132 ; PATHOGENIC BACTERIA. 
or in vapor of formaldehyd two and a half minutes; 
or heat in the thermostat at 110°-120° C. for twelve 
hours ; or heat on a brass plate for one hour at the 
point where water boils. 
Fic. 67.—Bacterium anthracis; cover-glass preparation 
from the spleen of a mouse (Mallory and Wright). | 
3. Stain in eosin (4 per cent. in 60 per cent. 
alcohol) from one to five minutes. 
4. Wash in water and dry. 
5. Contrast-stain in aqueous methylene-blue from 
one-half to one minute. 
6. Wash, dry, and mount, 
