38 CHEMISTRY OF THE PROTEIDS CHAP. 



most widely -distributed disintegration -products of albumin. It is 

 only absent in a few vegetable albumins, 1 and in some protamins. 2 

 (Compare tables on pp. 70-75.) 



Lysin is, according to Ellinger 3 and E. Fischer, 4 a-e-diamino- 

 caproic acid. It is dextro-rotatory, and is converted, as are all other 

 amino- acids, into an inactive form on being heated under pressure 

 with barium hydrate. 5 It is, according to Ellinger, the mother- 

 substance of pentamethylene-diamin or cadaverin : NH 2 (CH 2 ) 5 NH 2 . 

 A fuller description of its properties is given by Kossel, 6 Willdenow, 7 

 and Schulze and Winterstein. 8 For its isolation Kossel 9 makes use 

 of the insolubility of the picrate, and for its identification Herzog 10 

 prepares the phenylhydantoin having a melting-point of 183-184, as 

 this compound results from the union of lysin with phenyl-isocyanate. 



Amongst readily accessible albumins, lysin is found in greatest 

 quantities in casein and in gelatine. According to Henderson, 11 

 Kutscher, and Steudel, 12 the nitrogen-determination by KjeldahFs 

 method does not always give correct values, probably because a part 

 of the nitrogen is converted into hydrocyanic acid, as has been 

 observed by Zickgraf 13 on oxidising lysin with barium permanganate. 



Diamino-valerianic Acid, or Ornithin, is discussed under 

 Arginin on p. 40. 



13. Arginin, C 6 H 14 N 4 2 



NH 2 NH 2 



I H H H | ,0 



NH = c N c c c c c<; 



H H H H H X OH, 



is guanidin-d-amino-normal-valerianic acid. 

 Guanidin has the formula NH : C (NH 2 ) 2 . 

 Besides lysin Drechsel u prepared from casein a second base, the 



1 A. Kossel and F. Kutscher, ibid. 31. 165 (1900). 



2 A. Kossel and F. Kutscher, ibid. 31. 165 (1900) ; A. Kossel, ibid. 26. 588 (1899). 



3 A. Ellinger, Ber. d. deutsch. chem. Ges. 32. III. 3544 (1899) ; Zeitschr. f. 

 physiol. Chem. 29. 334 (1900). 



E. Fischer and F. Weigert, Ber. d. deutsch. chem. Ges. 35. III. 3772 (1902). 



M. Siegfried, Ber. d. deutsch. chem. Ges. 24. I. 418 (1891). See also Zeitschr.,/. 

 physiol. Chem. 43. 363 (1905). 



A. Kossel, ibid. 26. 586 (1899). 7 01. Willdenow, ibid. 25. 523 (1898). 



E. Schulze andjE. Winterstein, 'Ergebnisse der Physiologic,' I. ibid. p. 57 (1902). 



A. Kossel, Zeitschr. f. physiol. Chem. 26. 586 (1899) ; A. Kossel and F. Kutscher, 

 ibid. 31. 165 (1900). 



10 E. 0. Herzog, ibid. 34. 525 (1902). " Y. Henderson, ibid. 29. 320 (1900). 



12 F. Kutscher and H. Steudel, ibid. 39. 12 (1903). . 



13 Zickgraf, Ber. d. deutsch. chem. Ges. 35. III. 3401 (1902). ' 



14 E. Drechsel Sitzungsber. d. Sachs. Ges. d. Wissensch., math.-nat. Kl. 1889, 1890 ; 

 Arch. /. (Anat. u.) Physiol. 1891, p. 248. 



