33 



Malignant Edema 



conditions. The best preparation, therefore, is made by heating 

 the gelatin to expel any air it may contain, inoculating it while still 

 liquid, and solidifying it in cold (iced) water. In such a tube the 

 bacilli develop in globular circumscribed areas of cloudy liquefaction 

 which contain a small amount of gas. In gelatin to which a little 

 grape-sugar has been added the gas production is marked. 



Agar-agar. The growth takes place in the form of a cloudy 

 stream, in the lower part of deep punctures in recently heated 

 agar-agar, from which the air has been expelled. If the agar-agar 

 contains i per cent, of glucose, it is soon split up by the gas for- 

 mation. Such cultures give off a very disagreeable cdor. 



Fig. 117. Bacillus of malignant edema, from the body-juice of a guinea-pig 

 inoculated with garden earth. X 1000 (Frankel and Pfeiffer). 



Bouillon. In deep tubes of recently heated bouillon a diffuse 

 turbidity occurs in about twenty-four hours. After the third day 

 the upper half clears, the bacilli and spores sedimenting or moving 

 away from the oxygen. The culture gives off a very disagreeable 

 odor. 



In glucose or other sugar bouillon in the fermentation tube, 

 considerable gas is formed. 



The gas is partly inflammable, partly not. 



Milk. Milk is slowly coagulated. 



Potato. The bacillus grows upon the surface of potato if kept 

 under anaerobic conditions. 



Blood-serum. Upon coagulated blood-serum, and upon coagu- 

 lated egg-white, growth occurs under anaerobic conditions, both 

 media being slowly digested and softened. 



Vital .Resistance. The bacilli themselves soon succumb when ex- 

 posed to the air. They are destroyed in a few moments by heating 



