122 BACTERIOLOGY. 



spermin, which, according to Kobert, is iden- 

 tical with piperazin or diethylene diimin ( (NH) 2 

 (CH 2 ) 4 ). Poehl, however, disputes this identity 

 and ascribes to the substance the formula (C 5 H 14 

 N 2 ) x . The substance tyrotoxicon, discovered 

 by Vaughan in cheese, seems to be derived from 

 butyric acid or butyl-aldehyde. 



It is a curious fact that a colored alkaloid base 

 or ptoma'inic pigment has been discovered, the 

 so-called pyocyanin (Ci 4 H 14 N 2 O), which pro- 

 duces the color of blue or blue-green pus and has 

 been regarded by Ledderhose as related to the 

 coal-tar products. Similar bodies of a basic 

 nature may be found in the intestinal contents 

 as the products of bacterial decomposition. 

 Some of these are poisons, and can be absorbed 

 into the body, where they play the role of 

 self-poisons or leucomains. Perhaps the 

 symptoms designated as coma and tetany may 

 be ascribed to something of this nature. 

 Katabolic products also sometimes originate 

 in the body which may accumulate in great 

 quantities, and produce auto-intoxication and 

 fatigue. Some of these substances are related 

 chemically to the ptomai'ns. 



In some cases of poisoning due to decompos- 

 ing meat or sausage, or to cheese or milk, 

 ptomai'ns, according to researches made in my 

 laboratory, may not be concerned at all, or if 



