11 



which it must be freed before it can be used again, else it would give 

 too high a reading. When the water-free reagent in bottle No. i has 

 been all, or nearly all, used up, the used reagent in bottle No. 2 can be 

 freed of moisture by filling the carefully cleaned evaporating cup with 

 it, attaching it to the condenser and heating until water ceases to drop 

 from the condenser tube. The drops of water are readily seen as they 

 sink through the reagent in the receiver. Now remove the cup and 

 empty its contents, which are free of moisture and ready for use, into 

 bottle No. 1. Put the reagent in the receiver into bottle No. 2, as it 

 contains moisture. 



Cautions. 



1. Always empty the reagent in the receiver, C, into bottle No. 2. 



2. Never use the reagent from bottle No. 2 for testing ; use only 

 that from bottle No. 1. 



To Test Curd and Cheese. 



The directions for testing curd and cheese are similar to those for 

 butter with the exception of the following : The sample is taken by pres- 

 sing the cylinder, mi, into the curd in the vat or into the cheese, as 

 the case may be, twisting it round and pulling it out. The sample will 

 be found in the cylinder. Be sure to obtain as representative a sample 

 as possible. The piston, m2, is now pressed in, thus forcing the sample 

 through the sieve on end of cylinder, mi. The sample should be pressed 

 through the sieve once more to reduce it to a fine state of division. Stir 

 the sample with the spoon and transfer it to the evaporating cup on the 

 balance, using five grams to a test. 



Use fifteen cubic centimeters of the reagent for curd and cheese 

 and add a small piece of paraffin wax to the cup to prevent the sample 

 from adhering to the bottom. After the test the curd or cheese is readily 

 removed by means of the spoon whose upper end is specially fitted for 

 this purpose. 



No great care need be taken in cleaning the cup after a test, since 

 it contains no moisture and can be easily balanced on the scale pan by 

 means of the counterpoise. Simply wipe it out with a dry cloth. 



Directions for Cleaning the Apparatus and Filling Condenser. 



The condenser need never be refilled with water unless several tests 

 are made in close order. In this case empty the condenser when it 

 becomes very warm about half way down and refill it with cold water. 



The inner condenser tube must be cleaned after every few tests, with 

 the flexible brush supplied. This should be run through the tube, first 

 in the dry condition and secondly moistened with the reagent. Use no 

 water in this operation. 



