Microbic Diseases Individually Considered. 197 



finally destroyed by the oxygen of the air. The same 

 thing occurs when they have penetrated to a slight 

 depth in permeable soil. But when they are buried 

 at a sufficient depth, especially in a compact clayey 

 soil, they are preserved for a considerable time on ac- 

 count of the absence of oxygen and light, and they 

 may even, by virtue of their anaerobic faculty, propa- 

 gate themselves there. 



Strong antiseptics are fatal to the bacillus Chauvcei ; 

 Arloing, Cornevin, and Thomas have observed this 

 toxic action after twenty-four hours' contact with sub- 

 limate, at 1 to 5,000, chlorine gas, and two per cent 

 solution of carbolic acid ; on the other hand, sulfurous 

 acid, quick lime, and 90 per cent alcohol do not de- 

 stroy its virulence. 



Cultures. — Cultures of this microbe are very difficult 

 to obtain ; they are only possible when excluded from 

 oxygen, in a vacuum, or in presence of an inert gas, 

 such as carbonic acid.* Bouillons to which have 

 been added glycerin and ferrous sulfiite, or gelatin 

 and sugar, are the media to be preferred. The fluid 

 rapidly becomes turbid and the seat of an intense dis- 

 engagement of gas ; it exhales a pronounced odor of 

 rancid butter. 



Attempts at cultivation on solid media have also 

 been successful. Upon gelatin there are produced 

 spherical verrucose colonies, which fluidify the me- 

 dium and give rise to a lively production of gas ; cult- 

 ures upon agar have a penetrating acid odor. Viru- 

 lence does not long persist in generations obtained by 



* [" Grows in an atmosphere of hydrogen but not in carbon di- 

 oxide." Sternberg: Manual of Bacteriology, p. i94. — D.] 



