174 THE OX AND THE DAIRY. 



tained in it ; and in this respect some breeds of cows are far 

 superior to others. The union of the component parts of milk 

 is chiefly mechanical, as they separate by subsidence according 

 to their specific gravities, the cream being the lightest, and the 

 curd the heaviest ; the curd, however, requires a slight chemi- 

 cal change for its separation from the whey, which at the 

 same time produces a peculiar acid called the lactic acid. 

 From the moment that milk is drawn from the cow it begins 

 to be affected by the air and changes of temperature, and cir- 

 cumstances almost imperceptible to our senses will materially 

 affect its quality : hence the importance of extreme care in 

 every step of the process of the dairy, especially in making 

 butter. 



The cows should be milked in the cool of the morning and 

 evening ; they should not be much driven immediately before 

 milking, and it is best to bring them to the place of milking 

 some time before the operation begins. In some situations 

 it is better to milk them in the pastures and carry the milk 

 home ; in others to drive the cows gently to the cow- stall. 

 In mountainous countries the first mode is generally adopted, 

 because the cows are apt to leap down steep places, and 

 shake the milk in their udder more than is done by carrying 

 it in the pail. The same practice holds good in Holland 

 from another cause, which is the distance of the pastures from 

 the home- stall, and the facility of transporting the milk in 

 small boats, all the best pastures being surrounded by 

 small canals communicating with the greater ; thus the milk 

 may be carried several miles without the least agitation. In 

 England, where the pastures frequently surround the habita- 

 tion of the dairyman, the cows are generally driven home 

 twice a-day, to be milked. As the slightest acidity or putres- 

 cence immediately causes an internal chemical action in milk, 

 it is of the utmost importance that the place where the cows 

 are milked, and the persons employed, should be of the 

 greatest purity and cleanliness. The milking-house should 

 be paved with stone or brick, and no litter or dung be per- 

 mitted to remain there. It should be washed out twice a-day, 

 immediately before each milking. The teats of the cows 

 should be washed clean with water and a sponge. 



As soon as the milk is brought into the dairy, it is strained 

 through a fine sieve or cloth, and it is then poured into 

 shallow pans or troughs lined with lead. The best pans are 

 of metal, either of iron, carefully tinned, or of brass. Such 



