JULY 15, 1936
ANALYTICAL EDITION
literature (9). Using standard of concentration close to that of unknown would aid in obtaining higher accuracy. This method is far more rapid than others and where interfering substances are present in the gravimetric method, it is better than none. It is a t present being studied for better development. As the hydrolysis of salicin proceeds, the following changes take place: Shortly after the solution reaches a temperature of 80” C., a white turbidity is noticeable. This turbidity changes slowly in an hour or so to a pink precipitate which grows deeper in color as the time of heating and evaporation proceeds. For quantitative conversion, it is essential to evaporate very slowly and a t a temperature never higher than 80” c. The length of time necessary for accurate results indicates that the formation of saliretin proceeds with a definite velocity. The rate of this reaction has never been studied. The concentration of hydrochloric acid is of great importance for, when it falls below a certain minimum, the reaction does not yield quantitative results within a reasonable time. This work was Derformed in the Chemical Laboratorv of the Bureau of Food and Drugs, Department of Health, City of New York.
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Literature Cited Anwers, K., and Michaelis, F., Ber., 47,1275 (1914). Beilstein, F.,and Seelheim, F., Ann., 117,83 (1861). Beilstein, 3rd ed., Vol. 111, p. 608 (1897); Vol. 11, p. 1109 (1896); Vol. 11,supplement, p. 680 (1903). Cumming, W. M., Hopper, I. V., and Wheeler, T. S., “Systematic Organic Chemistry,” 2nd ed., p. 441, New York, D. Van Nostrand Co., 1931. Dott, H. B., Pharm. J.,119, 691 (1927). Gerhardt, von, Ann. Chim., [317,215 (1843). Hudson, C. S., and Paine, H. S., J. Am. Chem. Soc., 31, 1242 (1909). Jackson, K. E., and Dehn, W. M., IXD.ENO.CHEM.,Anal. Ed., 6,382 (1934). Kerstan, G., Planta (Abt. E., 2. wiss. Biol.), 21,657 (1934). Kraut, K., Ann., 156,123 (1870). Meyer, K. H.,Irschick, A., and Schlosser, H., Ber., 47, 1741 (1914). Meyer, K. H., and Lenhardt, S., Ann., 398,66 (1913). Moelwyn-Hughes, E. A., Trans. Faraday SOC.,24,309 (1928). Piria, R.,Ann., 56,35 (1845). Voswinkel, A., Chem. Zentr., (1900) I, 771. Ware, A. H.,Chemist and Druggist, 120,74 (1934). Wischo, P.M. F., Pharm. Post, 28.42 (1895). RECEIVED February 4, 1936.
Battery-Type Stand Assembly for Distilling Equipment *
ROY L. MOBLEY, P. 0. Box 1021, Baton Rouge, La.
T
HE efficiency of distillation has in many ways been lowered by the equipment available. I n the older types of apparatus vapors and liquids were brought in contact with metals, and with cork and rubber joints, stoppers often leaked, and in some instances the units making up the apparatus were inefficient. The advent of all-glass interchangeable-joint apparatus and improved condensers has brought about much greater efficiency and more accurate results. However, the complete change of type and general form of equipment has made older accessories obsolete, and it is extremely time- and accessory-consuming to set up two or more of the newer types a t a time. I n an attempt to overcome these handicaps, the author made the necessary calculations and arrangements, diagrammatic sketches, etc., and developed a working model of a battery-type stand assembly which has proved very satis-
factory during the past 3 years. The photographs show front and diagonal end views of the assembly as built for 500-cc. distilling flasks and indicate arrangement of the parts. The apparatus was built and used in the laboratory of William L. Owen, Baton Rouge, La. RBCEIVED May 14, 1936.
CORRECTION. In the article on ILDeterminationof Nitric Oxide in Coke-Oven Gas” [IND. ENG.CHEM.,Anal. Ed., 8, 164 (1936)] an error was made in Figure 2. The glass balls should be of 6or 6-mm. diameter, as the 8-mm. balls specified would be entirely too large for this apparatus. J. A. SHAW
