74 THE NITROGENOUS DERIVATIVES OF THE ALBUMINS. 



decomposition it yields ammonia, oxalic acid, propionic acid, and 

 notably acetic acid. When exposed to the influence of putrefac- 

 tive organisms it gives rise to the formation of cadaverin penta- 

 methylene-diamin a ptomain which is frequently found together 

 with pntrescin in putrefying albuminous material, and, like this, may 

 also appear in the urine in association with cystin. Its formation is 

 quite analogous to that of putrescin from ornithin, and may be 

 represented by the equation : 



CH 2 (NH 2 ).CH 2 .CH 2 .CH 2 .CH(NH 2 ).COOH = 



Lysm. CO 2 + CH 2 (NH 2 ).CH 2 .CH 2 .CH 2 .CH,(NH 2 ) 



Cadaverin. 



In this manner, also, albumins can give rise to the formation of 

 pyridins, and, as a matter of fact, piperidin results during the dry 

 distillation of cadaverin, as represented by the equation : 



CH 2 -CH 2 



CH 2 (NH 2 ).CH 2 .CH 2 .CH 2 .CH 2 (NH 2 ) = CEL NH + NH 3 . 



CH 2 CH 2 



On treating lysin with benzoyl chloride Drechsel obtained a 

 body, of the formula C 6 H 12 (COC 6 H 5 ) 2 N 2 O 2 , which he termed lysuric 

 acid, and which is thus homologous with the dibenzoyl derivative 

 of ornithin, C 5 H 10 (COC 6 H 5 ) 2 N 2 O 2 , orniihuric acid. 



Histidin. Of the nature of histidin comparatively little is 

 known. This is largely owing to the fact that the substance is 

 formed only in very small amounts during the decomposition of 

 albumins. From 200 grammes of antipeptone Kutscher thus ob- 

 tained only 1.4 grammes of histidin, as compared with 10.4 grammes 

 of arginin. Its formula, according to Kossel, is C 6 H 9 N 3 O 2 . 



THE NUCLEINIC ACIDS. 



In a preceding chapter it w^as pointed out that the so-called 

 nucleins can be divided into two classes, viz., into the paranu- 

 cleins, or pseudonucleins, and into the true nuclear nucleins. It- 

 was shown, moreover, that in the nuclear nucleins an albuminous 

 radicle is combined with organic phosphorus-containing acids, the 

 so-called nucleinic acids. Our knowledge of these bodies is very 

 limited, and a satisfactory classification impossible. For con- 

 venience' sake I divide the nucleinic acids into two groups, viz., 

 the primary acids, which occur in nature either free or in com- 

 bination with albumins (including the protamins), and the sec- 

 ondary acids, which result from decomposition of the primary acids. 

 These latter are characterized by the fact that on decomposition 

 they all yield nucleinic bases, while this is not necessarily the case 

 as regards the secondary acids. According to their origin, these 

 primary acids have been termed spermanucleinic acid, thymo- 

 nucleinic acid, yeast-nucleinic acid, etc. There is reason to assume, 



