STAINING TUBERCLE BACILLI IN TISSUES. 197 



In case it is desired to stain sections cut by the freez- 

 ing method, they are placed upon a slide on which a 

 few drops of the gelatin fixative have been placed, and 

 after about five minutes, during which the fixative will 

 have penetrated the section, the surplus is poured from 

 beneath the section. The slides are then set aside for 

 the gelatin to harden by drying, and after drying they 

 are placed in bichromate fluid to render the gelatin 

 insoluble. They are then manipulated in exactly the 

 same manner as the sections cut by the paraffin method. 



This method gives equally as good results with tissues 

 containing the lepra bacillus as with those containing 

 tubercle bacilli. 



