90 Milk and Its Products 



the Kansas Agricultural Experiment Station, and 

 was published in the report of that station for 1888. 

 In it the solids of milk were destroyed by hydro- 

 chloric acid and the fat partially separated by means 

 of heat. The fat was then dissolved in gasoline, and, 

 after evaporation of the gasoline, was measured in 

 a graduated portion of the tube in which the opera- 

 tion was performed. It gave a clearer reading of 

 the fat than Short's method, but required more deli- 

 cate manipulation, particularly in heating the acid 

 and milk together and in evaporating the gasoline. 

 The time required was considerably less than with 

 Short's method. 



Parsons 7 method. This method was devised by 

 Professor C. L. Parsons, of the New Hampshire Ag- 

 ricultural Experiment Station, and published in the 

 report of that station for 1888. This method made 

 use of caustic soap and a solution of soap and alcohol 

 to destroy the milk solids, after which the fat was 

 dissolved in gasoline. A measured quantity of the 

 gasoline solution of fat was then taken, the gaso- 

 line evaporated from it and the fat carefully dried. 

 The free fat was then measured in a scale, and by 

 means of a calculation, the percentage of fat deter- 

 mined. This method gave very good results in the 

 hands of several different operators. It, perhaps, 

 required a little more delicate manipulation than 

 some of the others, and it was considerably more 

 complicated than Short's method. 



The Iowa Station test. This test was invented by 

 Professor George E. Patrick, the chemist of the Iowa 



