ACTION UPON STARCHY AND SACCHARINE PRINCIPLES. 353 



As most of the saccharine principles of food exist in the 

 form of cane-sugar, it is the action of the digestive fluids 

 upon this variety of sugar which possesses the greatest phys- 

 iological interest. As cane-sugar passes from the stomach 

 into the duodenum, it is almost instantly transformed into 

 glucose. This fact has lately received additional confirmation 

 in the case of intestinal fistula observed by Busch. In this 

 case, when cane-sugar was introduced in quantity into the 

 stomach, fasting, the fluid which escaped from the upper end 

 of the intestine contained a small quantity of glucose, but 

 never any cane-sugar. 1 



It now becomes a question whether this transformation 

 into glucose is effected by the bile, the intestinal juice, or 

 the pancreatic juice. The pancreatic juice and the intestinal 

 juice are the two fluids which might be supposed to have this 

 effect ; as it has been repeatedly demonstrated that the bile 

 has of itself no direct action upon any of the alimentary 

 principles. 



This point is. settled by the experiments of Busch upon 

 the lower end of the intestine, in his case of fistula. Matters 

 introduced into this lower opening came in contact with the 

 intestinal juice only. He found that cane-sugar, exposed 

 thus to the action of the intestinal juice, was not converted 

 into glucose, but a large portion of it was found in the faeces. 

 These observations also indicate that cane-sugar is not read- 

 ily absorbed by the intestinal mucous membrane until it has 

 been transformed into glucose. 



Out of the body, the pancreatic juice is capable, if kept 

 but for a short time in contact with any of the saccharine 

 principles, of transforming them into lactic acid. Bouchar- 

 dat and Sandras believed that sugar was always changed 

 into lactic acid in digestion ; 2 but further experiments have 

 shown that this is not the case. 3 The contents of the small 

 intestine are sometimes alkaline or neutral, and sometimes 



1 Loc, cit. 2 Loc. cit. 



3 BERNARD, Memoire sur le Pancreas, Paris, 1856, p. 133. 

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