184 THE PROCESSES OF DIGESTION AND RESORPTION. 



The end-products of peptic digestion are qualitively the same as 

 those which result on tryptic digestion. The velocity of reaction in 

 the case of pepsin is, however, materially less than with trypsin. 

 On long-continued peptic digestion the following well-defined prod- 

 ucts have been obtained : leucin, amidovalerianic acid, tyrosin, 

 phenyl-alanin, glutarninic acid, asparaginic acid, cystin, lysin, ska- 

 tosin, putrescin, cadaverin, oxy-phenyl-ethylamin, but it is note- 

 worthy that during gastric digestion amino-acids are not formed. 



Among the products of digestion there must be mentioned the so- 

 called anti-albumid of Kiihne. This still bears an albuminous 

 character and supposedly contains the anti-group of the albuminous 

 molecule, as it is extremely resistant to the further action of pepsin 

 hydrochloric acid. On tryptic digestion it is thrown down as a 

 delicate jelly-like material the so-called anti-albumid coagulum. 

 The substance does not give Mi lion's reaction. 



As regards the extent to which peptic digestion is carried in the 

 stomach our knowledge is not complete. Zunz has recently studied 

 this subject in the case of dogs fed on meat. From these observa- 

 tions it appears that the coagulated albumins are first brought into 

 solution ; during this process very little acid albumin is formed, but 

 large amounts of albumoses appear, besides small amounts of pep- 

 tones and peptids. The larger portion of the material which is now 

 in solution then passes over into the small intestine, where it is 

 rapidly further decomposed and absorbed. A smaller fraction is 

 absorbed in the stomach directly, and here the more distant products 

 of digestion are primarily concerned, while an absorption of albu- 

 moses, though its occurrence cannot be denied, is nevertheless much 

 more difficult. Accordingly we find in the liquid contents of the 

 stomach mostly albumoses and only small amounts of the more re- 

 mote digestive products. Of albumoses, we find both primary and 

 secondary forms ; a definite relation between the two does not ap- 

 pear to exist. Peptones (according to the biuret reaction) are either 

 present in traces or they are absent, while peptids are constantly 

 encountered. 



As regards the appearance of the individual digestive products in 

 point of time and in relation to each other the following facts have 

 been ascertained (the observations have reference to crystallized serum- 

 albumin, crystallized egg-albumin, serum-globulin, euglobulin, 

 pseudoglobulin, and casein (Zunz). The solution of the coagulated 

 albumins begins at once after exposure to pepsin hydrochloric acid 

 at the temperature of the body. In the case of serum-albumin and 

 euglobulin the primary albumoses appear after nine minutes, together 

 with acid albumin. In the case of casein albumoses are likewise 

 found, but no acid albumin, at the same time. Pseudoglobulin and 

 egg-albumin appear to be more resistant, as no digestive products 

 can be demonstrated so early. Twenty-six minutes from the begin- 

 ning of digestion acid albumin and proto- and hetero-albumose can 

 be demonstrated in the case of the egg-albumin, together with the 

 deutero-albumose B. 



