IMPORTANT PATHOGENIC BACTERIA 



137 



tight-fitting cover. Vaselin is smeared on the top of 

 the jar to insure a tight fit of the cover. A small piece 

 of absorbent paper wetted with a few drops of alcohol 

 is placed inside of the jar, the paper is lighted, and the 

 cover replaced. The burning paper absorbs the oxygen, 

 leaving the cultures in an atmosphere of nitrogen. 



When growth has been obtained by any of the above 

 methods, transfers should be made to milk, and gentian 



— a 



Fig. 33 

 Anaerobic Cultivation in Hydrogen Gas 



a. Novy jar e. Sodium hydrate solution 



b. Glass cock /. Opening of Novy jar 



c. Gas generator g. Stopper 



d. Sulphuric acid 



violet and Gram stains prepared. Motility should be 

 determined by preparing a hanging drop. Anaerobic 

 bacteria in a hanging drop will concentrate toward 

 the center of the drop away from the oxygen of the air. 

 6. Special study. — Inoculation of a rabbit with B. 

 welchii. 



a) Shave the ear of the rabbit. 



b) Wash with mercuric chlorid solution and alcohol. 



