COMPOSITION OF GASTRIC FLUID. 2/5 



Composition of Gastric Juice. 



Human Sheep's Dog's 



Gastric Juice. Gastric Juice. Gastric Juiee. 

 Water . . . 994 '40 986' 14 97i'i7 



Solid Constituents . 5-59 13-85 28*82 



Ferment, Pepsin (with 



a trace of Ammonia) . 3 '19 4/20 I 7'5 



Hydrochloric Acid . O'2O 1-55 270 



Solids j Chloride of Calcium . 0*06 0*11 i'66 



Sodium . 1-46 4-36 3-14 



,, Potassium .0*55 1-51 1*07 

 Phosphate of Lime, 



Magnesia, and Iron .0-12 2*09 273 



In all the above analyses the amount of water given 

 must be reckoned as rather too much, inasmuch as a cer- 

 tain quantity of saliva was mixed with the gastric fluid. 

 The allowance, however, to be made on this account is 

 only very small. 



Considerable difference of opinion has existed concern- 

 ing the naturo of the free acid contained in the gastric 

 juice, chiefly whether it is hydrochloric or lactic. The 

 weight of evidence, however, is in favour of free hydro- 

 chloric acid, being that to which, in the human subject, the 

 acidity of the gastric fluid is mainly due ; although there 

 is no doubt that others, as lactic, acetic, butyric, are not 

 unfrequently to be found therein. 



The animal matter mentioned in the analysis of the gas- 

 tric fluid is named pepsin, from its power in the process 

 of digestion. It is an azotised substance, and is best pro- 

 cured by digesting portions of the mucous membrane of 

 the stomach in cold water, after they have been macerated 

 for some time in water at a temperature between 80 and 

 1 00 F. The warm water dissolves various substances as 

 well as some of the pepsin, but the cold water takes up 

 little else than pepsin, which, on evaporating the cold 



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