DAIRY FAEMING DAIRYING. 875 



Hence, as mixing is continually taking place, the milk in the receptacle can 

 give a positive reaction a considerable time (even several hours) after the 

 actual milk capable of causing the reaction has emerged from the pasteurizer. 



As the various milk particles probably have somewhat different temperatures 

 when they reach the top of the " universal pasteurizer," and the thermometer 

 can only register one temperature at a given moment, the latter must always 

 be higher than the critical temperature of the reaction (from 80° to 81°) in or- 

 der that the least warmed particles of the milk, and consequently the whole bulk 

 of the milk, shall not give a positive reaction. For this reason the maker now 

 makes a point of mentioning in the directions for using his apparatus that the 

 thermometer should always register at least 83° if the milk is to pass Storch's 

 test. It is thought that this precaution will be all that is needed, and the 

 working of the machine is not affected thereby. The rapidity with which the 

 milk cools after being heated seems to have no effect upon its reactive 

 capacity. 



The milk of .Jersey cows and of goats behaved in a precisely similar manner 

 to that of Danish cows in respect to its reaction to the Storch test. 



The control of the degree of acidity, the catalase, and the reductase by 

 biorization, W. D. Kooper {Molk. Ztg. [Hlldcshcim], 29 {1915), Nos. 76, pp. 

 959-961 ; 77, pp. 973, 974). — Data are presented which indicate that biorization 

 materially reduces the formation of acid in milk, destroys bacteria, and im- 

 proves the keeping quality of milk. 



Experiments in cheese making- from milks of different fat contents, A. V. 

 Lund {Brr. K. Vet. oy LandhnhdjsJ.-olcf! Lab. lAimlokonom. Forsoff [Copen- 

 hagcnl, 86 (1914), pp. 73-97; obs. in Infernaf. Inst. Af/r. [Rome], Mo. Bui. Agr. 

 Intel, and Plant Di.<ieases, 6 {1915), No. 7, pp. 988-990). — In cheese investiga- 

 tions it has been found that the coefficient of the cheese, i. e. the relation 

 between the fat content and the casein content, can be very accurately esti- 

 mated from tlie fat percentage of the " cheese milk " and, conversely, that the 

 fat percentage can be calculated from the coefficient. The factor to be used in 

 the case of the milk of ordinary Danish cows is 37.5. 



It follows that the coefficients of the different kinds of cheese known com- 

 mercially as whole-milk cheese, half and quarter whole-milk cheese, and skim- 

 milk cheese are sufficiently distinct to allow of the various kinds being distin- 

 guished by this means. In spite of the very considerable variations in the 

 values of the same sort of cheese it has been found that the minimum values 

 found for whole-milk cheeses are higher than the maximum values for half 

 whole-milk cheeses, while the minimum values for the latter are in their turn 

 higher than the maximum values of quarter whole-milk cheese, and so on. 

 Such factors as whether the cheese is made with pasteurized or unpasteurized 

 milk, and whether the curd is coarsely or finely divided, exert some influence 

 upon the coefficient of the cheese, but not to the extent of appreciably modifying 

 the above conclusions. 



The coefficients remain almost the same whether the cheese analyzed is fresh 

 or has been kept some time. The method of storing also has little effect upon 

 the coefficients as determined by analysis. As the coefficients determined by 

 the experiments are merely experimental figures, and do not correspond to the 

 conditions obtaining in practical cheese making, in trade, or at exhibitions, 

 they can not be used as type values, but may serve as guides for the determina- 

 tion of the latter. 



The yield of cheese can be roughly estimated when the amount of fat and 

 casein in the cheese milk is known. Cheeses made from the milk of Jersey 

 cows were found to have higher coefficients than those made from the milk of 



