COMPOSITION OF THE GASTRIC JUICE. 233 



ters by filtration, is a clear fluid, of a faint yellowish or 

 amber tint, and possessing little or no viscidity* Its reac- 

 tion is always strongly acid ; and it is now a well established 

 fact that any fluid, secreted by the mucous membrane of the 

 stomach, which is either alkaline or neutral, is not the nor- 

 mal gastric juice. 1 



The specific gravity of the gastric juice in the case of St. 

 Martin, according to the observations of Beaumont and Sil- 

 liman, was one thousand and five; 3 but later, Dr. F. Gr. 

 Smith found it in one instance, one thousand and eight, and 

 in another one thousand and nine. 3 There is every reason 

 to suppose that the fluid, in the case of St. Martin, was per- 

 fectly normal, and from one thousand and five to one thou- 

 sand and nine may be taken as the range of the specific grav- 

 ity of the gastric juice in the human subject. There is un- 

 doubtedly considerable variation as regards specific gravity 

 in the inferior animals. In the dog, it has been usually 

 found by Dalton as high as one thousand and ten. 4 



The gastric juice is described by Beaumont as inodorous, 

 when taken directly from the stomach ; but it has rather 

 an aromatic and a not disagreeable odor when it has been 

 kept for some time. It is a little saltish, and its taste is sim- 

 ilar to " thin, mucilaginous water slightly acidulated with 

 muriatic acid." 5 The gastric juice from the dog has some- 

 thing of the odor peculiar to this animal. 



It has been found by Beaumont, in the case of the human 



1 As the gastric juice of the dog is the fluid generally used in experiments, 

 it is proper to state that its reaction is always more strongly acid than the fluid 

 from the human subject. It is unnecessary to discuss the opinions of physiolo- 

 gists anterior to the time of Beaumont, who disputed with regard to the reaction 

 of the solvent fluid of the stomach, as they had no means of deciding what was 

 the true gastric juice. 



2 BEAUMONT, Observations, etc., p. 81. 



3 F. G. SMITH, Experiences sur la Digestion. Journal de la Physiologic, Paris, 

 1858, tome i., pp. 149, 152. 



4 DALTON, On the Gastric Juice, and its Office in Digestion. American Jour- 

 nal of the Medical Sciences, October, 1854, p. 315. 



5 Op. cit., p. 85. 



