144 



MODERN METHODS OF TESTING MILK 



in the fruit- jar. Observe the precautions given above 

 in using tablet solutions. In making the test, put 

 17.6 cc. of the material to be tested in a teacup, pour 

 into the cup the alkali solution in the manner described 

 above, until the pink color remains. 

 Then pour the contents of the teacup 

 into the Spillman cylinder and read 

 the scale at the surface of the liquid 

 in the cylinder. The results indicate 

 the acidity in tenths of one per cent. 

 The cylinder reads as high as 8 tenths. 



Alkaline Tablet Test Modified for Ra- 

 pid Estimation of Acidity 



It is often desirable to ascertain 

 fc quickly whether milk or cream con- 

 FIG. 38^ tains more or less than .2 or .3 per 

 SPILLMAN'S ACID- cent, of acid. Farrington and Woll 



TEST CYLINDER , , , ,, n . ,, , 



have devised the tollowing method : 

 An alkali solution is prepared by dissolving in an 8- 

 ounce bottle 2 tablets for each ounce of water used. 

 A No. 10 brass cartridge shell, on which a wire handle 

 is soldered, is used for measuring the sample to be 

 tested and also the alkali. A cartridgeful of milk or 

 cream is placed in a teacup and then a cartridgeful 

 of the alkali solution is added. The contents of the 

 cup are mixed by a rotary motion. If the sample 

 tested remains white, it contains over .2 per cent, of 

 acidity ; if a pink color remains, the acidity is less than 

 .2 per cent. The intensity of the pink color indicates 

 the relative amount of acid present, since the color 



