FROM THE PRACTICAL VIEWPOINT 



practicable to heat milk to 145 and hold it for 

 thirty minutes with the machines in use in the city 

 without seriously affecting the cream line. Any 

 results and data secured do not warrant the con- 

 clusions that the experiments indicate the essential 

 superiority of any of the apparatus described. 



A little thought on the part of the reader will 

 make it clear that so many factors enter into the 

 problem that such conclusions would be unwar- 

 ranted. 



In the same way that percentages of bacteria 

 reduction mean little unless we possess all the 

 data connected with the handling of the milk, 

 so likewise percentages of cream upon pas- 

 teurized milk are not alone of ultimate value as 

 showing that one apparatus is more satisfactory 

 than another. 



A series of tests was made at several of the 

 pasteurizing plants in New York City at which 

 different forms of apparatus were being used, the 

 milk in these various plants being subjected to dif- 

 ferent degrees of temperature for varying lengths 

 of time. Samples of milk were taken to determine 

 the amount of cream which appeared upon the 

 bottled product. At the same time, the conditions 

 211 



