ACTION ON SACCHARINE AND AMYLACEOUS PRINCIPLES., 269 



converted into glucose. 1 This, however, he found to be only 

 temporary ; and in experiments in which half an ounce of 

 loaf-sugar was given to the animal after a twelve hours' fast, 

 unaltered cane-sugar remained in the stomach for from two 

 and a half to three hours. 



Experiments in artificial digestion have shown that cane- 

 sugar is transformed into glucose by the gastric juice very 

 slowly, the action of this fluid in no way differing from that 

 of very dilute acids. In the natural process of digestion, this 

 action may take place to a certain extent ; but it is not shown 

 to be constant or important, and we must look to intestinal 

 digestion for rapid and effective transformation of cane-sugar. 



The action of gastric juice, unmixed with saliva, upon 

 starch is entirely negative, as far as any transformation into 

 sugar is concerned. When the starch is enclosed in vegeta- 

 ble cells, it is set free by the action of the gastric juice/ upon 

 the nitrogenized parts. It has been found by Bernard that 

 raw starch, in the form of granules, becomes hydrated in 

 the stomach; and he attributes this action to the elevated 

 temperature and to the acidity of the contents of the organ. 2 

 This is not the form, however, in which starch is generally 

 taken by the human subject ; but when it is so taken, the 

 stomach evidently assists in preparing it for the more com- 

 plete processes of digestion which are to take place in the 

 small intestine. 



Cooked or hydrated starch, the form in which it exists in 

 bread, farinaceous preparations generally, and ordinary vege- 

 tables, is not affected by the pure gastric juice, and passes out 

 at the pylorus unchanged. It must be remembered, however, 

 that the gastric juice does not prevent a continuance of the 

 action induced by the saliva ; and experiments have shown 

 that gastric juice taken from the stomach, when it contains a 

 notable quantity of saliva, has, to a certain extent, the power 



1 DALTON, On the G-asiric Juice and its Office in Diyestiam. American Jour- 

 fial of the Medical Sciences, October, 1854, p. 319. 



' J BERNARD, Leco-m de Physiologie Experimentale, Paris, 1856, p. 401. 



