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BACTERIOLOGY. 
hands, and clean milk-pails. Immediately after the 
milk is drawn, it should be cooled to 5 0 C. (40° F.) 
and kept at this temperature until sold. 
The State Department of Health of New York, 
recognizing the importance of clean milk and the vari¬ 
ous purposes for which it is used, has established sev¬ 
eral grades of milk and cream with the requirements 
for their production. 
Grade A—raw milk. The cows must be tested 
with tuberculin at least once a year. Milk must not 
contain more than 60,000 bacteria per cubic centimeter 
and cream not more than 300,000 bacteria. 
Grade A—pasteurized. The number of bacteria 
per cubic centimeter must not be more than 30,000 in 
milk and 150,000 in cream. 
Grade B—raw. The number of bacteria must not 
exceed 200,000 per cubic centimeter in milk and 750,- 
000 in cream. 
Grade B—pasteurized. The number of bacteria 
per cubic centimeter must not exceed 100,000 in milk 
and 500,000 in cream. 
Grade C—raw and pasteurized have no limit 
placed on the number of bacteria. These grades are in¬ 
tended for special purposes. For infant feeding, 
Grade A raw or pasteurized should be used; for ordi¬ 
nary table use, Grade B raw or pasterized; and for 
cooking Grade C. 
Pasteurization is accomplished by heating the 
milk to 6o° C. (140° F.) for thirty minutes or 65° C. 
(158° F.) for fifteen minutes. The milk is imme- 
