NOTES. 497 



reduction method for nitrogen as nitrates (optional) be adopted as official. The 

 method for strontium and the colorimetric method for the determination of iodin 

 and bromin are to be further studied. 



A. S. Mitchell, associate referee on food adulteration, gave a r$sum§ of the 

 worli conducted on food adulteration .during the past year. W. E. Mathewson, 

 associate referee on colors, recommended that the methods described for the 

 qualitative separation of coloring matters be adopted provisionally and that 

 work bearing on the separation and identification of these substances be con- 

 tinued. 



A. H. Bryan reported on the proceedings of the Eighth International Com- 

 mission for Uniform Methods of Sugar Analysis, held in New Yorli September 

 10. The resolutions of the commission concerning the temperature of polari- 

 zation and the use of a neutral bichromate of potash light filter cell were 

 referred to the referee on sugar, W. E. Cross, for report at the next meeting. 

 Following a recommendation from the associate referee on saccharin products, 

 J. R. Chittick, the method for the determination of solids in molasses and other 

 sugar products, by means of the refractometer, using Geerlig's table of equiva- 

 lents and temperature corrections, but expressing the results as percentages 

 calculated from the refractometer readings, was adopted as a provisional 

 method. 



The associate referees on vinegar and flavoring extracts, W. A. Bender and 

 R, S. Hiltner, reported cooperative work in these subjects. A continuation of a 

 study of the refractive index of the ether extract of paprika with particular 

 regard for detecting added oils was reported by the associate referee on spices, 

 R. W. Hilts. He recommended that a method be devised for detecting an excess 

 of seeds in paprika and that samples of prepai-ed mustard be studied as to their 

 crude fiber content. E. Clark, as the associate referee on baking powders, 

 reported considerable difficulty in getting arsenic-free reagents for determina- 

 tion of arsenic in baking powders. 



The associate referee on meat and fish, W. B. Smith, reported on the study of 

 starch, ammonia, and nitrate determinations. He recommended that the Price 

 method for starch be substituted for the Mayerhofer method, and the Folin 

 method for the magnesium oxid method for estimating ammonia. 



H. C. Gore, associate referee on fruit products, reported results of studies 

 on the determination of malic and citric acid. With the Pratt method for 

 citric acid duplicates were hard to obtain, as tartaric acid when present in con- 

 siderable amounts seems to interfere. In the malic acid cooperative work the 

 results obtained agreed well. A study was also made of the optical rotation 

 of malic and tartaric acids, respectively, in the presence of vaiying amounts of 

 uranium acetate. 



As to fats and oils, H. S. Bailey, associate referee, reported the results of a 

 cooperative study of the glycerol method for the saponification of fats, and com- 

 pared various procedures with the official method. The provisional method for 

 the preparation of samples, the Zeiss butyro-refractometer method, method 12 

 for the determination of free fatty acids, the Halphen reaction for cotton-seed 

 oil, the Baudouin test for sesame oil, and the Yillavecchia test for sesame oil, 

 all as given in Bulletin 107, revised, of the Bureau of Chemistry, were adopted 

 as official. 



The Emery method for the detection of added beet fat in lard, and the gly- 

 cerin method for the preparation of fatty acids for use in the titer test, were 

 made provisional, as was also the use of 75° as the temperature for use in the 

 determination of the specific gravity of high melting-point fats. 



A. E. Paul, as the associate referee on dairy products, reported a further study 

 of his method for extracting fat from milk, cream, ice cream, evaporated milk, 

 and sweetened condensed milk. The associate referee on cereal products, 



