ORGANIC ANALYSIS 509 ORGANIC ANALYSIS. Detection of Acetone by Frommer’s Test. N. 0. Engfeldt. ( B e d . klin. Woch., 1915, 52,458-459 ; through Chem. ZentraZbl., 1915, ii., lOO.)--Frommer’s test depends on the formation of a red-coloured compound when acetone is condensed with salicylaldehyde in the presence of alkali hydroxide. To detect acetone in urine, 10 C.C. of the latter are treated with 1 grm.of solid potassium hydroxide and, without waiting for the latter to dissolve, 10 drops of 10 per cent. salicylaldehyde solution (in alcohol) are added, and the mixture is heated to 70’ C. Should acetone be present, a purple-red zone develops at the junction of the two liquids; 0.05 mgrm. of acetone in 10 C.C. of solution may be detected in this way. The author finds that the reaction may be made more sensitive and capable of detecting 0001 mgrm.of acetone per 10 c.c., by mixing 10 C.C. of the urine distillate with 5 grms. of solid potassium hydroxide and 5 drops of concentrated salicylaldehyde solution in a test-tube, placing the latter in a water bath at 50” C., and heating the water gradually to boiling. As the potassium hydroxide dissolves, a crystalline mass is formed which is coloured bright-red, if acetone is present.Acetoacetic acid and hydroxybutyric acid also yield red compounds with the teat, but formaldehyde, wetaldehyde, formic acid, lactic acid, phenols, and alcohol do not interfere. w. P. s. Acid Potassium and Acid Sodium Phthalates as Standards in Acidimc- try and Alkalimetry. W. S. Hendrixson. (J.Amer. Chew. Soc., 1915, 37, 2352-2359.)-The use of the acid phthalates as standards for volumetric solutions was advocated by Dodge (ANALYST, 1915, 171) on account of the ease with which they are prepared in a stable, pure, and anhydrous form. The author has made a comparative investigation of vtqrioup methods of stsndardisation, using all pre- cautions, by means of weight-burettes, to secure the highest degree of accuracy in measurement.A standard solution of hydrochloric acid was thus prepared, based on the distillation of an acid of constant composition by the method of Hulett and Bonner (ANALYST, 1909, 34, 239). Titrations were made against a solution of pure sodium hydroxide in a current of air free from carbon dioxide in presence of phenol- phthalein, the alkali being run into the acid. All results were obtained in terms of weight, being calculated in terms of C.C.from determinations of specific gravity. The hydrochloric acid solution, prepared from the acid of constant boiling-point, was c a h l a t e d to contain 0.0036470 grm. per 1 C.C. Standardised gravimetrically as510 ABSTRACTS OF CHEMICAL PAPERS silver chloride, it showed 0.0036497 grm.Standardised by titration, it showed against benzoic acid (two preparations) 0*0036510 and 0.0036497 grm. ; against acid potassium phthalate 0.0036495 and 0.0036484 grm. ; against acid sodium phthalate 000036494 grm. Average of seven standardisations, 0.0036492 grm. Hence it follows that either of the phthalates may be used with a greater accuracy than is imposed by the limitations of the best volumetric apparatus.Acid potassium phthalate crystallises readily from water in the anhydrous form ; it is prepared by treating pure sublimed phthalic anhydride with slightly more than the calculated quantity of pure potassium carbonate, and recrystallising five times from hot water. The salt is dried in the oven for several hours, and its constancy in weight confirmed.Acid sodium phthalate is prepared in an analogous manner; it crystallises with ,tH,O, but is completely dehydrated without decomposition on heating at 120' C. to constant weight. J. F. B. New Colour Reaction for Papaverine. L. E. Warren. (J. Amr. Chem. SOC., 1915, 37, 2402-2406.)-By treating papaverine ferricyanide with Marquis's reagent (sulphuric acid containing a little formaldehyde), a blue colour is produced, which passes through violet and green stages to a dirty brownish-yellow. Sub- &antially the same reaction is observed by treating a mixture of the alkaloid and potassium ferricyanide with Marquis's reagent, but in this case the initial tint is greenish-blue.Many other oxidising reagents may be used instead of the ferri- cyanide, the shades of colour produced varying with the reagent employed.The reaction is best observed by intimately mixing a very small quantity of an oxidising agent, such as cerium oxide, phosphomolybdic acid, or potassium permanganate, with a very small quantity of papaverine, and stirring the mixture with a few drops of sulphuric acid containing a little formaldehyde. Of thirty-nine alkaloids tested, only one (an alkaloid from sanguinaria) gave colours in any way resembling those produced with papaverine.By using selenious acid as the oxidising agent, the sanguinaria alkaloid may be differentiated, giving an initial reaction of intense purplish-violet instead of a fugitive greenish-blue changing to deep blue, as with papaverine. J. F. B.Estimation of Total Sulphur in Rubber Products. A. Hutin. ( A m Chim. anal., 1915, 20, 214-216.)-From 1 to 2 grms. of the sample is treated with 30 c.c.of fuming nitric acid, added in successive portions of 2 to 3 c.c., and the mixture evaporated to a syrup on the water bath, and treated drop by drop with 2 to 3 C.C. pure sodium hydroxide solution. The alkaline liquid is then mixed with sufficient calcined magnesia to make a thick paste, evaporated to dryness at 140' C., and cautiously heated so as to avoid ignition of the mass. The friable residue is heated and stirred with water on the water bath, aud the extract and washings (about, 300 C.C. for 1 grm. of material) filtered, concentrated to 100 c.c., and acidified with hydrochloric acid, the carbon dioxide expelled, and the sulphuric acid precipitated with barium chloride. The final solution ought to be colourless, any coIoration indicating that the ignition was incomplete. C. A. M.