224 Agricultural Chemistry. 



secreted by the mucus membrane of the intestine. These two 

 enzymes are powerful agents and under their combined action 

 the proteins are reduced, in part at least, to simple fragments, 

 the amino-acids. 



The fatty foods undergo little or no alteration until they reach 

 the intestine. While in the stomach they become liquid from 

 the heat of the body and the neutral fat is liberated from the 

 cell structures by the action of the gastric juice. Most of the 

 neutral fats must be decomposed into the fatty acids and gly- 

 cerine, of which they are composed, before absorption into the 

 blood can take place. Under the influence of the fat splitting 

 enzyme of the pancreative juice, lipase, and the bile salts, the 

 neutral fats are partly decomposed, with formation of soaps. 

 These soaps aid in the formation of an emulsion of the rest of 

 the fats. Such an emulsion is really a suspension of the fat in 

 a very finely divided condition. Soap, free acid and glycerine 

 are then absorbed from the intestine and are found again com- 

 bined in the lymph as neutral fat. In this way the fats are ren- 

 dered available for the nourishment of the body. 



The transformation of starch into maltose is again taken up 

 by the amylopsin of the pancreatic juice. The maltose is further 

 exposed to an enzyme of the intestinal juice, termed maltose, 

 and decomposed into the simple sugar, dextrose. Other carbo- 

 hydrates, as the lactose of milk, and cane sugar, meet with special 

 enzymes in the intestinal juice, capable of converting them into 

 simple sugars, the final form in which the carbohydrates are 

 absorbed. 



No special enzymes fermenting the celluloses and pentosans, 

 which constitute a large proportion of hays and straws, have as 

 yet been prepared from the normal secretions of the intestinal 

 tract. Possibly their partial solution is effected by bacterial fer- 

 ments and other low forms of life. Such solution may have its 

 beginning in the paunch, where active fermentations are in 

 progress, and continue in the lower portions of the digestive tract. 



