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DIRECTIONS FOR TESTING MILK

The samples of milk to be tested by the Lactometer must
be brought to an equal degree of temperature, as any variation
of temperature will cause a difference in their specific gravity.
The Lactometers which are graduated for milk at 80 [degrees] Farenheit
are the most convenient for general use.

Whenever milk shows by the Lactometer a less specific gravity than pure milk, one of two things should be suspected:

[italics] First [/italics] - That the milk contains a greater amount of cream.
This can be easily determined by comparing it with an equal
quantity of pure milk, both being set in two equal Cream Gauges
a sufficient length of time for the cream to rise. It can then be
seen at once if the suspected milk contains as much cream as
the pure milk.

[italics] Second [/italics] - If it should be found to contain less, the inference
will be that the milk has been watered, and perhaps skimmed.

To ascertain how much water has been added, take a sample
of milk known to be pure and composed of a mixture obtained
from several cows, and put it in a Per cent Jar, filling the far up
to the gauge mark ten; then fill another Per cent Jar to the same
point with suspected milk, and the small jar with water to 0 or
zero. Place all three jars side by side, so that they will be of
the same temperature, and subjected to the same atmospheric
influences until the cream has time to rise.

Note the percentage of cream on each sample of milk before
removing it or disturbing it. After removing the cream from
both samples of milk, insert the Lactometer in the suspected
milk and note the point to which it sinks. Then place the
Lactometer in the pure milk and pour in water from the small
jar until the lactometer sinks to the same point at which it
stood in the watered milk. By examining the jar of water and
ascertaining the quantity taken from it and added to the pure
milk, the percentage o water in the suspected milk can be
determined.

[italics] Take notice [/italics] that the water jar, graduated from 0 to 100,
holds only one-half the quantity of the large jars, so that two
degrees of the small are equal to one degree of the large jar.
This must be considered when calculating the percentage of
water added. To prevent getting the large jars confused, one is
marked M. and the other P. M.

In all tests of milk care should be taken to render them
reliable, especially when affecting the reputation of the party
supplying it.