CHAP. II.] IS STARCH DIGESTED IN THE STOMACH ? 155 



The Changes which Adipose Tissue undergoes in the Stomach. 



Until lately the majority of authorities have held that the fatty 

 constituents of the food undergo no change in the stomach, although 

 their subsequent digestion in the small intestine is promoted by the 

 solution of the walls of the fat cells which occurs in the stomach, and 

 which liberates their fatty contents. 



It was stated by Dr Marcet, however, that a certain decom- 

 position of the neutral fats takes place in the stomach. In a recent 

 research Cash 1 has found that when dogs are fed upon perfectly 

 neutral fats, fatty acids are liberated in small quantities, and 

 that when the mucous membrane of the stomach is digested with 

 neutral fats, in the presence of dilute hydrochloric acid, fatty acids 

 are likewise liberated. The setting free of traces of fatty acids, if 

 it occurs, will aid the subsequent emulsionizing of the fats by the 

 bile and pancreatic juice. 



The Changes which Starch undergoes in the Stomach. 



In discussing the changes which starch undergoes in the stomach, 

 we have to consider, firstly whether the gastric juice possesses by 

 itself any action upon starch, and secondly to what extent the action 

 of the saliva upon starch continues in the stomach. 



Does the ^he saliva of many animals, e.g. the dog, is devoid 



gastric juice of diastatic properties. If a dog be fed upon a meal 

 alone possess of boiled starch and killed during digestion whilst the 

 any action ^ stomach still contains food, mere traces of sugar are 

 found, but the contents contain both soluble starch and 

 erythrodextrin (Briicke 2 ). Unboiled starch is unacted upon. 



The contents of the stomach of man fed upon a 

 actionofsa^va diet containing boiled starch always contain consider- 

 upon the able quantities of sugar, and the question arises, Were 



starchy con- these produced by the momentary action of saliva upon 

 stituents of starch during mastication and deglutition, or did the 



J co . ntinu _ conversion of sugar under the influence of saliva con- 

 in the stomach? . . , , T , . 11- 

 tmue in the stomach ? In endeavouring to solve this 



question, we have to bear in mind, firstly, that diastatic ferments do 

 exert their action upon starch in a fluid of feebly acid reaction, but 

 secondly, that that action is arrested so soon as the reaction becomes 

 strongly acid. It would therefore appear most likely that in the 

 early stages of gastric digestion, before the admixture with gastric 

 juice is complete and when the acidity of the gastric juice is com- 

 paratively feeble, the diastatic action of the saliva proceeds in the 

 stomach, whereas soon after, when the acid reaction has attained a 

 certain figure, diastatic action diminishes or even ceases altogether. 



1 Cash, Archivf. Anat. u. Physiologic, 1880. Physiol AbtheiL, p. 323. 



2 Briicke, Sitzungsber. d. Wiener Acad. 3 Abth. Vol. LXV. (1872.) 



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