DIGESTION OF THE ALBUMINS. 



171 



peptone-A. For the present we shall speak of this also as peptone B. 

 According to the above considerations, we may possibly represent 

 the process of peptic digestion by the following schema, which, how- 

 ever, is only provisional, and merely represents the facts as just 

 outlined : 



Native albumin 



Syntonin 



Proto-albumose 



I 



utero-albumoses 



W 



I 



Peptone-B 



Hetero-albumose 



I 



Deutero-albumoses 



I I I 



A B' C 



I I I 



Peptone-B 



Deutero-alburaose-B 



I 



Anti-albumid 



3utero-albumose-B' 



Peptone-B Peptone-A 



Whether or not the different albumoses which are thus formed 

 during the process of peptic digestion are qualitatively the same, 

 irrespective of their origin, we do not know, but it is likely that 

 certain differences exist. Quantitative variations also occur without 

 doubt, as is a priori suggested by the varying amounts of the amido- 

 acids of the fatty series and of the aromatic group which are con- 

 tained in the original albuminous molecule, as also by the absence 

 of a carbohydrate group in some of the albumins, the digestion of 

 which is quite analogous to that of the native albumins. The 

 principal points of difference between proto-albumose and hetero- 

 albumose are here given. 



HETERO-ALBUMOSE. 

 Contains 39 percent, of the total nitrogen 



in basic form. 

 The aromatic group is present only to a 



slight extent in a form which can give 



rise to tyrosin or indol. 

 Yields much leucin and glycocoll. 



PROTO-ALBUMOSE. 

 Contains 25 per cent, of total nitrogen in 



basic form. 

 Yields much tyrosin, viz., indol and 



skatol. 



Yields but little leucin and glycocoll. 



It is thus manifest that those albumins which are especially rich in 

 aromatic groups will furnish a correspondingly larger amount of 

 proto-albumose than those in which the fatty acid radicles are prin- 

 cipally found, and which accordingly yield a large amount of hetero- 

 albumose. That these differences will further become manifest in 

 the secondary products of decomposition is, of course, apparent. 



Of the character of the final products of peptic digestion, in the 

 sense of Kiihne, viz., the peptones, our knowledge is very imperfect. 



While according to older views amphopeptone was thought to 

 represent a chemical unity, Pick and others have shown that two 

 peptones at least result from the action of pepsin on albumin, one 

 of which is soluble in alcohol, while the other is insoluble. These 

 bodies, however, are most likely not units in themselves, but prob- 

 ably represent mixtures of other substances, which for the most part 

 are as yet unknown. 



