GENUS BACTERIUM 229 



been drawn post mortem from three cows that had died from 

 anthrax. Moore ll found the anthrax organism in the milk of 

 a cow at the time of her death but failed to find it in the milk 

 of cows in advanced stages of the disease. 



Bacteria resembling Bacterium anthracis. Several spe- . 

 cies of bacteria resembling more or less closely Bacterium 

 anthracis have been described. The accompanying table by 

 Fitch 12 summarizes the anthrax-like bacteria that may be 

 mistaken for Bacterium anthracis in making a diagnosis. 



Vaccine. Pasteur found that when susceptible animals 

 were inoculated with an attenuated culture of Bact. anthracis 

 immunity was established. He attenuated the organism by 

 cultivating it at a temperature of from 42 to 43 C. The 

 method of vaccinating, or of securing active immunity against 

 anthrax, in animals is as follows: Two anthrax cultures of 

 varying degrees of attenuation are used as vaccines. The 

 first vaccine is a culture which has lost its virulence for guinea- 

 pigs and rabbits and is potent only for mice. The second vac- 

 cine is a culture which is still definitely virulent for mice and 

 guinea-pigs, but not potent for rabbits. Forty-eight-hour 

 bouillon cultures of these attenuated organisms grown at 

 37.5 C. constitute the vaccine actually employed. Vaccine is 

 subcutaneously injected into cattle in doses of 0.25 cc. ; sheep 

 are given about half the quantity. After twelve days have 

 elapsed similar quantities of Vaccine II are injected. 



Active immunization of small laboratory animals is very 

 difficult, but can be accomplished by careful treatment with 

 extremely attenuated cultures. 



11 Moore. Kept, of the N. Y. State Dept. of Agric., 1897. 



12 Fitch. Report N. Y. State Vet. College, 1910, p. 200. 



