CHYME. 37 



Tiedemann and Gmelin, appears to be partially converted into 

 albumen. 



4. Glutin becomes so changed by artificial digestion, that it 

 loses its property of gelatinizing, and can no longer be precipitated 

 by chlorine. 



5. Sugar of milk, when submitted for a sufficient time to the 

 action of pepsin, becomes completely converted into lactic acid. 

 This fact has been established by Fremy and myself. 



6. Starch is partially converted into sugar. (Tiedemann and 

 Gmelin.) 



7. The fluid found in the stomach of a horse, fed with oats, 

 contained butyric acid, a resin, a substance resembling extract 

 of flesh, salivary matter, and albumen. 



From recent experiments on digestion, we know that alimen- 

 tary substances are dissolved as rapidly in an artificial digestive 

 fluid, consisting of pepsin and properly diluted muriatic acid, as 

 they are in the gastric juice itself. Hence we are justified in 

 the conclusion that pepsin, the free acid, and a suitable tempe- 

 rature, are the principal agents in gastric digestion, and that 

 the motions of the stomach are chiefly with the view of pro- 

 moting the due admixture of the food with the secreted fluid, 

 and of propelling it towards the pylorus, through which it must 

 pass in order to enter the duodenum. It is impossible to state 

 with certainty whether the pepsin and free acids dissolve and 

 modify the food through a catalytic influence, or whether they 

 enter into any chemical combination with it, the products of 

 these combinations being the dissolved and changed matter. 

 If, however, the conversion of sugar of milk into lactic acid is 

 explained by the catalytic action of the pepsin, we may fairly 

 conclude that the pepsin exerts a similar influence on other 

 substances, if no facts to the contrary present themselves. 

 Hiinefeld is inclined to attribute considerable influence in di- 

 gestion to the ammoniacal salts of the gastric juice, in conse- 

 quence of having observed that under certain conditions fibrin 

 is readily soluble in the muriate or lactate of ammonia, especially 

 when free lactic acid is also present. 



The various articles of food are dissolved in the process of 

 digestion with different degrees of facility. Those which ap- 

 proximate most closely to the constituents of the chyle, obvi- 

 ously require the least modification, as, for instance, the fluid 



