98 MODERN METHODS OF TESTING MILK 



pour the contents of the teacup into the Spilhnan cyl- 

 inder and read the scale at the surface of the liquid 

 in the cylinder. The results indicate the aciditv in 

 tenths of one per cent. The cylinder reads as high as 

 8 tenths. 



TABLET TEST MODIFIED FOR RAPID ESTIMA- 

 TION OF ACIDITY 



It is often desirable to ascertain quickly whether 

 milk or cream contains more or less than .2 or .3 per 

 cent, of acid. Farrington and Woll have devised the 

 following 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 meas- 

 uring 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 pres- 

 ent, since the color will be more intense in proportion 

 as there is less acid. Any other measure may be used 

 in place of the brass cartridge-shell, b;it in every case 

 care must be taken to use equal amounts of milk or 

 cream and of alkali solution. 



