34 Report oF THE BACTERIOLOGIST OF THE 
cheese of the following day was examined after the necessary 
interval no spots were found. The occasional boiling of the mill 
was continued, but the spots in the cheese again became plentiful. 
The red points were abundant in all the cheese made between 
June 25 and July 8. In the cheese of the latter day the points 
were very closely set, and could be readily seen by the ordinary 
observer. 
After the cheese was in press on July 3 the curd mill, knives, 
rakes, conductors and everything which came in contact with the 
milk were put into the vat, covered with water and heated with 
steam. It took two hours to heat this water to 160° F. and con- 
sumed a large amount of steam. The process had the further 
disadvantage that the hot water tended to warp the wooden 
utensils. The weigh can and remaining vats were heated with 
direct steam. 
This heating was repeated on July 12, except that the water 
was left out of the vat and the utensils were heated with direct 
steam. In doing this a heavy cloth cover was drawn over the 
vat to retain the steam, and the temperature was raised to 180° F. 
and held there 15 minutes, so that the heat would penetrate all 
portions of the tools. The consumption of steam, while consid- 
erable, was far less than when the water was used and the heating 
of a vat full of tools could be completed in 20 minutes. 
The effect of this treatment upon the cheese was prompt and 
satisfactory. The cheese made July 4 contained less than +> 
as many red points as that made the preceding day and these red 
points remained small and hard to find at the end of 12 days. 
While the activity of the germs was checked by this heating, 
they were not all removed, and in the succeeding days the spots 
appeared in varying numbers, but it was only in the cheese of 
July 12 that they were recorded as large enough to be easily seen. 
As it chanced, the second steaming occurred immediately after 
this cheese was made; and ten days later only a few points could 
be found in the cheese made July 18. 
In connection with our work we made a number of trips to the 
factory to observe the treatment in operation, to compare ideas 
with the factorymen and to examine the cheese upon the shelves. 
