1286 THE BILE-ACIDS. 



Two of the most clearly defined ptomaines are cadaverine 

 and putrescine. These are found in corpses which have under- 

 gone putrefactive decomposition, cadaverine appearing in the 

 earlier stages of putrefaction and putrescine preponderating 

 in the later. The latter is largely present in putrid her- 

 rings. The former is identical with pentamethylene-diamine 

 NH 9 (CH 2 ) 5 NH 2 . The latter has been shewn to have the con- 

 stitution of tetramethylene-diamine, NH 2 (CH 2 ) 4 NH 2 . They 

 have both recently been obtained as conspicuous constituents 

 of urine from a case of cystinuria and appear to owe their origin 

 to putrefactive processes occurring in the intestine. They are 

 both somewhat viscid fluids which crystallize at low tempera- 

 tures, and yield readily crystallizable compounds with acids 

 and salts of gold, platinum and mercury. Their benzoyl com- 

 pounds are insoluble in water and hence afford a convenient 

 means for their separation. Choline and the highly toxic neu- 

 rine, which really belong to this class, have already been 

 described. (See above, pp. 1239, 1240.) 



Leukomaines. 1 This name has been applied to those basic 

 (alkaloidal) substances which occur in living tissues and are to 

 be regarded as products of their normal metabolism and thus 

 distinct from ptomaines. They are obtained by extracting 

 finely minced ox-flesh with an extremely dilute aqueous solu- 

 tion of oxalic acid. This extract may contain the following 

 six bases: Xanthocreatinine, C 5 H 10 N 4 O; Chrysocreatinine, 

 C 5 H 8 N 4 O; Amphicreatinine, C 8 H 19 N 7 O 4 ; Pseudoxanthine, 

 C 4 H 5 N" 5 O, and two, as yet unnamed, with the composition 

 C n H 24 N 10 O 5 and C 12 H 2 .N n O 5 respectively. They probably 

 stand in close relationship to paraxanthine, C 7 H 8 N 4 O 2 , hetero- 

 xanthine, C 6 H 6 N 4 O 2 , and adenine, C 5 H 5 N 5 (see above, p. 1264), 

 and it is interesting to note that comparing the formulae of 

 the leukomaines with each other and with those of creatinine, 

 C 4 H 7 N 2 O, and creatine, C 4 H 9 N 3 O 2 , they are found to differ in 

 several cases by the group CNH. 



The leukomaines are regarded by some authors as feebly 

 toxic alkaloidal products of metabolism from which the organism 

 is normally freed either by their excretion, since they are found 

 in urine, or by destructive oxidation, and it has further been 

 suggested that their abnormal retention in the economy may 

 be the cause of certain obscure pathological conditions. 



THE BILE-ACIDS. 

 1. Cholalic (or cholic) acid. C 24 H 40 O 5 . 

 This acid occurs in traces as a product of the decomposition 



1 The name is derived from \evKuna, occasionally used to denote white of 

 egg and hence to indicate their origin from proteids. 



