36 Dairy Bacteriology. 



Milking machines and farm separators. The intro- 

 duction of these special types of dairy machinery in the 

 handling of milk on the farm has materially complicated 

 the question of the care of milk. Both of these types of 

 apparatus are much more complicated than the usual 

 milk utsensil; consequently, the danger of imperfect 

 cleaning is thereby increased. This is still further ac- 

 centuated by the fact that cleansing of utensils on the 

 farm can never be done so well as at the factory or milk 

 depot where steam is available. The milking machine 

 may be easily kept in a comparatively germ-free condi- 

 tion, but unless this is done, it contributes its quota of 

 germ life to the milk. 



The farm separator is more widely used than the milk- 

 ing machine and in actual practice the grossest careless- 

 ness prevails in the matter of its care. Frequently it is 

 not taken apart and thoroughly cleansed, but is rinsed 

 out by passing water through the machine. It is impos- 

 sible by such a treatment to remove the slime that col- 

 lects on the wall of the bowl ; the machine remains moist 

 and bacterial growth can go on. Such a machine repre- 

 sents a most important source of contamination of milk 

 and cream and it is probable that the widespread in- 

 troduction of the hand separator has contributed more 

 to lower the quality of cream delivered at the factory 

 than any other single factor. 



Contamination from factory by-products. The cus- 

 tom of returning factory by-products in the same set of 

 cans that is used to bring fresh milk is a prominent 

 cause of bad milk. "Whey and skim milk are rich in bac- 

 terial life, and not infrequently are so handled as to be- 

 come a foul, fermenting mass. If the cans used to trans- 

 port this material are not scrupulously cleaned on the 



