METHODS OF TESTING BUTTER FOR WATER 115 



weight of the sample used and multiply the result by 

 100. For example, a ic-gram sample after evapora- 

 tion of water weighs 9 grams ; the difference (i gram) 

 is the amount of water, which is 10 per cent, of the 

 butter sample tested. The arithmetical operation is 

 indicated as follows: \ 



i (weight lost in grama) -f- 10 (amount of sample 

 in grams) x 100 = 10 (thjp^ef cent, of water in the 

 butter). In case of a 5O-gram sample, which loses 

 7 grams of water, welfare the following: 7 -7-50 x- 

 100= 14 (the per cent, of water in butter). 



CORNELL TEST FOR WATER IN BUTTER 



This was devised by Ross at the Cornell University 

 experiment station. The apparatus required includes 

 (i) an alcohol lamp; (2) a cast aluminum cup or 

 beaker for holding and heating sample. (A conve- 

 nient size for this and similar tests is about 3 inches 

 high and 2 inches in diameter); (3) an iron stand; 

 (4) a thin sheet of asbestos; (5) a hand-clamp for 

 lifting the cup. While any balance or scale of sufficient 

 delicacy can be used, Ross recommends as most con- 

 venient a special form (Fig. 31 a, p. 79) which en- 

 ables one to calculate the results on the arm of the 

 scale; this scale is well adapted for cream-testing also. 

 The distinctive feature of this method is mainly the 

 use of asbestos between the dish and flame. 



The operation is carried out as follows : The sample 

 of butter (20 grams) properly prepared (p. 101) is 

 weighed into the clean, dry aluminum cup, the weight 

 of which has already been found. The alcohol lamp is 



