236 Testing Milk and Its Products. 



ficiently high to dry the cutter completely within an 

 hour, provided pans large enough to spread the butter 

 in a thin layer are used. 



If 10 grams of butter are used in making tests, a 

 more delicate scale is necessary than when 50 grams 

 are taken. There are other advantages in using as large 

 a quantity as 50 grams of butter for making tests of 

 water. First, a sample can be taken directly from a 

 package into a weighing pan. Second, ordinary tin 

 basins at least 5 inches in diameter can be used for dry- 

 ing the butter. Third, scales with a graduated side 

 beam and sensitive to .1 gram instead of those with 

 smaller locse weights can be used for weighing the but- 

 ter. (See fig. 35.) 



278. A practical method of estimating the salt content 

 of butter. A method of estimating the salt content of butter, 

 which is applicable also outside of chemical laboratories, has 

 been worked out jointly by Messrs. Alfred Vivian and C. L. 

 Fitch. 1 The salt of the butter is dissolved in hot water, and a 

 certain portion of the solution when cool is pipetted off and 

 titrated with a silver-nitrate solution prepared by dissolving one 

 silver-nitrate tablet in 50 cc. water,* potassium chromate being 

 used as an indicator. The silver nitrate tablets are sold for 60 

 cents per 100, which number is sufficient to make 100 to 150 tests. 

 The method has been advertised in the dairy press under the 

 name of " Fitch's Salt Analysis." Directions for making tests 

 by this method are furnished with the apparatus when this is 

 bought. The price of a complete outfit is $4.50. 



DETECTION OF ARTIFICIAL BUTTER? 



279. Determination of the specific gravity of the fil- 

 tered butter fat serves as a good preliminary test. A 

 number of practical methods for the detection of artifi- 

 cial butter have been proposed, but they are either 



1 Wls. experiment station, report 17, pp. 98-101; Hoard's Dairyman, 

 February 15, 1901, "Uniform Baiting of Butter." 



