68 



SCIENCE PROGRESS. 



Many pathogenic germs grow well on a fluid devised by 

 Gamaleia, which is wholly free from proteids, but contains 

 glycerine, common salt, and Liebig's extract of meat. 



The investigations of Ouchinsky l have been carried out 

 on media which contain neither proteid nor peptone, but 

 only well-known chemical substances. In his first commu- 

 nication the medium has the following composition :- 



For some pathogenic organisms, such as Loffler's diphthe- 

 ria bacillus, "5 per cent, of urea, or "02 per cent, of uric acid 

 is added, and in some cases a variable amount of sugar. 



On this fluid neither the bacillus tuberculosis nor 

 Eberth's typhoid bacillus will grow, but the Spirillum of 

 cholera and the Vibrio avicide {Metcknikovi) develop 

 luxuriantly. Loffler's bacillus grown on the fluid without 

 the addition of urea or uric acid yields a filtrate the toxic 

 property of which is not very marked, 15-13 cc. being 

 required for a lethal dose, while with the addition of urea 

 or uric acid a filtrate is obtained 1*5 cc. of which is fatal. 

 The cultures obviously vary in virulence, and the attenua- 

 tion of this in the first case is permanent. The suc- 

 cessive generations of a culture primarily weakened on 

 Ouchinsky's fluid are found when grown upon ordinary 

 glycerine bouillon to remain in this condition. The virus 

 is absolutely attenuated and capable of remaining so in 

 successive generations. The toxines of cholera and diph- 

 theria examined chemically give Millon's reaction for 

 proteid, and respond to the biuret and xanthoproteic 

 tests. Corrosive sublimate, alcohol, lead acetate, acetic 



1 Ouchinsky, Archives de med. exp., No. 3, 1893. 



