DIGESTION. 601 



with muriatic or acetic acid, and kept at the temperature of 100, 

 solution takes place, and the gelatin loses its property of gela- 

 tinizing, and of being precipitated by chlorine. But these aci- 

 dulated liquids are incapable of dissolving coagulated albumen 

 or fibrin, and likewise to a certain extent casein. To make an 

 artificial juice capable of dissolving these very common articles 

 of food, a portion of the third and fourth stomachs of an ox 

 was digested for twenty- four hours in water, containing 2*75 per 

 cent, of muriatic acid. It contained in solution 2 '75 per cent, of 

 solid matter. A portion of this solid matter was pepsin. For 

 when the liquid thus prepared was digested for some hours on 

 coagulated albumen in powder, a complete solution was obtained. 



It would appear from the present knowledge possessed by phy- 

 siologists, that the gastric juice, besides salivin, contains a certain 

 quantity of muriatic acid and pepsin. This liquid, in conse- 

 quence of the temperature and the peristaltic motion of the sto- 

 mach, gradually dissolves the food into an opal -coloured and ad- 

 hesive liquid called chyme. 



The chyme thus formed passes into the duodenum, where it is 

 gradually separated into two distinct substances. 1. A milky 

 liquid, which is absorbed by the lacteals, under the name of 

 chyle, and a quantity of excrementitious matter, which gradually 

 makes its way along the intestinal canal, and at last is thrown out 

 of the body altogether. 



According to Leuret and Lassaigne, a portion of chyle is 

 formed in the stomach itself. They assure us that, if the stomach 

 of a living animal be opened during digestion, the white vessels 

 or lacteals of the stomach are easily seen. They inform us that 

 they have collected chyle from the lacteals in the stomach of the 

 horse, and ascertained by experiment that it possesses the usual 

 properties of that liquid.* 



These gentlemen affirm also that, if the duodenum of a living 

 animal be opened, and a stimulating substance, as vinegar, ap- 

 plied to its villous coat, a quantity of liquid is immediately se- 

 creted, similar in appearance to the gastric juice of the stomach.f 

 If this be a correct statement of facts, there can be little doubt 

 that the liquor given out by the villous coat of the duodenum 

 during digestion is destined to act upon the chyme, and to assist 



* Recherches surla Digestion, p. 124. f Ibid. p. 140. 



