CARE OF THE MILK 99 



law that takes the filth to the outside of the separator 

 would prevent it rising with and into the cream. Its 

 tendency is downward. At the writer's suggestion 

 an experiment was made at one of our experiment 

 stations. This proved that gravity process cream is 

 as clean as that produced by the centrifugal process. 

 Gravity process carries less casein, ash, etc., into the 

 cream than the separator process. This discovery of 

 an improved gravity method of raising cream and 

 another in cream ripening, to be mentioned hereafter, 

 the writer considers as important advancements in 

 the art of butter-making. 



RIPENING OF CREAM 



Bacteria are the dairyman's best friends. The 

 science, or knowledge, of bacterial growth as ap- 

 plicable to the dairy has become a matter of prac- 

 tical utility at a comparatively recent date. 

 Thorough knowledge of it is, however, an important 

 branch of the dairyman's education. How to develop 

 and encourage the growth of the desirable, and 

 prevent the appearance of the undesirable, are im- 

 portant points for the dairyman to know. 



Bacteriologists inform us that germ growth in milk 

 is very rapid. Bacteria increase in geometrical ratio, 

 doubling their number under favorable conditions 

 several times every hour. Undesirable bacteria are 

 but another name for filth. Where they get the start 

 of the dairyman no prime dairy product can be made. 

 They abound in poorly kept stables and on unclean 

 cows. Hundreds of thousands of them drop into 

 the milk-pail from the teats, udder, and body of an 



