ANTHRAX 59 



possessed of tough capsules, which resist the action of the ordinary 

 stains much in the same way as the tubercle bacillus. Thus 

 it happens that in films of a cultivation of the anthrax bacillus 

 which have been stained with such a dye as weak methylene blue 

 the spores are readily seen as colourless and refractile oval areas 

 in the centre of the bacilli, the latter being stained blue. The 

 spores themselves may be stained by a modification of the 

 process used for the tubercle bacillus. The films are first stained 

 by heated carbol fuchsin, which penetrates slowly through the 

 capsule ; they are then decolorized by a very rapid immersion 

 in very dilute sulphuric acid (i per cent.) or in methylated spirit, 

 and examined microscopically. If the red colour has been entirely 

 removed from the bacilli, but is still present in the spores, the films 

 are ready to be counterstained by methylene blue ; if not, they 

 must be dipped in the acid or spirit once more and re-examined. 

 When this process is successful, the spores are stained red, and 

 the bacilli blue (Plate I., Fig. 4). 



The presence of spores enables us to isolate the bacilli from most 

 of the organisms with which they are likely to be contaminated, 

 by a very simple process. The spores resist the action of heat 

 just as they resist stains, and for the same reason, and a suitable 

 temperature will kill off all the non-sporing organisms and spare 

 the spores. The latter may then be inoculated at a suitable 

 temperature, and will develop into bacilli. This process, however, 

 is not applicable to the examination of the blood or morbid 

 effusions, as the bacillus of anthrax does not form spores in the 

 living body. In this it differs from the tetanus bacillus, in which 

 the process may be applied direct to the material from the body. 



Investigation of a Supposed Case of Malignant Pustule. 



Requisites, — i. Several glass pipettes ; if cultures are not 

 required, one will be enough. 



2. Clean slides and cover-glasses. 



3. Bunsen burner or spirit-lamp. 



4. Loffler's methylene blue ; also the materials for Gram's 

 staining. 



5. Balsam. 



6. Tubes of gelatin if cultivations have to be taken. 

 Method.— Break off the extreme tip of one of the glass pipettes 



and insert into one of the vesicles around the dark papule in the 



