304 DIGESTION. 



to dilate the cardiac opening of the stomach, and counteract 

 the contraction of the pillars of the diaphragm. 



It has been found "by Magendie that' during the nausea 

 which precedes the act of vomiting, there is always distension 

 of the stomach from deglutition of air. 1 This may be some- 

 times absent in the human subject, when vomiting occurs 

 very suddenly ; but in all Magendie's experiments upon ani- 

 mals, he found that immediately after an act of vomiting, 

 the stomach was flaccid, but that when another effort was ap- 

 proaching, and during the nausea which preceded, the organ 

 became gradually distended. Distension of the stomach 

 from deglutition of air previous to the act of vomiting was 

 observed in the case of extrusion of the stomach reported by 

 Lepine. 2 It is unnecessary to repeat the observations by 

 which it was shown that the air enters by the oesophagus ; 

 as they have already been referred to under the head of deg- 

 lutition. 3 



Summary. The symptoms which precede the act of 

 vomiting are sufficiently familiar. Usually they commence 

 with a peculiar sensation of depression and general malaise, 

 known as nausea. This is frequently accompanied by slight 

 pain in the region of the epigastrium, feeble pulse, cold and 

 clammy perspiration, and pallor. There is also usually an 

 increase in the flow of saliva. Retchings and the peculiar 

 acts by which air is forced into the stomach are frequent, 

 and immediately before the vomiting takes place, there is 

 generally a violent inspiration, followed by spasmodic closure 

 of the glottis. Yiolent and convulsive expulsion of a part^ 

 or the whole of the contents of the stomach by the mouth, 

 which is widely opened, then takes place. This is accom- 

 plished by spasmodic contractions of the diaphragm, the 



1 MAGENDIE, Memoire sur la Deglutition de I 1 Air atmospherique, lu d Vlnsti- 

 tut, le 26 octobre, 1813, p. 4. 



2 LEPINE, loc. cit., p. 149. 

 8 See page 207. 



