86 VOMITING. 



Vomiting cannot occur unless the stomach have the resistance of the diaphragm 

 and abdominal muscles, or of something in their stead. Above a century and 

 a half ago, enquirers began to make the horrid experiment of giving an emetic 

 to an animal, and, after the abdominal muscles were cut away, observing how 

 fruitless were all the efforts of the stomach to reject its contents till they ap- 

 plied their hands in place of these muscles, when, the stomach being forced by 

 the diaphragm against the resistance, vomiting was instantly accomplished. From 

 these experiments, Bayle, Chirac, Schwartz, Wepfer, &c. inferred that vomiting 

 could not occur without the assistance of the diaphragm and abdominal 

 muscles. Haller, Element. Physiol. lib. xix. xiv. Afterwards J. Hunter said, 

 " We know that the action of vomiting is performed entirely by the diaphragm 

 and abdominal muscles." On certain Parts, fyc. p. 199. Again, on the other hand, 

 Dr. Magendie finds that if the stomach is removed, and a pig's bladder sub- 

 stituted and connected with the oesophagus the retching induced by injecting 

 tartarized antimony into the veins, causes the diaphragm and abdominal muscles 

 to compress it sufficiently to expel its contents into the mouth. Memoire sur 

 le Vomissement, and Precis Elementaire. The division of the par vagum, which sup- 

 plies the stomach, was found by him, accordingly, not to prevent vomiting ; 

 whereas the division of the phrenic nerves, which supply the diaphragm, greatly 

 impedes it. 



But Dr. Haighton, one of those who have experimented on the sub- 

 ject, declares that the division of the par vagum did prevent vomiting in two 

 experiments which he made. (Memoirs of the Lond. Med. Society, vol. ii.) 

 Dr. Haighton observed the peristaltic action of the stomach to grow gradually 

 fainter as sickness continued, and at length to be inverted, although alone in- 

 sufficient to effect vomiting ; and he concluded that vomiting resulted from the 

 operation of the stomach on the one hand and of the abdominal muscles and 

 diaphragm on the other. He remarked that a quantity of air was swallowed 

 previously to the discharge, and the stomach is thus distended and brought more 

 under the influence of the diaphragm and abdominal muscles. 



* In vomiting, the muscles of the cavity of the abdomen act, in which is to be 

 included the diaphragm ; so that the capacity of the abdomen is lessened, and the 

 action of the diaphragm rather raises the ribs, and there is also an attempt to raise 

 them by their proper muscles, to make a kind of vacuum in the thorax, that the 

 oesophagus may be rather opened than shut, while the glottis is shut so as to let no 

 air into the lungs. The muscles of the throat and fauces act to dilate the fauces, 

 which is easily felt by the hand, making there a vacuum, or what is commonly 

 called a suction." J. Hunter, Observations on certain Parts of the Animal 

 Economy- 



It is generally accompanied by more or less of a peculiar sensation in the sto- 

 mach, called nausea. This frequently exists alone, and sometimes in a high degree; 

 but where it increases to a certain amount, it usually ends in vomiting. During 

 nausea the pulse is small, the temperature low, the face pale, and the head giddy, 

 and a large quantity of fluid is secreted in the mouth and fauces. It is excited by dis- 

 gust, certain articles, pain, sympathy of the stomach with other organs not in health, 

 by general derangement or disease of the stomach, by turning round, swinging, 

 or the motion of a ship, and from the latter cause takes its name, wvs (a 

 ship). 



