DIGESTION IX THE STOMACH. 483 



upon the pyloric sphincter. The proteins combine with the hydrochloric acid 

 and hence its action upon the sphincter becomes weaker, while this is not the 

 case with the carbohydrates. If the carbohydrates are moistened with alkali 

 they leave the stomach more slowly than usual, and the acid proteins, on the con- 

 trary, leave the stomach earlier than other proteins. 



As our knowledge of the digestibility of the different foods in the 

 stomach is slight and uncertain, so also our knowledge of the action of 

 other bodies, such as alcoholic drinks, bitter principles, spices, etc., on 

 the natural digestion is very uncertain and imperfect. The difficulties 

 which stand in the way of this kind of investigation are very great, and 

 therefore the results obtained thus far are often ambiguous or conflict 

 with each other. For example, certain investigators have observed that 

 small quantities of alcohol or alcoholic drinks do not prevent but rather 

 facilitate digestion; others observed only a disturbing action, while 

 still others report having found that the alcohol first acts somewhat as 

 a disturbing agent, but afterward, when it is absorbed, produces and abun- 

 dant secretion of gastric juice, and thereby facilitates digestion. The 

 accelerating action of alcohol upon the flow of gastric juice has been 

 mentioned on page 464. 



In regard to the importance of the stomach we used to be of the 

 general opinion that an abundant peptonization of protein does not 

 occur in the stomach, and that the food rich in protein is only 

 chiefly prepared in the stomach for the real digestion in the intestine. 

 That the stomach, at least the fundus, acts in the first place as a storage 

 chamber, follows from the shape of this organ, especially in certain 

 animals, and this function becomes especially prominent in certain riew- 

 born animals, as dogs and cats. In these animals the gastric secretion 

 contains acid but no pepsin, and the casein of the milk is precipitated 

 by the acid alone as solid lumps or as a solid coagulum filling the 

 stomach. Gradually small quantities of this coagulum pass into the 

 intestine and an overburdening of the intestine is thus prevented. In 

 other animals, as the snake and certain fishes which swallow entire animals, 

 the major part of the digestive work goes on in the stomach. The 

 importance of the stomach for digestion cannot therefore be established 

 in all instances. It varies in different animals and differs even in indi- 

 vidual animals of the same species, depending upon the fineness or coarse- 

 ness of the food, upon the greater or less rapidity with which pepton- 

 ization takes place, and also upon the rapid or slow increment in the 

 quantity of hydrochloric acid, etc. 



In regard to the extent of chemical digestive work, i.e., in the first 

 place the destruction of protein in the stomach, we have numerous 

 researches, some carried out by the use of older methods and others 

 by using newer and more reliable methods. Among these latter we 

 must mention those of ZUNZ, LONDON and collaborators, TOBLER, LANG 



