DAIRY METHODS 135 



milk spilled on the floor should be allowed to sour, but should 

 be washed up at once. Xo dairy is properly equipped unless it 

 has an ice supply. The amount of ice needed will vary with the 

 climate, being, of course, less in colder than in warmer regions. 

 For an ordinary climate at least 40 Ibs. of ice are needed for 

 every hundred pounds of milk produced. 



Cooling. The importance of cooling the milk, and cooling 

 it immediately, cannot be over-stated. As we have already seen, 

 bacteria grow very readily at a temperature of the animal's 

 body, very slowly at temperatures below 50 degrees, and scarcely 

 at all at the temperature of freezing. When the milk is drawn 

 from the animal it is, therefore, in a condition to stimulate the 

 growth of bacteria to its utmost. It is true that for a while, 

 because of the germicidal property of milk, the bacteria do not 

 grow; but this condition lasts only a short time, after which, 

 if the milk is warm, they begin to develop with the greatest 

 rapidity. If the milk, however, has been in the meantime cooled 

 to a low temperature, the bacteria that have found their way 

 into the milk will not grow rapidly, and the milk can be kept 

 for a very much longer period. These facts are so simple as 

 hardly to require statement, but, unfortunately, many a dairy- 

 man, although he may theoretically understand them, fails to 

 appreciate their importance. It not infrequently happens that 

 a milkman finds that his morning's milk sours when delivered 

 to his customers more quickly than milk of the night before, 

 and he has been puzzled over the matter. The reason usually 

 is that the night's milk, after milking, is placed at once in a 

 cool place, an ice chest or a cold stream, and by morning it has 

 acquired a fairly cool temperature. In the haste of the morning, 

 however, the milkman does not cool his morning's milk but car- 

 ries it to market in a warm condition. By the time it reaches 

 the customer the bacteria have begun to develop. In the mean- 

 time the milk of the night before has not been warmed up suf- 

 ficiently for the bacteria to begin to grow rapidly. Thus, the 



