262 CITY MILK SUPPLY 



the financial loss which would ensue from selling milk from a high-testing 

 herd in competition with that of the low-testing herd of a rival. Detection 

 of the violation of such laws is not easy and their enforcement is difficult. 

 Perhaps it might be required to mark this standardized milk as "blended." 

 In some cities condensed milk is used in standardizing; the author would 

 regard this as an adulteration. It is said that milk powder is extensively 

 used for mixing up a milk to be used in blending and that it is very diffi- 

 cult to detect this practice. 



In Copenhagen the richness of the milk is plainly marked on the con- 

 tainers and the price of milk is based on the butterfat content. In the 

 United States this policy has not been adopted; it seems honest for it 

 allows the consumer to pay for what he wants and can afford. Some time 

 it may be adopted here but it is easy to foresee that the prejudice of cus- 

 tom will have to be overcome and that the delivery of milk of several 

 different grades from one wagon presents difficulties. 



Hinman has pointed out that this tendency of the large milk contrac- 

 tors to supply milk of uniform butterfat content tends to eliminate the 

 effect of the seasonal changes of the milk. Normally in the spring when 

 the cows go from grain feeds to pasturage there is a drop in the butter- 

 fat content of the milk which is followed by a rise to a point somewhat 

 above the summer average and that rise is succeeded by a drop to mid- 

 summer level after which there comes another rise to the high butterfat 

 content of winter and concentrated feeds. Analysis of the milk sold in 

 Indianapolis shows that in contrast to this condition which obtained 

 from 1906 to 1910, the butterfat from 1911 to 1913 remained practically 

 uniform throughout the year. 



In practice, milk is standardized by either increasing or decreasing 

 the percentage of butterfat in normal milk. It may be increased by 

 adding cream or a richer milk, or by skimming a portion of the milk and 

 returning the cream obtained to the rest. The butterfat content of milk 

 may be decreased without watering the milk, by adding milk poorer in 

 butterfat, or .skim-milk or by skimming part of the normal milk and add- 

 ing the skim-milk to the remainder. 



Pearson of the Cornell University Agricultural Experiment Station 

 suggested the use of the following diagram, a rectangle with two diag- 

 onals, in solving problems in standardizing. The tests of the milk or 



25 



17 



creams to be blended are written in the left-hand corners and the desired 

 test in the center, while in the right-hand corners are placed figures that 



