342 CHEMICAL TESTS AND ANALYSES 



densed milk to contain 40 per cent sucrose when the milk has been 

 condensed sufficiently to contain 32 per cent milk solids? 



Answer : 32 : 40 = 12 : X : X = 15. 



To every 100 pounds of fluid milk must be added 15 pounds 

 of sugar. 



To 15,000 pounds fluid milk must be added 



15 X 15,000 _ 

 = 2250 pounds of sucrose. 



CHAPTER XXX. 



CHEMICAL TESTS AND ANALYSES OF MILK, SWEET- 

 ENED CONDENSED MILK, EVAPORATED MILK 

 AND MILK POWDERS. 



In assembling these methods of analyses, preference has 

 been given the "Official and Provisional Methods of Analysis," 

 published by the American Association of Official Agricultural 

 Chemists. 1 The official methods have been modified and supple- 

 mented by other methods in numerous cases wherever, in the 

 judgment of the writer and others, such modifications and sub- 

 stitutions are better adapted for analysis of these special prod- 

 ucts. A special effort has further been made to include in this 

 chapter modifications and abbreviations of tests and analyses, 

 adapted for the use of the factory operator, whose knowledge, 

 skill, facilities and time are too limited to enable him to success- 

 fully follow the directions of the official methods, or to execute 

 delicate and difficult chemical analyses. 



For practical factory tests of fresh milk on the receiving 

 platform, determining its fitness for condensing, the reader is 

 referred to Chapter III, "Inspection of Milk at the Condensery." 



MILK. 



Specific Gravity. 



Aerometric Method by Means of the Quevenne Lactometer. 

 Use an accurate Quevenne lactometer with thermometer at- 

 tachment and a lactometer cylinder about ten inches high and 



1 United States Department of Agriculture, Bureau of Chemistry, Bulletin 

 No. 107, 1912. Also Journal of the Assn. of Official Agr. Chemists, Vol. II, 

 No. 3, Nov. 15, 1916. 



