PRACTICUMS. 
1. PasTEuRIzATION oF Mitx.—Secure fresh milk from clean and 
unclean stables, or prepare from the same milk clean and unclean 
samples. 
Pour in four small clean bottles or test tubes—eight in all—about 
one-half full with milk from each sample. Hold one bottle of each 
class of milk without further treatment at the temperature of the 
room. Now put the six remaining bottles or test tubes containing 
the milk in a vessel of water previously heated to 145 degrees. At 
end of three minutes remove one of each kind; in ten minutes one 
more of each kind; and at end of 20 minutes the other two, one of 
each kind. Now cool all the samples under test to a temperature 
of 65 to 70 degrees and leave these for future observation. What 
changes do you note in appearance after 24, 48 and 72 hours? 
2. MAKING THE Bascock TEst.— 
A simple Babcock testing outfit 
should be included in the regular 
equipment of every school. At 
different times during the school 
year, milk from all the neighborhood 
farms should be tested by the stu- 
dents themselves under the teacher’s 
direction. In this way it is possible 
for the school to determine the qual- 
ity of the milk of every cow of the 
FILLING THE BOTTLE neighborhood. d 
Proper position of holding the (a) Sampling the imilk.—Secure a 
pipette. sample from each cow of the herd 
as soon as milked. Pour the milk 
from one pail to another three or four times so as to get it thor- 
oughly mixed. Have clean bottles properly labeled with each cow’s 
name, one bottle for each cow. When the milk has been drawn and 
mixed, a sample is taken and emptied into the bottle marked for 
that cow. 
(b) Testing sample—Before the milk in the sample bottle is 
added to the testing bottles, it should be thoroughly mixed again. 
A milk pipette which accompanies the testing outht is used for 
securing the exact quantity. This amount is 17.6 cubic centimeters, 
and on this pipette is placed a mark showing just how much is to be 
sucked up into the tube. The pipette may be filled and then the 
milk allowed to drop out until the exact quantity is obtained. By 
firmly pressing the tip of the finger upon the top of the pipette the 
milk will be retained in it. Slightly releasing the finger will cause 
the milk to drop out until it reaches the mark indicated on the 
pipette. The point of the pipette is now placed in one of the test 
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