127 



(or butter), should show whether the minimum temperature 

 of 176 had been applied. 



Prof. V. Storch devised the following simple test: 

 A teaspoonful of the milk (cream or whey) to be tested is 

 poured into a test tube and one drop of a solution of hydro- 

 gen superoxide and two drops of a solution of Paraphenylen- 

 diamin is added and the milk shaken. If the milk immediate- 

 ly becomes strongly colored (milk and cream indigo blue, 

 whey violet reddish brown) then it has either not been "heated 

 at all or has not been heated over 172. If the milk assumes 

 a bluish gray color at once or within ^ minute, then it has 

 been heated to between 174 and 176. 



If sour buttermilk is to be tested half a teaspoonful of 

 clear lime water is mixed well with it before adding the chem- 

 icals, and if a blue color does not show it is proof that the 

 milk or cream from which the buttermilk came has not been 

 heated to 176. 



Butter is tested by weighing about 25 grams which is 

 melted in a suitable beaker in a water bath of not over 140. 

 After separating the clear oil, the sediment (brine and butter- 

 milk) is mixed with about an equal quantity of water, and 

 this mixture is treated as before described. 



The solutions are prepared as follows: 1 gram Para- 

 phenylendiamin is dissolved in 50 grams warm (distilled) 

 w r ater, is filtered through filtering paper and preserved in a 

 brown glass bottle. It is safest to keep the solution in a cold 

 place. As a rule it will be useless in two months. The com- 

 mercial solution of Hydrogen superoxide is as a rule stronger 

 than needed. If it contains about 1 per cent it may be diluted 

 five times its volume, with water to which has been added 1 

 cc concentrated sulphuric acid per quart. This diluted solu- 

 tion is also preserved in brown glass bottles. 



FILTERED WATER AND LONG KEEPING BUTTER. 



I have again and again emphasized that the pasteurizing 

 of the cream for buttermakers is only to be recommended. 

 (1) At creameries where, in spite of all precautions, the milk 

 delivered is "off," has weedy or other bad flavors. (2) At 

 creameries where it is known that the butter is to be exported 

 or even held for long cold storage. While there may be ex- 



