ANALYTICAL EDITION
AUGUST 15, 1939
No. 3006. Tests made on only the alkali-soluble portions of some of the extracts gave substantially the same results. I n this case it was possible to compare S o . 3006 directly with the toxicarol standard, the others again being compared with No. 3006. Some difficulty was encountered in matching the colors from the cube samples, and the use of the alkali-soluble fraction did not improve the color matching. The ferric chloride test indicates from 1.5 to 2.8 per cent of toxicarol and sumatrol in the cube samples, although recently Rowaan and Van Duuren ($3) reported that they had been unable to find toxicarol in Lonchocarpus (cube) roots. The color may be due to other phenolic compounds. For comparison the amount of alkali-soluble material was determined by a method previously used (15). This value ( J ) agrees with the results of the ferric chloride test more closely in the derris roots than in the cube and timbo roots, indicating that in the latter more of the alkali-soluble material is nonphenolic. Conclusion In evaluating derris and cube roots it is now possible-by making use of colorimetric procedures and a determination of rotenone by the usual method to obtain a t least approximate values for deguelin and toxicarol-by the Goodhue modification of the Gross and Smith color test to arrive a t an estimate of the insecticidal value (for houseflies), and by the Meyer color test to get a rough idea of the total materials of the rotenone type.
Literature Cited (1) Ambrose, A. M., and Haag, H . B., IND. ENQ.CHEM.,28, 81521 (1936). (2) Buckley, T. A., J . SOC.Chem. Ind., 55, 285-91T (1936).
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(3) Cahn, R. S., Phipers, R. F., and Boam, J. J., J . Chem. SOC. (London). 1938. 513-36. (4) Cahn, R. S : , Phipers, R. F., and Boam, J. J., J . SOC.Chem. Ind., 57, 200-9 (1938). (5) Danckwortt, P. W., Budde, H., and Baumgarten, G., Arch. Pharm.. 272, 561-9 (1934). (6) Dennis, W. J., U. S. Patent reissue 18,667 (Nov. 22, 1932; appl. Feb. 25, 1929). (7) Fischer, W., and Nitsche, G., Mitt. Biol. Reichsanst. Land. u. Forstw., 50, 57-78 (1935). (8) Geoffroy, E., Ann. Inst. Colon. Marseille, 2, 1-86 (1895). (9) Gimlette, J. D., “Malay Poisons and Charm Cures,” 2nd ed., p. 221, London, J. and A. Churchill (1923). (IO) Goodhue, L. D., J . Assoc. Oficial Agr. Chem., 19, 118-20 (1936). (11) Goudswaard, A., and Timmers, J. C., Pharm. Weebblad, 74, 630-4 (1937). (12) Gross, C. R., and Smith, C. M., J . Assoc. Oficial Agr. Chem., 17, 336-9 (1934). (13) Harper, S. H., Chemistry &Industry, 57, 1059 (1938). (14) Ishikawa. T.. Jamn Med. Lit.. 1 (Pt. 2). 7-8 (1916). (15) Jones, H . A., Campbell, F.L., and Sullivan; W. N., J. Econ. EntomoL., 28,285-92 (1935). (16) Jones, H. A., and Graham, J. J. T., J . Assoc. Oficial Agr. Chcm., 21, 148-51 (1938). (17) Jones, H. A., and Smith, C. M., IND.ENQ.CHEM.,Anal. Ed., 5, 75-6 (1933). (18) Jones, H. A,, and Sullivan, W. N., J . Econ. Entomol., 31, 400-5 (1938). (19) Meyer, T. M., Rec. trav. chim., 55, 954-8 (1936). (20) Pozzi-Escot, E.. Rev. cienc. facultad cienc. bid. fis. mat. univ. Major de Sun Marcos (Peru), 38, No. 417, 21-5 (1936). (21) Ibid., 38 (420), 47-51 (1937). (22) Rogers, H . D., and Calamari, J. A., ISD.EXG.CHEM.,Anal. Ed., 8, 135 (1936). (23) Rowaan, P. A,, and Van Duuren, ,4.J., Chem. Weebblad,35,7556 (1938). (24) Sillevoldt, H. E. T. van, Arch. Pharm., 237, 595-616 (1899). (25) Takei, S., Miyajima, S., and Ono, M., Ber., 66, 1826-33 (1933). (26) Tattersfield, F., and Martin, J. T., Ann. Applied B i d , 22, 578-605 (1935).
An Auxiliary Sliding Scale for Burets A. A. HIRSCH Sewerage and Water Board, New Orleans, La.
M
ASY routine titrations, which require only a relatively small volume of standard solution, may be expedited by taking readings from an attached sliding scale rather than using graduations provided on the buret. Details of the auxiliary scale are shown in the figure. The slide consists of a small brass strip t o which are soldered two brass springs that clip over the buret. Divisionmarks, similar to those on the buret, are made in ink on a piece of white paper glued to the brass strip. In use the zero mark of the slide is set initially to coincide with the
bottom of the meniscus and, after reaching the end point, the titer is read directly from the final reading on the auxiliary scale. By rotating the slide slightly toward the front, the left margin of the divisions will be aligned directly with the axis of the buret and permit better observation of the meniscus. The use of this device for small titers obviates constant refilling to zero level of buret to eliminate subtractions. Only one numerical reading, the final, need be taken, since the first is always zero. Chance of error in subtractions is thereby avoided. The device permits extension of usable length of buret beyond graduation limits provided by the manuf acturer. It allows direct conversion of titer into any system of expression without calculation, if the auxiliary slide is specially divided for the purpose. A buret dispensing a single standard solution may be equipped with a number of such sliding scales calibrated for each different application.
