THE PROTEIN SUBSTANCES. 97 



first of these is known as heteroalbumose and is insoluble in 

 weak alcohol, while the second, or alcohol-soluble portion, is 

 called protalbumose. The heteroalbumose belongs to the 

 above-mentioned anti group and is further changed only with 

 difficulty. The protalbumose belongs to the hemi group. It 

 is quite soluble in water, and in dilute alcohol even more sol- 

 uble. By prolonged peptic digestion the protalbumose passes 

 into the secondary albumose known as deuteralbumose A, and 

 then into peptone B. 



These two primary albumoses contain no carbohydrate 

 group, since they give no reaction with the Molisch or Adam- 

 kiewicz test. The heteroalbumose, on complete splitting, fur- 

 nishes much leucine and glycocoll, but little or no tyrosine ; the 

 protalbumose, on the contrary, yields a large amount of tyro- 

 sine, but little leucine and no glycocoll. These reactions point 

 to essential differences in structure. 



Like the primary albumose fraction, the secondary fraction 

 may also be further subdivided and chemists have recognized 

 two or three products here which have been called deuteral- 

 bumose A, deuteralbumose B and deuteralbumose C. But the 

 exact relations of each one of these to the primary products 

 are not yet clearly established. A fourth body called deuteral- 

 bumose Ba has also been described, but it is now generally 

 recognized as a primary product. In addition to these four 

 substances, which may be fairly definite chemical individuals, 

 authors have described a number of other precipitation frac- 

 tions which are probably mixtures. Of all these bodies the 

 deuteralbumose A and the deuteralbumose B are the only ones 

 for which the conditions of precipitation have been carefully 

 worked out. 



Peptones. The amount of real peptone formed by the 

 pepsin digestion is always small ; the large amount of peptone 

 produced in the body is a consequence of the action of the pan- 

 creas enzyme known as trypsin. The peptone of gastric 

 digestion is a mixture of products from the hemi and anti 

 groups and has been called amphopeptone. The term anti- 



