TESTING DAIRY PRODUCTS BY THE BABCOCK TEST. 91 



settle to the bottom of the jar. The contents of the pipette is 

 then run into the bottle, the jar shaken again and more 

 butter taken up and run drop by drop into the bottle until the 

 scale turns. Remove the bottle from the scale and add 9 cubic 

 centimeters of hot water and 10 cubic centimeters of sulfuric 

 acid, (1.82 specific gravity), mix thoroughly, place in the centri- 

 fugal machine and whirl a few minutes at usual rate. Then 

 take the bottle from the machine, connect the neck by a piece 

 of rubber tubing and stand the whole in a tank of water heated 

 to no° to 120 F., sufficiently deep to allow the water to come 

 up to near the 90 per cent mark. Now fill the bottle to near 

 the 87 per cent mark with hot water and let it stand several 

 minutes before reading. The reading is taken the same as on 

 the milk or cream bottles. 



TESTING CHEESE. 



How to take the Sample. Where the cheese can be cut, a nar- 

 row wedge reaching from the edge to the centre of the cheese 

 will more nearly represent the average composition of the 

 cheese than any other sample. This may be chopped quite fine, 

 with care to avoid the evaporation of water, and the portion 

 for analysis taken from the mixed mass. 



When the sample is taken with a cheese tryer, a plug taken 

 perpendicular to the surface, one-third of the distance from the 

 edge to the centre of the cheese, should more nearly represent 

 the average composition than any other. The plug should 

 either reach entirely through or only half through the cheese. 

 For inspection purposes the rind may be rejected, but for 

 investigations where the absolute quantity of fat in the cheese 

 is required, the rind should be included in the sample. It is 

 well when admissible, to take two or three plugs on different 

 sides of the cheese, and after splitting them lengthwise with a 

 sharp knife take portions of each for the test. 



Making the Test. For the estimation of fat in cheese, 6 grams 

 should be carefully weighed out in a cream test bottle. Twelve 

 cubic centimeters of hot water is then added, and the bottle 

 shaken at intervals, keeping it warm, until the cheese has 

 become softened, and converted into a creamy emulsion. This 

 may be greatly facilitated by the addition of a few drops of 



