64 CHEESE MAKING. 
136. Use of Acidimeter. 
At the present time the hot-iron test has teen largely super- 
seded by the acidimeter or the alkaline-tablet test. The use of 
the former test was first advocated by Prof. Dean ~f the Guelph 
Dairy School. This is the Manns’ acid test. (See Fig. 28.) 
Fig. 28.—The Manns’ 
acidimeter or acid test. Fig. 29.—The Marschall acid test. 
The apparatus consists of a 50 ¢. c. burette, a solution of phe- 
nolphtalein, a Babeock pipette, and a tenth-normal alkali solu- 
tion. When a pipette of milk or whey is used 1 ¢. c. of the alkali 
used is equal to .05 per cent of lactic acid. The Farrington 
tablet solution* may be substituted for the alkali solution. Use 
19.5 c. c. of water for each tablet. Each ec. c¢. of the solution 
used will be equal to .01 per cent of lactic acid. 
« “Testing Milk and Its Products,” p. 122. 
