MANUAL OF CATTLE-FEEDING. 59 



tion is a complicated and a slow one, the animals should be 

 allowed the necessary time and repose to complete the act 

 of rumination undisturbed. 



G-astric Digestion. — In the fourth stomach of rumi- 

 nants and the simple stomach of other animals, the food is 

 subjected to the action of the gmtric juice. This fluid is 

 produced by innumerable small glands, imbedded in tlie 

 inner coat of the stomach, which, when excited by the pres- 

 ence of solid matter in the latter, pour out abundantly 

 a clear, colorless fluid, having a sour ta?ste and smell, and 

 containing two characteristic ingredients. 



One of these is mnnatlc aeid^ the chlorine of which 

 comes from the salt of the food ; the other iBj?€pmij an or- 

 ganic substance about whose composition and properties 

 little is known with certainty, but which acts powerfully, at 

 the temperature of the body, on the albuminoids of the 

 food. 



Its first effect on the soluble albuminoids is to coagulate 

 them. Afterward, however, the pepsin, in the presence of 

 the muriatic acid of the gastiic jtiice, acts on the coagulated 

 or the originally solid albuminoids, and converts them into 

 substances called j)ej)to?ies, having much the same proper- 

 ties as piotein, but soluble in water, and hence easily taken 

 up into the circulation. 



The formation of peptones from ajbnminoids seems to be accom- 

 plished by the assimilation by the latter of the elemenfcs of water, being 

 similar to the formation of dextrine and sugar from starch by the ac- 

 tion of acids or alkalies. Indeed, albumin, when treated with acids, 

 yields peptones- 



Accordmg- to Hoppe Seyler,* the chief action of pepsin consists in 

 this, that it unites with the muriatic acid present, transfers it to the 



4t i 



' Physiologische Chemie," 1878, p. 231. 



