508 EXPERIMENT STATION RECOKD. [Vol.36 



A polariscopic determination of sugar in " condensed milk,*' R. O. Brooks 

 (Jour. Indus, and- Engin. Chem., 8 {1916), No. 11, 1022-1024) .—The following 

 modified procedure is described : 



Fifty gm. of the well-mixed sample is diluted with water to exactly 100 cc. 

 and carefully shaken until completely dissolved. Exactly 26 cc. (13 gm.) is 

 pipetted into a beaker, diluted with water to about 40 cc, and Fehling's 

 solution added drop by drop with constant stirring until the proteins and fat 

 are precipitated. Usually about 1.5 cc. is sufficient. The mixture is then filtered 

 and the precipitate washed with water until the filtrate measures exactly 100 cc. 

 The filtrate is thoroughly mixed and a direct reading taken in a 200 mm. tube 

 of the polariscope at a temperature between 20 and 30° C. To exactly 50 cc. of 

 the filtrate 5 cc. concentrated hydrochloric acid is added, mixed, and allowed 

 to stand overnight at a temperature between 20 and 30°. The acid is exactly 

 neutralized with strong alkali, using phenolphthalein, and again very slightly 

 acidified with hydrochloric acid. It is then made up to 100 cc, filtered, and the 

 invert reading taken in a 200 mm. tube, as above. The direct reading is mul- 

 tiplied by 2 and the invert reading by 4, and the sucrose calculated by 

 Clerget's formula, using the factor 141.7 as follows : 



100 (Direct reading — Invert reading) 

 S-r«se= ,„,_.Te^„p. 



The procedure described is considered to be rapid and to yield accurate 

 results. 



A study of proteins in urine and a comparison of gravimetric and nephelo- 

 metric methods for their estimation, J. T. W. Marshall, H. W. Banks, 3bd, 

 and S. S. Gka\'es (Arch. Int. Med., 18 (.1916), No. 2, pp. 250-262).— A. nephelo- 

 metric method, using egg albumin as a standard for the determination of 

 protein in urine, and a formulative expression of the relation between the 

 light and concentration are submitted. 



It is concluded that " the nephelometric method is satisfactory for clinical 

 purposes, and that the results are in fair agreement with those obtained by the 

 gravimetric method. For urines of low protein concentration the method is 

 no doubt more accurate than the gravimetric. . . . 



"The nitrogen content of the protein recovered has been found to be lower 

 than the generally accepted values in the case of urine protein." 



An accurate aeration method for the determination of alcohol in fermenta- 

 tion mixtures, A. W. Dox and A. R. Lamb (Jour. Amer. Chem. Soc., 38 (1916), 

 No. 11, pp. 2561-2568). — The determination of alcohol by oxidation with 

 sulphuric acid and dichromate solution has been carefully studied. The best 

 results were obtained when the alcohol was determined by distillation and 

 titration of the acetic acid formed. 



A procedure in which the solution is saturated with ammonium sulphate 

 and the alcohol carried over into concentrated sulphuric acid by a current 

 of air is described. The alcoholic sulphuric acid solution is then mixed with a 

 solution of potassium dichromate, and the acetic acid distilled off at once. 

 The method has been used for the determination of alcohol in various kinds 

 of silage at the Iowa Experiment Station with very satisfactory results. 



The precaiitions necessary in the presence of interfering substances are dis- 

 cMssed. 



The distillation of cane sugar at the distillery of Oisemont (Somme), 

 fi. Saillakd (Compt. Rend. Acad. Agr. France, 2 (1916), No. 24, pp. 676-681).— 

 These pages briefly record the results of the use of molasses, beets, and apples 



