206 PTOMAINES. 



admit of no suitably brief description. The principle involved in 

 each consists in preparing a concentrated alcoholic, ethereal, or 

 chloroformic extract of the mother-substance, and from this 

 crystalline compounds of the alkaloids are prepared by the addi- 

 tion of suitable reagents. 1 A further means for their final separa- 

 tion consists in the formation of benzoylated compounds which are 

 insoluble in water. 2 



Alkaloidal substances, some poisonous, others inert, may also be 

 obtained both from normal but more particularly from pathological 

 urines. 3 



The first distinct evidence that the poisonous properties of cer- 

 tain (septic) fluids might be due to a specific chemical substance 

 rather than necessarily to the action of organisms in those fluids 

 is apparently due to Panum, who seems to have dealt with a 

 septic alkaloid in a very pure form, although he did not definitely 

 characterise it as a chemical substance. 4 This was followed by a 

 series of observations all tending in the same direction, but none 

 of the observers obtained the supposed specifically toxic substances 

 in forms which enabled them to be spoken of as chemical in- 

 dividuals until Nencki in 1876 5 isolated from the products of 

 the pancreatic putrefaction of gelatin a well-crystallised base 

 C 8 H U N, to which he assigned the constitutional formula 



/CH 3 

 C 6 H 5 CH and hence the name isophenyl-ethylainm. 



X NH 



Since then the ptomaines have been in most cases fairly definitely 

 and in some cases absolutely characterised as regards their chemi- 

 cal composition and constitution. They belong typically to the 

 class of substances known as amines and are in many cases dia- 

 mines. Two of the most clearly defined ptomaines are cadaverin 

 and putrescin. These are found in corpses which have undergone 

 putrefactive decomposition, cadaverin appearing in the earlier 

 stages of putrefaction, and putrescin preponderating in the later. 

 The latter is largely present in putrid herrings. 6 The former is 

 identical with pentamethylen-diamine NH 2 (CH 2 ) 5 NH 2 . 7 The 

 latter has been shown to have the constitution of tetramethylen- 

 diamine NH 2 (CH 2 )4NH 2 . They have both recently been obtained 

 as conspicuous constituents of urine from a case of cystinuria, and 



1 For description of these methods see Halliburton, Chem. Physio', and Pathol. 

 1891, p. 175. Otto, toe. at. S. 103. 



- Udranszky u. Baumann, Zt. f. phi/siol. Chem. Bd. xm. (1889), S. 562. 



3 For details and literature see Neubauer u. Vogel, Anal. d. Hams. 1890, S 241 

 et seq. 



* Published originally in Danish in Bibliothek. f. Ldqer, April, 1856, S. 253 

 Fully abstracted in Schmidt's Jahrbiicher d. yes. Med. Bd. ci. (1859), S. 213, and 

 republished in Virchow's Arch. Bd. LX. (1874), S. 301, with literature up to date. 



6 Ueb. d. Zersetz. d. Gelatine u. s. w. Bern, 1876. See later Jn. f. prakt. Chem. 

 Bd. xxvi. (1882), S. 47. 



6 Bocklisch, Ber. d. d. chem. Gesell. Bd. xvm. (1885), Sn. 86, 1922; xx. (1887), 

 S. 1441. 



7 Ladenburg, Ibid. Bd. xix. (1886), S. 2585. 



