no MILK AND DAIRY PRODUCTS PART 



'25 per cent, water 



Added water 



per 100 4Q 

 parts milk. 



Refractometer 

 number. 

 34-0 

 33-3 

 32-6 

 32-0 

 31-4 

 30-9 



Difference. 

 5-0 

 5-7 

 6-4 

 7-0 

 7-6 

 8-1 



Mai and Rothenfusser, 1 who, contrary to Henkel, 2 obtained 

 very good results with Ackermanri's method, give the following 

 detailed directions, when using the refractometer. Before taking 



FIG. 52. The Immersion Refractometer. 



the reading the beaker should stand for at least eight minutes 

 in a water-bath, having a temperature of exactly 1 7'5 C C. During 

 this time, and also during the reading, great care should 

 be exercised to keep every trace of water from the serum, for 



1 Molkerei-Zeitung, Berlin, No. 4, 1909. 



2 Ibid., No. 52, 1908. 



