water has been removed,
the sample taken will show the same fat content as the milk used.
The samples taken previous to this will show a lower fat test,
dependent upon the relative amount of water and milk. In this
manner, the minimum, the maximum, and the average period of exposure
of milk in the machine tested, can be determined with exactness.

The accompanying table gives results that were obtained in the
testing of one of the continuous types of machines. The machine in
question required about three hundred pounds of milk to fill it and
was supposed to handle 1,000 pounds per hour. Thus theoretically it
should require twenty minutes for any portion of the milk to pass
through the machine. As will be seen from the data, some of the milk
passed through within seven minutes after the water was shut off and
the milk turned on. The figures also show that not all of the water
had been replaced by the milk in even 45 minutes. In actual practice
like results will be obtained, and a portion of the milk will be
heated to the temperature employed but a short time. In this, the
vegetating bacteria will not be wholly destroyed.

=========================================================
Trial | |Per cent of fat in milk coming from
| | machine at following times
|Per cent|---------------------------------------
| of fat| MINUTES
| in milk|---------------------------------------
| | 7 | 11 | 15 | 19 | 23 | 27 | 36 | 47
--------+--------+----+----+----+----+----+----+----+----
No. I | 4.0 | 0.2| 0.8| 1.6| 2.0| 2.4| 2.6| |
No. II | 3.8 | 0.2| 0.6| 1.5| 1.8| 2.2| 2.6| 3.0| 3.4
No. III | 3.5 | 0.7| 1.9| 2.4| 2.8| 2.8| 3.0| 3.4| 3.4
=========================================================

=Pasteurization of small quantities of milk.= It is often desirable to
treat a small quantity of milk for home use, in which case the
commercial types of pasteurizers are out of the question. This
treatment can be done in a number of ways, consideration always
being paid to the manner of heating which should be done under such
conditions, as have been shown to be necessary for efficient
pasteurization. Milk may be heated in tall, narrow cans which are
placed in hot water. In the household, milk may be treated by
placing the filled bottle in a pail having a false bottom so the
bottle shall not be broken when the pail is placed on