276 MANUAL OF BACTERIOLOGY. 



especially those whose occupations bring them in contact 

 with cattle or with the hides and wool of animals that die 

 of the disease. The infection may enter through wounds 

 of the skin, where it usually produces a localized inflam- 

 mation known as malignant pustule. Anthrax of the lungs 

 may be acquired by inhalation of material containing the 

 spores of the bacilli (" Wool-sorter's disease "). Infection 

 FlG by way of the intestine oc- 



curs occasionally but is less 

 common. Laboratory 

 workers engaged in study- 

 ing the anthrax bacillus 

 have been accidentally in- 

 fected in a number of in- 

 stances. 



The anthrax bacillus, 

 owing to its large size, 

 was the first of the patho- 

 genic bacteria to be recog- 

 nized, and its study has 



Anthrax bacilli with square or f urn i s h e d the basis for 

 slightly concave ends sometimes seen ; , r 



much of our knowledge 



fuchsin stain. (X 1000.) . & 



concerning the infectious 



diseases. It was for anthrax that Pasteur developed the 

 idea of making a protective vaccine, shortly after he had 

 invented a similar vaccine for chicken-cholera. There is 

 some danger attending its use. 



In order to obtain material free from spores the blood of 

 an animal which has recently died of anthrax is taken, 

 because anthrax spores do not form in the living body. 

 Cultures made in bouillon are kept at a temperature of 

 from 42 to 43 C. At this temperature spores do not 

 form, while the virulence of the anthrax bacillus becomes 

 gradually diminished. In time the virulence is so far 

 diminished that rabbits will survive inoculation, and even- 



