AGRICULTURAL CHEMISTRY — AGROTECHNY. 807 



111-116). — An improvement of the method described by Stepanoff" and 

 modified by others is outlined in detalL 



The method consists in dissolving the halogen compound in 98 per cent 

 alcohol, adding an excess of sodium and, after sufficient heating, diluting the 

 mixture with water. The alcohol is then distilled off, the solution acidified 

 with nitric acid, and the free halogen acid, thus produced, titrated according 

 to Volhard's method. Experimental data submitted indicate the accuracy of 

 the method. The qualitative procedure was found to yield a decided positive 

 test in certain cases where the Beilstein test gave a doubtful result. 



A method for the estimation of chlorids in cheese, Elfreida G, V. Cobnish 

 and J. GoLDiNG {Analyst, 40 (1915), No. 470, pp. 197-203, fig. 1; abs. in Ztschr. 

 Angeic. Chcm., 29 {1916), No. 2, Referatenteil, p. 4). — A method claimed to be 

 more accurate and rapid than the incineration or water-extraction method I3 

 described. 



The sample is treated in a Kjeldahl flask with concentrated sulphuric acid 

 and gently heated. By means of a specially arranged apparatus tlie hydro- 

 chloric acid formed by the action of the sulphuric acid on the chlorids present 

 is aspirated into standard acid silver nitrate and precipitated as silver chlorid. 

 When the reaction is complete the silver chlorid is filtered, washed free of 

 nitrates, the washings added to the filtrate, and the excess of silver nitrate in 

 the filtrate determined according to Volhard's method. Experimental data, 

 obtained from different samples of normal cheese and others showing a brown 

 discoloration are submitted. 



The cheese residue remaining in the flask after the distillation of the hydro- 

 chloric acid may be used for the estimation of nitrogen in the solid cheese, by 

 Kjeldahl's method. 



The determination of acidity in potatoes, J. F. Hoffmann and F. Pkeckel 

 {Landw. Vers. Stat., 87 {1915), No. 2-3, pp. 237-239) .—The following procedure 

 is recommended by the authors : 



Fifty cc. of the pressed juice is measured into a 250 cc. flask, and 95 per cent 

 alcohol added to the mark. The mixture is allowed to set for about one hour 

 with occasional shaking and then filtered. For the titration 100 cc. of the 

 filtrate is diluted with an equal volume of water and 1 cc. of rosolic acid 

 added. The liquid thus contains about 80 cc. of alcohol and 120 cc. of water. 

 A comparison solution is prepared in a similar manner with 80 cc. of alcohol 

 and 120 cc. of water and titrated to a definite color change. The potato sample 

 is titrated to the same shale and the reading of the comparison solution sub- 

 tracted from that of the potato sample. The liquids should be well shaken 

 before titrating in order to remove as much as possible of the carbon dioxid, 

 which influences the color change. 



The analysis of maple products. — V, Miscellaneous observations on maple 

 sirup incidental to a search for new methods of detecting adulteration, J. F. 

 Snell {Jour. Indus, and Engin. Chem., 8 {1916), Xo. 2, pp. l^-l^S). — Certain 

 observations made while working on new methods for the detection of adultera- 

 tion are recorded. A complete ash analysis of a composite of about 60 genuine 

 sirups indicated the presence of more chlorin and less phosphoric acid than the 

 analyses previously recorded. 



See also previous notes (E. S. R., 32, p. 808; 33, pp. 15, 208). 



The determination of small amoiints of sug'ar in urine, S. Nagasaki 

 {Hoppc-Seylefs Ztschr. Physiol. Chem.. 95 {1915), No. 2-3, pp. 61-77). — For 

 determining small amounts of sugar in urine the author has devised a method 

 . as follows : 



" Ber. Deut. Chem. Gesell., 39 (1906), No. 16, pp. 4056, 4057. 

 41852°— No. 9—16 2 



