DIGESTION AND ABSORPTION IN THE STOMACH. 785 



The preliminary digestion in the stomach is important as regards 

 the protein foods from several standpoints: First, in the matter of 

 mechanical preparation of the food and its discharge in convenient 

 quantities easily handled by the duodenum. Second, in the more 

 or less complete hydrolysis to peptones and proteoses, whereby 

 the subsequent action of the proteolytic enzymes of the intestine 

 must be greatly accelerated. Indeed, in some cases, this prelimi- 

 nary action of the pepsin-hydrochloric acid may be absolutely neces- 

 sary. Native proteins, such as serum-albumin, are not acted upon 

 by trypsin, but if submitted to pepsin-hydrochloric acid they are 

 quickly digested by this enzyme. These and other facts seem to 

 indicate that the peptic digestion is not so much an end in itself as a 

 preparation for subsequent intestinal digestion. The stomach, 

 therefore, may be removed without a fatal result. Several cases 

 are on record in which the stomach was practically removed by 

 surgical operation, the esophagus being stitched to the duodenum.* 

 The animals did well and seemed perfectly normal, although special 

 precautions were necessary in the matter of feeding. 



Absorption in the Stomach. In the stomach it is possible that 

 there may be absorption of the following substances : Water, salts ; 

 sugars and dextrins that may have been formed in salivary digestion 

 from starch, or that may have been eaten as such ; the proteoses and 

 peptones formed in the peptic digestion of proteins or albuminoids. 

 In addition, absorption of soluble or liquid substances drugs, 

 alcohol, etc., that have been swallowed may occur. It was formerly 

 assumed, without definite proof, that the stomach absorbs easily 

 such things as water, salts, sugars, and peptones. Actual experi- 

 ments, however, made, under conditions as nearly normal as possible, 

 show, upon the whole, that absorption does not take place readily 

 in the stomach certainly nothing like so easily as in the intestine. 

 The methods made use of in these experiments have varied, but the 

 most interesting results have been obtained by establishing a fistula 

 of the duodenum just beyond the pylorus, f After establishing this 

 fistula food may be given to the animal and the contents of the 

 stomach as they pass out through the pyloric opening may be 

 caught and examined. 



Water. Experiments of the character just described show that 

 water when taken alone is practically not absorbed at all in the 

 stomach. Von Mering's experiments especially show that as soon 

 as water is introduced into the stomach it begins to pass into the 



* Ludwig and Ogata, "Archiv f. Physiologie, " 1883, p. 89; Carvallo and 

 Pachon, "Archives de physiologic norm, et path.," 1894, p. 106. 



t Compare von Mering, "Verhandl. des Congresses f. innere Med.," 12, 

 471, 1893; Edkins, "Journal of Physiology," 13, 445, 1892; Brandl, "Zeit- 

 schrift f. Biologie," 29, 277, 1892; London, "Zeitschrift f. physiol. Chemie," 

 62, 446, 1909. 

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