Bahcoch Test. 49 



Agricultural Experiment Station, and published in 

 Bulletin No. 8, February, 1890, of the Iowa Experi- 

 ment Station. In this test the solids of the milk 

 were destroyed by a mixture of acetic, sulphuric and 

 hydrochloric acids, and the fat brought to the sur- 

 face by boiling. The test was made in a flask with 

 a narrow graduated neck. A measured quantity of 

 milk was put in the flask, a sufficient amount of 

 the acids added, and the whole boiled for ten or fif- 

 teen minutes. The Iowa Station test was a great 

 improvement upon any that preceded it in point of 

 simplicity., accuracy and length of time required. 



Cochran^ s method. — This method was invented by 

 C. B. Cochran, of the Pennsylvania State Board of 

 Health, and published in the Journal of Analytical 

 Chemistry, Vol. III., page 381. In this method 

 the solids of the milk other than the fat were de- 

 stroyed by the use of a mixture of acetic and sul- 

 phuric acids, aided by boiling. When the milk 

 solids were thus completely disintegrated, the fat was 

 brought to the surface by the aid of ether, and then 

 the whole mass further boiled until the ether was all 

 evaporated. The clear melted fat was then meas- 

 ured by transferring it to a vessel with a gradu- 

 ated neck. The Cochran method was simple in 

 details, but required rather delicate manipulation in 

 transferring the melted fat from one vessel to an- 

 other. It, however, gave very good results in a 

 comparatively short time. 



The Bahcock test.— This test was invented by 

 Dr. S. M. Babcock, chemist of the Wisconsin Agri- 



D 



