CONVENTION OF OFFICIAL AGRICULTURAL CHEMI8TS. 429 



was recommended. The methods classified under the name of the cold 

 best were collected and studied. This test was defined as the coi 

 ing or solidifying point of an oil. The associate referee was inclined 

 to believe that the test used by Armour & Co. was the best of the 

 methods given and, if improved by the addition of time element. 

 would prove satisfactory. Unknown mixturesof lard and beef tallow 

 were sent out for cooperative work on the Belfield test, and the reports 

 of nine chemists were considered as indicating that where a satisfactory 

 method was u>ed. there was no difficulty in detecting additions of beef 

 tallow to lard. Further work was considered necessary before a -at 

 tsfactory method could he devised. The correction for temperature 

 with the refractometer, recommended in L903 (Bureau of Chemistrj 

 Huh 81, p. 64), was adopted as official, as was also the Hanus method. 



Dairy jrroducts. This report, by A. E. Leach, dealt with the exam 

 [nation of milk by means of the Zeiss immersion refractometer. A 

 minimum standard of 39 was adopted, below which it was considered 

 ■afe to allege that the sample was fraudulently watered, especially if 

 in addition to this the solids-not-fat were below 7.3 percent. Ana 

 jytical data, obtained by the associate referee, by R. B. Fit/ Randolph 

 of New Jersey, and by J. Hanle} r of Liverpool, England, were included 

 in the report. The refractometric method of Leach and Lythgoe for 

 the detection of water in milk was adopted as a provisional method. 



Cereal products.- No formal report was presented on the subject of 

 eereal products, but the associate referee, A. McGill, called attention 

 to certain physical tests used in the examination of dour, and recom- 

 mended further work. 



Cocoa iiml cocoa products. -A paper on cacao starch was read b\ 

 1). J. Howard. The author's studies were occasioned l>y statements 

 that it was possible to change cacao starch by heating in the process 

 of roasting into aggregates resembling other starches. He failed to 

 produce starchy masses resembling wheat and potato starch, and 

 lelieved that with tin 4 microscope, and more especially with the micro 

 iolari scope, the question of foreign starches in cacao products can be 

 ptablished, care being exercised to make sufficient micro-chemical 



tests to establish beyond a doubt that the masses under consideration 

 are starch and not fat globules. 



'/, ./ andcoffet . No cooperative work had been done during the year. 

 but II. ('. Lythgoe reported that the methods submitted at the last 

 convention had been used with marked success in the laboratory of food 

 ■id drug inspection of the Massachusetts State Board of Health for 

 the approximate quantitative determination of the ingredients of sam- 

 ples of adulterated coffee. 



Preservatives. — W '. D. Bigelow stated that analyses were made of a 

 number of products which had been canned with and without the addi- 

 tion of preservatives, the results of which showed that in no case where 



