CHEMISTRY OF TlfK PTOMAIN'ES. 213 



I 111). Cadaverine si-cms to be a constant product of the 

 activity of the genus vibrio, inasmuch as it does not occur 

 in cultures in which this genus is absent. Thus, it is not 

 present in the excrements of healthy or typhoid patients ; in 

 cultures <>!' KMMKIMCH'S bacillus, of EBERTH'S bacillus, and 

 of the mrogenk bacteria. It is said to occur in cultures of 

 the Icieillus of hoy;- cholera (v. ScHWEiNiT/). OECHSNER 

 DE CONINCK has found it in putrid jelly-fish (HuGOUNENQ, 

 page 23). It is present with putrescine in the urine and 

 feres of cystinuria (UDRANSZKY and BAUMANN, 1888). 

 The odor of cholera stools and the breath of cholera patients 

 may be possibly due to cadaverine, although the base has 

 not been demonstrated in such cases. It has also been ob- 

 tained from caviar. 



Cadaverine occurs in the mercuric chloride precipitate, 

 from which it is isolate/! according to the methods given on 

 pages 206 and 221. For its isolation and separation from 

 putrescine by the use of benzoyl chloride, see page 208. 



This, base was at first ascribed the formula C 5 H 16 N 2 , but 

 subsequent researches led BRIEGER and BOCKL.ISCH to the 

 adoption of the formula C 5 H U N 2 . In 1883, LADENBURG 

 prepared, as the first step in the synthesis of piperidine, a 

 base, pentamethylenediamine, possessing the same empirical 

 formula as cadaverine, and later (Ber. 18, 2956) he showed 

 the possibility of the identity of these two bases. This led 

 to their direct comparison ami the successful establishment 

 of their identity. In fact, LADENBURG, as a crucial test of 

 the identity, converted cadaverine into piperidine, and found 

 the latter base to agree entirely in its chemical and physical 

 properties with those of the natural alkaloid (Ber. 19, 2586). 

 LADENBURG, however, observed one apparent difference 

 between cadaverine and pentamethylenediamine, and that 

 \vas in the composition of the mercury double salts. That 

 of the former base, whether obtained from alcoholic or 

 aeneous solution (Boc'KLiscii, Ber. 20, 1441), was found 

 to combine with four molecules of mercuric chloride; 

 whereas the double salt of pentamethylenediamine was 

 found by LADENBURG to contain only three molecules of 

 mercuric chloride. Subsequently he found that he had 



10* 



