126 Testing Milk and Its Products. 



whether or not the ripening process has reached the 

 proper stage for churning the cream. The apparatus 

 used (see fig. 42) is as follows: 



1 17.6 cc. pipette. 



1 white cup. 



100 cc. graduated cylinders ; it is well to provide two 

 or three of these, although only one is strictly necessary. 



137. Preparation of the solution. The tablet solu- 

 tion formerly used was prepared by dissolving five tab- 

 lets in 50 cc. of water ; with 20 cc. of cream each cubic 

 centimeter of this solution represents .017 per cent, of 

 acid (lactic acid) in the sample tested. The amount of 

 acid in a given sample is then obtained by multiplying 

 the number of cubic centimeters of the tablet solution 

 used, by .017. 



138. According to a suggestion made by Mr. C. L. 

 Pitch,^ the strength of the solution was changed in such 

 a manner that the percentages of acidity are indicated 

 directly by the number of cubic centimeters of tablet 

 solution used in each test. 



The 17.6 cc. pipette may be used for measuring the 

 sample for acidity testing, and the results read directly 

 from the graduated cylinder, if the tablet solution is 

 prepared by taking one tablet for every 19.5 cc. of 

 water; five tablets are therefore dissolved in 97 cc. of 

 water. 



139. As cream during its ripening process under the 

 conditions present in this country generally has from 

 .5 to .6 per cent, of acid before it is ready to be churned, 



• Hoard's Dairyman, Sept. 3, 1897. 



