468 PATHOGENIC MICROORGANISMS 



pepton solution obtained from the macerated tissues of the stomachs of 

 pigs. The toxin contained in filtrates of such cultures is quite resistant 

 to heat, but rapidly deteriorates if free access of air is allowed. 



Immunity. — Active immunization against the bacillus of symptom- 

 atic anthrax was first accomplished by Arloing ^ and his collaborators 

 by the subcutaneous inoculation of cattle with tissue-extracts of in- 

 fected animals. The work of these authors resulted in a- practical 

 method of immunization which is carried out as follows: 



Two vaccines are prepared. Vaccine I consists of the juice of in- 

 fected meat, dried and heated to 100° C. for six hours. Vaccine II is a 

 similar meat-juice heated to 90° C, for the same length of time. By 

 the heating, the spores contained in the vaccines are attenuated to 

 relatively different degrees. Vaccine I in quantities of 0.01 to 0.02 

 c.c. is emulsified in sterile salt solutions and injected near the end of 

 the tail of the animal to be protected. A similar quantity of Vaccine II 

 is injected in the same way fourteen days later. 



This method has been retained in principle, but largely modified in 

 detail by various workers. Kitt ^ introduced the use of the dried and 

 powdered whole meat instead of the meat juice, and made only one 

 vaccine, heated to 94° C, for six hours. This method has been largely 

 used in this country.^ Passive immunization with the serum * of 

 actively immunized sheep and goats has been used in combination with 

 the methods of active immunization. 



BACILLUS OF MALIGNANT EDEMA 



{Bacillus wdernatis maligni, Vibrion septique) 



In 1877, Pasteur ^ described a bacillus which he had found in guinea- 

 pigs and rabbits experimentally inoculated with putrefying animal 

 tissues. This bacillus, which he named "Vibrion septique," he suc- 

 ceeded in cultivating only under anaerobic conditions and in an impure 

 state, and described as its pathognomonic characteristics the formation 

 of an extensive edema in and about the point of inoculation. 



1 Arloing, Cornemn, et Thomas, " Le Charbon Sympt.," etc., Paris, 1887. Ref. 

 from Grassberger und Schattenfroh, Kraus und Levaditi, "Handbuch," etc., vol. 

 i, pt. 2. 



2 Kitt, Ref. from Grassberger und Schattenfroh, loo. cit. 



3 Report of Bureau of Animal Ind., Wash., 1902. 

 ' Arloing, Leclainche, et Vallie, loc. cit. 



5 Pasteur, Bull, de I'acad. de med., 1877, p. 793. 



