SECRETION AND CONTAMINATION OF MILK. 19 
tilth. As previously explained, such filth is an incubator for 
the kinds of bacteria that spoil the milk. Just before milking, 
the cow’s udder and flank should be dampened with a wet cloth 
or sponge to dislodge the dust and thus prevent its falling. The 
habit of wetting the teats, however, is a bad one, for dirt may 
be washed into the milk with the moisture. 
While a limited number of lactic acid-producing germs in 
milk may not be detrimental, the germs that come from barn 
filth are very injurious. 
35. Cooling the Milk. 
As soon as the milk has been aerated, it should be cooled 
to 60° F. or less. At 40° F. there will be little, if any, change 
in the milk, and if it has to be kept a considerable length of 
time, this temperature should be approximated as near as pos- 
sible. 
36. Covering the Cans. 
After the milk has been properly aerated and cooled, it 
should be covered to prevent evaporation from the cream that 
forms on the top. This cream can be readily worked back into 
the milk if it does not become leathery from evaporation. 
37. Kind of Utensils. 
Wooden pails should not be used for milk, for the reason 
that they cannot be easily and thoroughly cleaned; milk will 
soak into the wocd and ferment, ready to contaminate the next 
lot of milk. 
The seams of tin pails, cans and dippers should be filled 
flush with solder so that milk cannot collect and sour in crevices. 
38. Care of Utensils. 
All strainers, pails and other utensils in which the milk is 
handled should be rinsed first with lukewarm water, and then 
with koiling water, and if possible, exposed to a jet of steam to 
thoroughly sterilize them. Many germs are killed by direct sun- 
light, and the utensils should be set out in such a position that 
the sun can shine into them. After scalding they should not be 
wiped out with a towel or rag, as this would. be likely to again 
introduce undesirable germs in them. 
