Chemical Analysis of Milk and Its Products. 241 



too low results and, therefore, not to be preferred to 

 the Babcock test for cheese (105). 



287. c. Casein (total nitrogenX6.25). About 2 grams 

 of cheese are weighed out on a watch glass and trans- 

 ferred to a Jena nitrogen flask, and the nitrogen in the 

 sample determined according to the Kjeldahl method 

 (253) ; the percentage of nitrogen multiplied by 6.25 

 gives the total nitrogenous components of the cheese. 



288. d. Ash. The residue from the water determina- 

 tion is taken for the ash ; it is preferably set fire to, in 

 the same manner as explained under determination of 

 ash in butter (270), before it is placed in the muffle 

 oven and incinerated. The increase in the weight above 

 that of the empty dish-f-asbestcs, gives the amount of 

 ash in the sample weighed out. 



289. e. Other constituents. The sum of the percent- 

 ages of water, fat, casein and ash, subtracted from 100, 

 will give the per cent, of other constituents, organic 

 acids,- milk sugar, etc., in the cheese. 



DETECTION OF OLEOMARGARINE CHEESE ("FILLED" 

 CHEESE. ) 



290. About 25 grams of finely-divided cheese are ex- 

 tracted with ether in a Caldwell extractor or a paper 

 extraction cartridge; the ether is distilled off, and the 

 fat dried in the water oven until there is no further 

 loss in weight. 5.75 cc. of the clear fat are then meas- 

 ured into a 250 cc. saponification flask and treated ac- 

 cording to the Reichert-Wollny method, as already ex- 

 plained under Detection of Artificial Butter (282). 1 



i:See : Arb. Kals. Ges.-Amt., 14, 506-598 

 6 



