34 
American Butter Factories. 
Means employed fob detecting diluted Milk. 
The most unpleasant feature of the factory svstem appears when 
dishonest patrons attempt to rob the Association by the delivery 
of watered milk. The Laws of New York are very severe on 
persons found guilty of this misdemeanor, punishing with heavy 
fines and imprisonment. The factory manager keeps watch over 
the milk as it is delivered, setting aside small quantities from 
time to time for observation and experiment with the hydrometer. 
Each factory is also provided with a set of small glass tubes, 
upon which the names of the patrons are pasted. As milk is 
delivered a small sample is placed in the different tubes cor- 
responding with the name of the patron, and set aside. If the 
milk is not all right, the hydrometer and these samples give 
warning ; the milk is then subjected to a more careful test, by 
the use of the cream-gauges and per cent, glass, which are repre- 
sented in the following figures : — 
In testing, one of the cream-gauges is filled to gauge-mark 10, 
with milk known to be pure, and drawn from several cows. 
This will be the standard for pure milk for that day. Another 
gauge is filled to the same number (10), with milk from a 
can which you wish to test. To avoid any mistake, the first jar 
containing pure milk is marked with the letters P. M. on the 
side or bottom. The jars are set away side by side, a sufficient 
length of time for the cream to rise. Now note the quantity of 
cream in each. If a less quantity is found on the milk you are 
testing than on the other, it indicates dilution, or skimmed milk. 
Now remove the cream from each with a spoon, introduce the 
hydrometer (or " lactometer," as it is usually called) into 
the jar marked P. M., and note on the scale-mark when it floats. 
Then remove it to the other jar, and note also when it floats. If 
it sinks lower than in the first jar, the evidence is considered 
almost positive of dilution with water. Replace the lactometer 
in jar marked P. M. from per cent, glass filled with water 
exactly to nought or zero ; pour into P. M. jar until the lacto- 
meter sinks exactly to the same point as in the other jar. Now 
count a number on per cent, glass from zero down (each mark 
represents one-half of one per cent.) and you will have precisely 
the percentage of water with which the milk you are testing has 
been diluted. 
Although there may be considerable variation in the specific 
gravity of milk from different cows, it has been found that when 
the milk of several cows is mingled together, and when the milk 
of different herds of a neighbourhood are compared, there is but 
little difference in the specific gravity of the several samples. 
These tests have been very effectual in bringing offenders to 
