DIGESTION OF THE ALBUMINS. 187 



the intermediary products of digestion of different albumins are the 

 same, irrespective of their origin. Strictly speaking, this is probably 

 not correct, although in the absence of quantitative studies of their 

 decomposition-products it is scarcely warrantable to make positive 

 statements. Their identity, however, is rendered unlikely by the 

 varying degree to which the various primary radicles are represented 

 in the different native bodies. 



Digestion of the Proteids. 



The digestion of the nucleoproteids and nucleo-albumins, like 

 that of the native albumins, begins in the stomach. Here the sep- 

 aration of the non-albuminous pairing is first effected, and is then 

 followed by the digestion of the liberated albumins. This digestion 

 is in all respects analogous to that of the native albumins proper. 

 Syntonins are first formed, then primary albumoses, subsequently 

 secondary albumoses, and finally "peptones" i. e., bodies which still 

 give the biuret reaction, but which in contradistinction to the albu- 

 moses are not precipitated by salting with ammonium sulphate. 

 The individual products which thus result from the proteids have 

 not been studied with the same care as those which are derived 

 from the native albumins, but there can be no doubt that here also 

 Kiihne's schema of digestion does not apply in its original form. 

 Individual differences also probably exist between the various 

 digestive products according to their origin, but of these also we 

 know but little. 



Of special interest are the earlier phases of digestion of the 

 casein of milk. This normally exists in the milk in solution as a 

 neutral calcium salt. In the stomach a transformation into the 

 corresponding acid salt is then first effected by the hydrochloric 

 acid of the gastric juice, and followed by the action of the chymosin. 

 According to Hammarsten, this effects a partial decomposition of the 

 soluble acid salt with the formation of calcium-paracasein, and a 

 small amount of an albumose-like posset albumin. The paracasein 

 is then precipitated and decomposed, with the formation of the cor- 

 responding paranuclein and the albuminous pairling. 



Of the fate of the non-albuminous components of the proteids 

 but little is known. The paranuclein of casein, it is stated, undergoes 

 solution on continued digestion in vitro, but is at the same time de- 

 composed with the formation of a small amount of orthophosphoric 

 acid and an organic acid, which likewise contains phosphorus. Of 

 this, however, nothing further is known. 



The nucleins proper are not digested in the stomach and remain 

 undissolved. 



Under the influence of the pancreatic juice casein is digested in 

 very much the same manner as with the gastric juice, but in this 

 case the transformation into paracasein is brought about through 

 the influence of the chymosin of the pancreas in an alkaline medium. 



