1/4 PHYSIOLOGICAL CHEMISTRY. 



per cent of solids. Of the solids about 9 parts are organic 

 and i part inorganic. The organic matters are largely pro- 

 tein in character, while the phosphates and carbonates of the 

 alkali metals along with common salt are the important min- 

 eral constituents. The alkalinity is due to these phosphates 

 and carbonates. The following results have been given for 

 the composition of a human pancreatic fluid obtained from a 

 fistula : 



Water 864.05 per thousand. 



Organic solids 132.51 " 



Inorganic solids 3-44 



The protein amounted to 92 parts per thousand. 



Among the organic substances we have the enzymes, traces 

 of fat, soaps, leucine and other bodies in small amount. The 

 specific importance of these substances, aside from the en- 

 zymes, is not known. 



THE BEHAVIOR OF TRYPSIN. 



In an earlier chapter a few words were said about the func- 

 tion of this important pancreatic enzyme and it remains to 

 discuss its practical relations to food digestion. The acid 

 chyme from the stomach passing into the intestine is neutral- 

 ized by the alkaline pancreatic fluid and the bile. In this 

 neutralized condition the trypsin is able to continue the break- 

 ing down process begun by the pepsin, and the proteoses 

 formed in the stomach are carried further to the peptone stage 

 and made ready for absorption. From what was said in the 

 last chapter it is evident that the trypsin could effect the pre- 

 liminary changes also; that is, it is not really necessary that 

 the food proteins should be brought into the proteose condi- 

 tion before the action of trypsin may begin. This enzyme is 

 able to effect the complete digestion from the beginning, and 

 rather rapidly too, which may be illustrated by experiments, 

 using either the minced gland from some animal or an extract 

 made by the aid of a proper solvent. Such an active extract 



