PAYMENT OF MILK ACCORDING TO WEIGHT AND COMPOSITION. 311 



and if the above-mentioned values be given to A, F, f 1 , and R, the 

 result is as follow: 



(III.) / 2 = 6-667 x/- 1-4167, or 

 /2 = 5-773 xB. 



For calculating B from / or / 2 : 



B = 1-155 x/- -245, and B= -1732 x/ 2 . 

 For calculating / from B or / 2 : 



/= -886 x B + -2125, and /= -15 x / 2 + -2125. 



For calculating f 2 from / or B : 



/ 2 - 6-667 x/- 1-4167 and / 2 = 5'773 B. 



With the help of these formula, it is possible to calculate from any one 

 of the magnitudes F, /*, A, and E-, what the rest are. 



145. The Payment of Milk according to Weight and Composition. 

 Milk which is used for direct consumpt is sold at present, as is well 

 known, according to measure, and not according to composition. 

 Indeed, it is sold without any reference to its composition a fact 

 which is in the interest of the seller, but not in that of the pur- 

 chaser. On the other hand, milk which is destined to be worked into 

 milk products has been sold since about 1880 at so much per kilo- 

 gram, according to its composition. This arrangement has become, 

 from an economic point of view, all the more urgently desirable the 

 more the trade has improved, the keener the competition in the 

 production of butter and cheese has become, and the more convenient 

 the conditions are for the working of large quantities of milk. It 

 has only been adopted since the methods for the determination of 

 fat in milk have improved so much that the fat can be determined 

 in a short time, with all the accuracy that is required^ without the 

 aid of a chemical balance. 



The exact determination of the price of a kilogram of milk, 

 according to its composition, and the amount of substance it will 

 yield when converted into either of its bye-products, is very difficult, 

 and indeed hardly possible to calculate. The more accurately the 

 manufacture is conducted, the more trouble and expense has to be 

 incurred, and, when there is taken into account in this connection 

 economic considerations, one is forced to rest contented with obtain- 

 ing a good result without striving to reach the best possible. 



