120 BACTERIAL ANALYSIS. 
and study the colonies that resemble those of 
Bacillus coli. 
6. Milk Analysis.—The analysis of milk is 
conducted in the same manner as is that of water, 
but on account of the great number of bacteria in 
Fic. 53.—Hesse’s apparatus for collecting bacteria from the 
air. 
milk the samples must be diluted with sterile 
water. 
Bacillus typhosus and Bacillus coli are detected 
in milk by the same methods as in water analysis. 
Tuberculosis bacilli may be detected in milk by the 
method described in the next chapter.' 
1 See page 157. 
