Vn. KOCH-BHRLICH METHOD OF STAINING TU- 

 BERCLE BACILLI IN SECTIONS. 



1. Section from alcohol to freshly prepared aniline- 

 water-fuchsin solution/ for at least twelve hours at room 

 or incubator temperature. 



2. Decolorize in 25 per cent, nitric acid from ten to 

 thirty seconds. 



3. Continue decolorization in alcohol until section is 

 pinkish-white. 



4. Contrast stain in watery methylene-blue solution 

 one or two minutes. 



5. Dehydrate in alcohol. 



6. Oil, balsam. 



iSee m, foot-note 2, a and b. Instead of aniline-water-fuehsin so- 

 lution, aniline-water-gentian-violet, or methylene-blue, may be used, 

 but the latter stains do not seem to be retained so permanently. 



27 



