70 Report of the Department ok Bacteriology of the 



alternately. After cleaning, the cows were so tied that they could 

 not lie down before being milked. The machine cleaning was done 

 under a vacuum usually slightly under 15 inches, or one-half an 

 atmosphere, while the hand cleaning was done with a brush and 

 curry comb, no water or damp cloth being used. The average 

 time consumed in cleaning a cow was approximately 66 seconds 

 with the machine and 33 seconds by hand. 



The pails and their protection, the sampling and the examination 

 of the samples were all in accord with the description given under 

 the head of Technique (page 53). Four plates were made using 

 dilutions of 1 to 2 and 1 to 10. 



The first test was made during October, 1911, and included 88 

 samples of milk. The germ counts obtained from these samples 

 are given in Table XIII. 



Table XIII. — Bacteria in Milk from Cows Cleaned by Hand or by Vacuum 



Cleaner. 



It is seen from the above table that the results from Gertie F. 

 No. 2 are extremely low on both sides of the comparison and that 



