88 BOARD OF AGRICULTURE. [Pub. Doc. 



tion where milk is liable to receive the most contamination. 

 The results show that the greatest source of contamination in 

 milk, as ordinarily produced, is the cow herself; and this is 

 doubly important, because it is the source which is given the 

 least attention in actual practice. 



The advantages of using covered pails with small openings 

 are apparent, from the fact that we have shown that one of 

 the most prolific sources of contamination is from the cow 

 and stable at the time of milking. When these small-topped 

 pails were first introduced into my own stables, the men 

 claimed that they could not milk into them ; but when one 

 of them was reminded that one of his diversions was milk- 

 ing into the mouth of a cat, sitting up on her hind legs, his 

 objection was readily overcome. One of the most interest- 

 ing experiments with small-top or covered pails was made at 

 the Connecticut station by Conn and Stocking. The milk 

 of one cow was drawn into an ordinary open pail one day, 

 and no extra precautions taken to exclude dirt or bacte- 

 ria. On the alternate day the cow's tail was tied to her leg, 

 the side, flank and udder washed with 3 per cent solution of 

 boric acid and wiped with a sterilized cloth. The milker 

 washed his hands with boric acid solution, and wiped them 

 with a sterilized cloth. When two teats had been milked, 

 the washinof of both the cow and the hands of the milker 

 was repeated, and the remainder of the milk was drawn 

 through four layers of sterilized cheese cloth and a layer of 

 absorbent cotton into a sterilized covered pail. In two series 

 of experiments the milk obtained under the extra precautions 

 to prevent contamination contained 267 and 242 bacteria per 

 c. c, as compared with averages of 3,888 and 3,116 respec- 

 tively Avhen no extra precautions were taken. When the two 

 kinds of milk were kept at 70° F., the milk obtained in the 

 ordinary manner curdled on an average in seventy-nine hours, 

 while the cleaner milk did not curdle until the end of one 

 hundred and thirteen hours. At this same temperature the 

 average increase of bacteria in thirty-six hours was thirty- 

 fold in ordinary milk, and tenfold in milk where aseptic 

 precautions had been taken. 



