SUPERVISION OF PRODUCTION AND MANUFACTURE OF MILK. 79 



likely to impair the quality of the cheese. If, on repetition of the 

 experiment within the next few days, similar results are obtained, and if 

 the quality of the cheese is unimpaired so long as this questionable milk is 

 excluded, it is quite justifiable to hold the supplier of the contaminated 

 milk responsible for any damage that may have arisen. 



Just in the same way as the milk-ferment test renders it possible to 

 trace milk contaminated with deleterious fungoid growths, the rennet test 

 renders it possible to detect milk which possesses unusual properties, and 

 which would exert a deleterious action in cheese-making. The rennet 

 test is applied in the same way as is done in testing the strength of 

 rennet, and consists in treating with rennet the milk which is being 

 investigated, and observing whether it coagulates quickly or slowly, or 

 whether it coagulates at all, and whether the coagulated mass obtained 

 possesses the ordinary properties. 



34. The Supervision of the Production and Manufacture of Milk. 

 In the supervision of milk production in country districts, all 

 that can be done is to take care that the cows are fed as suitably 

 and richly as circumstances permit, and that regular tests of the 

 milk are made as above described. This object will be attained if 

 similar quantities of butter are made from equal quantities of milk 

 obtained from a mixed herd of cows. As this is not always the 

 case, and as the average percentage of fat in the milk of cows 

 differs very much according to their surroundings, attention must be 

 paid not only to the yearly quantity yielded by each cow, but also 

 to the quality of the milk, in order to utilize the most valuable cows 

 for breeding purposes. Those that yield a less satisfactory return 

 ought to be removed, and in this way it will be possible gradually 

 to increase the yield of the entire herd. If sufficient attention has 

 not hitherto been paid to the quality of the milk, the neglect has 

 been chiefly due to the fact that a correct method for the determin- 

 ation of the percentage of fat, which could be carried out at once 

 rapidly and easily, and which was at the same time accurate and 

 reliable, was awanting. The Foser Lactoscope, formerly recom- 

 mended for this purpose, no longer satisfies present demands. Since 

 the lactocrit has been devised, however, and has been proved to be 

 as handy as it is reliable, a regular testing of the milk of single 

 cows for its percentage of fat, especially in large herds, is no longer 

 so very difficult to carry out. It is to be hoped that a reliable 

 method of determining fat will soon be discovered, so convenient 

 and at the same time so cheap that it may be capable of being 



