328 DIGESTION. 



what contradictory. All observers, however, are agreed that 

 this fluid is more or less active in transforming starch into 

 sugar. But we must turn finally to the observations of 

 Busch on the case of intestinal fistula in the human subject 

 for the most satisfactory and definite information on this sub- 

 ject. In many points, it is true, these observations simply 

 confirm those which have been made upon the inferior ani- 

 mals, but they are of great value, as they establish conclu- 

 sively many important facts regarding the action of the 

 intestinal juice in the human subject. 



In this case, starch, both raw and hydrated, when intro- 

 duced into the lower opening, where it came in contact only 

 with the intestinal juice, was invariably changed into glu- 

 cose. Cane-sugar was not transformed into glucose, but ap- 

 peared in the faeces as cane-sugar. This is important, with 

 reference both to the want of action of the intestinal -juice 

 upon cane-sugar, and the fact that cane-sugar, as such, is not 

 absorbed in quantity by the intestinal mucous membrane. 



Coagulated albumen and cooked meat were always more 

 or less digested by the intestinal juice. This fact coincides 

 with the observations of Bidder and Schmidt. 



The observations which were made on fats, melted but- 

 ter, and cod-liver oil, showed that the pure intestinal juice 

 had little or no action upon them. These substances always 

 appeared in the faeces unchanged. "When, however, fatty 

 matters were taken into the stomach, they were discharged 

 from the upper opening in the intestine in the form of a very 

 fine emulsion, and could not be recognized as fat. 



It is evident from these facts that the intestinal juice is 

 important in digestion, more as a fluid which aids the gen- 

 eral process as it takes place in the small intestine, than as 

 one which has a peculiar action upon any distinct class or 

 classes of alimentary principles. It undoubtedly assists in 

 completing the digestion of albuminoid substances and in 

 transforming starch into sugar. Although, in the latter 

 process, its action is very marked, the same property belongs 



