478 



Anthrax 



Milk. The anthrax bacillus grows well in milk, which 

 it coagulates. Later the coagulum is peptonized and dis- 

 solved, leaving a clear whey. The reaction is not altered. 



Thermic Sensitivity. The bacillus grows between the 

 extremes of 20 and 45 C., best at 37 C. The exposure of 

 the organism to the temperature of 42-43 C. slowly di- 

 minishes its virulence. 



When dried upon threads, the spores retain their vital- 

 ity for years, and are highly resistant to heat and disinfec- 

 tants. The spores of anthrax are killed by five minutes' 

 exposure to 100 C. It is said by some that spores sub- 



Fig. 145. Bacillus anthracis; gelatin puncture culture seven days old 



(Gunther). 



jected to 5 per cent, carbolic acid can subsequently ger- 

 minate when introduced into susceptible animals, their 

 resistance to this strength carbolic solution being so great 

 that they are not destroyed by it under twenty-four hours. 

 They are killed in a short time by exposure to i : 1000 

 bichlorid of mercury solution. 



Metabolic Products. The anthrax bacillus produces a 

 curdling ferment. It produces no important change of 

 reaction in the medium in which it grows, and generates no 

 indol. Its proteolytic enzyme is active, digesting both 

 casein and fibrin. 



It is doubtful whether the anthrax bacillus produces any 

 important toxic substance. Hoffa * isolated a basic sub- 

 * "Ueber die Natur. des Milzbrandgifts," Wiesbaden, 1886. 



