BACTERIUM COLI COMMUNIS 



175 



of the virus varying according to the severity of the processes from which 

 it was originally isolated. 



For the differentiation of the Bacillus coli communis and Bacillus 

 typhi abdominalis, Piorkowski institutes cultures in bouillon, gelatine, 

 and agar, prepared with urine, to which the desired quantity of peptone, 

 gelatine, and agar is added ; sterilization, etc., being accomplished in 

 the ordinary manner. 



Cesaris-Demel (Giornale delta R. Accad. di Medicina di Torino, 1898, 

 No. 3) describes a new method for the differential diagnosis of the 

 typhus bacillus and the B. coli communis as follows : 



Cultures of the organisms are instituted in bouillon prepared from a 

 calf s liver. The sugar present in the liver will be fermented by the 

 B. coli communis, and it will exhibit a quick luxurious growth, while on 

 this medium the growth of the typhus bacillus is confined to very narrow 

 limits. 



DIFFERENTIAL DIAGNOSIS TABLE. 



