SEPARATOR CREAM. 187 



In his investigations of tuberculous milk Bang did not 

 succeed in purifying it entirely from bacilli by means 

 of the centrifuge. I also have been unable to remove all 

 bacteria from milk infected with the ordinary milk bac- 

 teria by means of separation. If we cannot obtain milk 

 free from bacteria by the use of centrifugal force as ap- 

 plied in our ordinary separators, it does not follow that 

 the decrease in the bacterial content of the milk before 

 spoken of is of little importance. In case of infectious 

 bacteria, as in Bang's investigations, the results proved 

 on the whole of small account, as milk but slightly 

 tuberculous must be considered injurious to health. But 

 the matter is quite different in case of fermentation bac- 

 teria: the fact alone that their number is decreased by 

 the separation makes this method decidedly better than 

 all other methods of cream-separation now known. 



The cream having been freed from a large number of 

 its bacteria in the separator process, we must see to it that 

 the advantage gained is not lost through bad treatment. 

 The danger is here great from the beginning, as the tem- 

 perature of the newly-separated cream is very favorable to 

 the development of the bacteria, the temperature of the 

 milk when separated being usually about 86 F. (30 0.). 

 We cannot therefore be surprised that the cream will soon 

 be filled with a large number of bacteria if its temperature 

 is not rapidly lowered. 



As both the cream and the skim-milk come from the 

 separator in thin streams they offer a large surface of in- 

 fection, and it is therefore absolutely necessary not to 

 allow dirty or dusty persons to approach the separator; 

 this is, however, permitted to pass unnoticed in many of 

 our creameries. The air in the separator-room must for 



