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BACTERIOLOGICAL ANALYSIS OF MILK. 



ing these tests day by day the dairyman can discover the 

 sources of excessive contamination and frequently can re- 

 move them. The dairyman can also in this way have an accu- 

 rate knowledge of the kind of milk which he is furnishing to 

 his customers, and he is able much more satisfactorily to con- 



FlG. 42. 



A B 



Fermentation tubes, showing method of testing gas-producing power. A, -growth of a 

 non-gas-producer; B, growth of a gas-producer 



trol the dairy processes. Quite a number of our modern 

 dairies thus keep a more or less careful record of the bac- 

 teriological condition of the milk which they produce. 



The examination of the public milk supply by the health 

 boards of our cities promises to be of considerable value in 

 the future, although up to the present time it has not been 

 made very extensively and, indeed, for reasons already 

 pointed out, the bacteriological examination has hitherto had 

 very little significance. As long as it is impossible to say how 



