$OOD AND DRUGS ANALYBIS 319 ABSTRACTS OF PAPERS PUBLISHED IN OTHER JOURNALS. FOOD AND DRUGS ANALYSIS. Presence of Aconitic Acid in Sugar-Cane Jnfee, and New Reaction fop the Deteotion of the Acid. C. S. Taylor. (J. Cbm. Soc., 1919,115,886-889-)- The presence of aconitic acid in sugar-cane juice was inferred by Behr (Ber., 1877, 10,351) but not conclueively proved. In the author'^ experiments awnitic add was ieolated from both healthy and diseased sugar cane, though it could not be obtdned in crystalline condition from the latter.It is present in the form of a salt and not in the free state in the oane juice. In addition to the usual qualitative tests it W&6 found that aconitic acid when treated with acetic anhydride gives a pink coloration, which changes rapidly to deep red and then to magenta.On heating the mixture a bluish-green liquid is obtained, which becomes brown and almost opaque. The magenta, liquid apparently consisted of two coloured subetances, EL red compound soluble in water, and a blue compound readily soluble in ether, but both were exoeedingly unstable and were rapidly decomposed by water, acids or alkdia Appaxently the colour reaction ia due to condensation of the carboxyl groups of the acid, with possibly elimination of water or addition of acetic anhydride.Applied as a test the reaction is capable of detecting 0.01 mgrm. of aconitic acid. None of the other acids in sugar-cane juice gives the reaction, but citric acid may be detected by melting it in a, test-tube, when traces of sconitic acid are produced, whioh then retact with the acletic anhydride.C. A. M. Purified Ether and the Variations in Commercial Samples. A. J. Jones. (Pham. J., 1919, 103, 71-73.)-The BP. prescribes tests €or the permissible limits of aldehyde, vinyl alcohol and methyl compounds in purified ether, and, as a rule, commercial samples amwer to these requirements. It is contended, however, that a, comparison with a standsrd of definite purity would be more satisfactory than determining the absence of a dass of compounds.AnaIyseEt are given of variou~ commercial samples of ether, in which methy1 compounds range from PO2 to 0*06 per cent., sp. gr. from 07182 to 097211, and ketones (as acetone) from 0.09 to 5-0 parts per 10,000. It is suggested that en apparent 0.05 per cent.limit of methy1 abohol would be reasonable for purified ether made from methylated spirit. A few samples of commercial ether gave practically a negative result in the nitro-prussida test. One sample which had been made from reotified spirit and kept for some time mntained formaldehyde. C.A M. Deteotion of Wheat, Rye, and Potato Starches fn the Presenoe of each other. Em Unna, (Zeitsch.Untmuch. Nahr. G~ertzlssm., 1918,36, 49.)-Ten grms. of the flour are mixed with 3 per cent. phenol solution and, after twenty-four hour#, a portion is transferred to a microscope slide and allowed to dry at the ordinary temperature. The slide is then immersed for ten minuteg in a mixture of mter.320 ABSTRACTS OF CHEMICAL PAPERS blue-oroein solution (water-blue, 1, orcein, 1, glacial acetic acid, 5, glycero1, 20, dcohol, 50, and water, 23 parts) and eosin solution (eosin, 1, 60 per cent. alcohol, 99 parts), washed, immersed for fifteen minutes in 1 per cent.saffrlbnin solutio& well washed, and immersed for tihirtg. minutes in 0.5 per cent. potassium bichromate solution. The preparation is finally washed with water, then with alcohol, treated with xylem, and mounted in Canada balsam.When thus prepared the potato starch is coloured dark red, the wheat starch pink, the rye starch yellow to brown, and the gluten blue. w. P. s. Estimation of Water in Masgarine. BB. MonhaupL (Chm. Z&t., 1919 43, 385-386.)-Loss by spirting when the water is expelled by heating the sample in a, basin over a flame may be prevented by the addition of a small quantity of sodium bioarbonate j about 0.03 grm.of the latter is sufficient for 10 grms. of margarine. The bicarbonate loses about 26 per cent. of its weight during the heating, a, loss which is praotically negligible under the circumstances. w. P. s. Modification of Nessler and Barths Method for the Estimation of Tannin in Wine. L. Meyep. (Mitt. Lebenm. Unterszcck. Hyg., 1918, 9, 131; through Chm. Zeit. Bep., 1919, 43, 125.)-One hundred C.C. of the wine are treated with alcohol to precipitate pectins, filtered, the filtrate evaporated to a, volume of 4 ao., transferred to a sedimentation tube, diluted with water to 5 G.c., and 5 C.C. of saturated sodium chloride solution, ferric chloride solution, and 1 C.C. of 40 per oent. eodium acetate solution are added. After twelve hours, the volume of the sediment is observed and multiplied by 0.33 to obtain the quantity of tannin. In the case of acid wines, the acidity must be reduced, by neutralisation, to less than 0.5 per cent. before the tannin is estimated. w. P. 23.