Testing the Acidity of Milk and Cream. 123 



solution to one measure of m,ilk contains less than .2 per 

 cent, of acid. 



By proceeding in the manner described, the man re- 

 ceiving and inspecting the milk at the factory weigh- can 

 is able to test the acidity of the milk delivered nearly as 

 quickly as he can weigh it; and according to the results 

 of the test he can send the milk to the general delivery 

 vat or to the pasteurization vat, as the weighing-can may 

 be provided with two conductor spouts. 



145. Size of measure necessary. It is not necessary to 

 use a No. 10 shell for a measure in working the preced- 

 ing method; one of any convenient size that can be filled 

 accurately and quickly, will answer the purpose equally 

 well, if a measure of the same size is used for both the 

 sample and the tablet solution. Each measureful of tab- 

 let solution made up as directed, will in this case repre- 

 sent one-tenth per cent, of acid in the sample tested. 



146. b, Cream. Cream can be tested in the way already 

 described for testing the acidity of fresh milk, by adding 

 to one measureful of cream in the cup as many measures 

 of tablet solution as are necessary to change the color of 

 the cream when the two liquids are thoroughly mixed. 

 If one measure of tablet solution colors one measure of 

 cream, this contains less than .1 per cent, acid; if five 

 measures of tablet solution are required, the cream con- 

 tains about .5 per cent, acid, etc. By proceeding in the 

 manner described, the operator can estimate the acidity 

 to within .05 per cent, of acid, if half measures of tablet 

 solution are added. The results thus obtained are suffi- 

 ciently delicate for all practical purposes. 



