New YorK AGRICULTURAL EXPERIMENT STATION. 1%" 
the tubes and according could not be expected to exercise 
fully its restraining influence on the bacterial life. 
In the preliminary work the placing of the tubes in the brine 
was intrusted to the men who had charge of the machines. 
An inspection of the tubes showed that they contained air in 
considerable quantities. Thereafter, the condition of the tubes 
was inspected by one of us before 10 o’clock of each day on 
which samples were to be coilected at the night milking and 
the air, which was practically always found in the tubes, was 
expelled. Simultaneously with this increased care there was a 
marked decrease in the fluctuation of the germ content of the 
milk although high counts were occasionally obtained as shown 
in the tables. 
Later, an attempt was made to measure the effect of allowing 
air to remain in the tubes. In this test the two machines 
which were used were supplied with cotton in the filter cups 
and were handled alike in all respects except that on each 
night two cows were milked with rubber parts in which the 
aid had purposely been inclosed while in the brine tank while 
the tubes used in milking the other two cows had been care- 
fully filled with brine after the preceding milking. Each cow 
was milked an equal number of times with tubes which had 
been handled in each of these ways. 
The resulting data are given in Table LV, 
