198 BACILLUS TUBERCULOSIS. 



Milk is centrifuged and the sediment examined for the 

 bacilli. The film is placed first in chloroform for from four 

 to six minutes in order to extract the fat. The chloroform 

 is then evaporated over the flame, and the preparation is 

 stained and mounted in the usual way. 



Animal inoculation may often have to be resorted to in the 

 examination of tubercular material before a positive diagnosis 

 can be made. Confirmatory evidence is also obtained by in- 

 oculation of animals. 



