BACILLI OF CHAUBERTS DISEASE. I99 



necessary to employ the method described in Chapter 

 v., and in order to obtain a pure culture to prepare 

 with a small trace of the exudatioa an Bsmarch's tube 

 in an atmosphere of hydrogen, and to keep it in an 

 incubator at a temperature of from 20° to 22° C. 

 After two or three days white colonies, which liquefy 

 the gelatine rapidly, make their appearance. If some 

 strong grape-sugar gelatine be placed in a test-tube 

 and be inoculated with a portion of one of these 

 colonies, the anaerobic nature of these bacilli very 

 soon becomes apparent. They flourish even at ordi- 

 nary temperatures, and liquefy the gelatine very 

 energetically. This liquefaction, if too many spores 

 have not been transferred, commences about a thumb's 

 thickness below the surface, being caused by small 

 isolated colonies, which are formed along the track 

 of the needles and which soon coalesce ; it progresses 

 however very rapidly, so that very soon a thick 

 whitish column of liquid indicates the path of the 

 needle. Bubbles of gas, which at first are kept under 

 the solid surface of the gelatine, are formed, whilst 

 the liquefaction continues to spread rapidly until the 

 sides of the test-tube are reached. Finally even the 

 solid upper portion of the gelatine is liquefied by the 

 action of ferments produced by the bacteria, and then 

 the bubbles of gas rise to the surface of the medium, 

 which is now entirely fluid. Very peculiar-looking 

 cultures are obtained by thoroughly mixing a small 



