72 ACTIVITIES OF BACTERIA. 



1. Amins. Methylamin, di- and trimethylamin : 



/CH3 /CH3 /CH3 



\h ^H ^CH3 



similarly, ethylamin, di- and triethylamin. 



Ethylendiamin II /^ and its homologues dimethylethylendi- 



amin-putrescin, isomer of sepsin ; pentamethylendiamin, called 

 cadaverin, etc. Of these the most poisonous is ethylendiamin. 

 2. Ammonium bases. The best known is 



CH3 



Cholin = Bilineurin 



Nearly related are muscarin (C5H15NO3), vinylcholin (C5H13NO), 

 neuridin (CsHnNa), etc. . . 



3 Pyridin derivatives. Derived from pyndin (CsHsN), the 

 following are especially found : Collidin (CgHuN), parvolin 

 (C.HiaN). 



4. Indol (CjHjN) and skatol (C9H9N). Compare page 79. 



In addition the following are known : Amido=acids (leu- 

 cin, tyrosin, etc.) related to guanidin, C(NH)(NH2)2, 

 and also numerous, insufficiently or feebly characteristic 

 bodies, whose enumeration here would be useless, since the 

 poisons among them are not now recognized as the essen= 

 tial disease poisons, as was the case in former years. 



The isolation of these bodies can here be only hinted at. The method 

 of Brieger, which is most employed, is as follows : Brief boiling of the 

 culture or ' ' decomposed material ' ' rendered weakly acid with hydro- 

 chloric acid ; reduction of the filtrate to a syrup ; dissolve in 96 % alco- 

 hol and free from impurities (especially traces of albumin) with lead 

 acetate ; removal of the lead ; concentration of the filtrate and precipi- 

 tation from this of the double salt of mercury of the ptomain by means 

 of an alcoholic sublimate solution. After removal of the alcohol by 

 heat and the mercury by hydrogen sulphid, there is produced the 

 characteristic double gold and platinum compound, whose crystalline 

 quality is an index of its purity. One may try to obtain directly the 

 crystalline hydrochlorate, and by the aid of caustic soda the free bases, 

 which are often fluid. 



Some ptomains, like very many plant alkaloids, as 

 soon as set free by caustic soda, are easily obtained in 

 aqueous solution with ether. Still, Brieger' s procedure is 

 widely useful, as it takes into consideration many bodies 



