 of the stomach. f But the opposite experiments, such as the non- 



* See Anderson, Lond. and Edin. Monthly Journal, 1844. In this paper, Dr. 

 Anderson has given a complete refutation of Dr. Marshall Hall's supposition 

 tbat the diaphragm is inactive in vomiting. 



t M. L'Epione records, in the Bulletin de 1' Academic de Medicine, a case in 

 point. A man's abdomen was torn open by a horn, and the stomach wholly 



