xi THE ALBUMINOIDS: GELATINE 561 



crystalline dissociation-products, or only to traces. In their place are 

 found not only antipeptones, which Kriiger l has described and from 

 which Siegfried first isolated kyrin (p. 200), but according to Chittenden 

 and Solley 2 and Klug 3 also albumoses, which as a rule are very 

 quickly destroyed. 



On subjecting gelatine to tryptic digestion for ten months * 

 Levene 4 obtained in the main only albumoses and peptones, and \ 

 noticed the peculiar fact that the primary dissociation-compounds of i 

 gelatine, namely the gelatoses, contain more glycocoll than does the ' 

 original gelatine, but that the secondary products, namely the peptones, 

 contain again less glycocoll than the gelatoses. An explanation was 

 found, for the gelatoses in becoming peptones split off glycocoll, which, 

 along with traces of leucin, represents nearly the whole of the mono- 

 amino-acid-fraction liberated by digestive enzymes. FromT 1500 grams 

 of gelatine, alter ten'months' digestion, Levene obtained 40 grams of 

 glycocoll-ester, a small amount of leucin, traces of phenylalanin, 

 glutaminic and aspartic acids, but large amounts of ammonia. From 

 the phosphotungstic acid precipitate a copper salt of the racemic 

 pyrrolidin-carboxylic acid was obtained. 



Peptic digestion, according to Scheermesser, 5 proceeds likewise 

 slowly, and gives rise to peptones only at a late period ; ' anti-albumid ' 

 is, however, formed abundantly. 6 On combining tryptic digestion 

 with putrefaction Nencki 7 obtained similarly only small quantities of 

 leucin and glycocoll ; most of the products gave the biuret reaction. 



Scheermesser in his last paper describes a new pepsin-glutin 

 peptone in which arginin, lysin, glutaminic acid and glycocoll were 

 present while histidin was certainly absent. 



The percentage distribution of nitrogen in the pepsin-glutin-peptone 

 molecule, taking the mean of two experiments is as follows : 



1 T. R. Kriiger, Zeitschr. f. physioL Chem. 38. 320 (1903). 



2 R. H. Chittenden and F. P Solley, Journ. of Physiology, 12. 23 (1891). 



3 F. Klug, Pfluger's Arch. f. d. ges. PhysioL 48. 100 (1891). 



4 P. A. Levene, Zeitschr. f. physioL Chem. 41. 8 and 99 (1904). 



5 W. Scheermesser, ibid. 37. 363 (1903) ; Philosophical Dissertation, Leipzig, 1903 ; 

 Zeitschr. f. physioL Chem. 41. 68 (1904). 



6 R. H. Chittenden and F. P. Solley, Journ. of PhysioL 12. 23 (1891) ; F. Klug, 

 PJluger's Arch. f. d. ges. PhysioL 48. 100 (1891). 



7 M. Nencki, Ber. d. deutsch. chem. Ges. 7. II. 1593 (1874). 



[TABLE 



2 O 



