312 SCIENCE AND PRACTICE OF DAIRYING. 



The first consideration in determining the utilization value of 

 milk is an exact knowledge of its solids. It is scarcely of any 

 practical value to obtain the composition of milk in all its constitu- 

 ents, since its value is almost entirely determined by its percentage 

 of fat and casein, and only to a slight extent by its mineral consti- 

 tuents. But even the determination of the caseous matter, in addition 

 to the fat, in order to estimate its value for the manufacture of fat 

 and skim -milk cheeses, is only of advantage in a few cases. It 

 involves far more than double the expense caused by the determina- 

 tion of the fat alone. At present, therefore, it is only customary 

 to obtain the percentage of fat in milk, and to calculate the value 

 from that. 



Obviously, if the selling price is to be determined in the dairies 

 of the different suppliers of milk by the percentage composition of 

 the milk, it will be necessary to estimate daily the percentage of fat 

 in each consignment, since it is only by this method that the true 

 average percentage in the milk of the different suppliers for the 

 period for which payment is made can be determined. This in 

 practice, owing to the great expense involved, is at present scarcely 

 feasible. For this reason, it is only customary to examine the milk 

 of each customer several times in a month for its percentage of fat, 

 and to calculate from the figures thus obtained an average value, 

 which obviously will not exactly agree with the true average value. 

 The oftener per month the investigations are undertaken, the nearer 

 will the true average value be arrived at; and the frequency with 

 which they are made depends on the degree of approximation which 

 those interested deem desirable. A periodical examination of the 

 milk should be made not less than once a week. 



If the amount of the average percentage of fat of the milk 

 obtained during the month from each supplier be known, as well as 

 the average percentage of fat in the whole quantity of milk worked 

 during the month, and if the question be how to fix a price for a 

 kilo, of milk from the different suppliers, and the monthly price to 

 be paid, several methods may be adopted, according as to whether, 

 as is the case in dairy companies, the question is as to the division 

 of a sum of money, or, as is the case with the dairy-farmer and the 

 owners of collecting dairies, the proper adjustment of the price to 

 be paid for the milk, to that of the price of the butter. We may 

 take the first case : 



(1) Payment of Milk in Dairy Companies in which Fatty Cheeses 



