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macromolecule would be inapplicable in this lower range; this confirms the conclusions of Badger and Blaker. SEYMOUR NEWMAN. Southern Regional Research Laboratory Agricultural Research Administration U. S. Department of Agriculture New Orleans, Louisiana February 2, 1950
A METHOD FOR DETERMISING THE PROPERTIES OF MICELLES We have found it possible to obtain thermodynamic and kinetic data about micelles formed by association colloids by “tagging” the micelles with a minute amount of a solubilized material such as a dye. In aqueous solutions of soap, for example, water-insoluble dyes are taken up by micelles alone (J. W. McBain: Frontiers in Colloid Chemistry, Interscience Publishers, Inc., New York (1950)) and the movement of the dyes, and therefore of the micelles, may be observed under the influence of various forces. Thus the self-diffusion coefficient of the micelle (or at least of the average solubilizing micelle), its electrophoretic mobility, sedimentation equilibrium, etc. may be determined. These lead by wellknown methods (Alexander and Johnson : Colloid Science, Oxford University Press (1949)) to an estimate of the molecular weight, charge, and approximate shape of the micelle. The method is generally applicable to solubilizing particles in both aqueous and nonaqueous solutions and may be used with any solventinsoluble tracer as well as with dyes. In preliminary experiments we have estimated the electrophoretic mobility and the diffusion constant of the micelle in 5 per cent potassium laurate containing 4 mole per cent potassium hydroxide on the soap, using Sudan IV, a water-insoluble dye, as a tracer. We have also observed the sedimentation in a centrifugal field of micelles of sodium lauryl sulfate containing Sudan IV. The electrophoretic movement of ascending and descending boundaries between the tagged and the dye-free solutions of the same concentration was observed in a standard Tiselius apparatus made available through the kindness of Dr. E. Jameson. Owing to the absence of density differences, a parabolic boundary is obtained. Diffusion was observed between two similar solutions in an unstirred sintered-glass diaphragm cell made available by Professor A. Adamson. Sedimentation was observed qualitatively in a McBain-Ford airdriven opaque centrifuge. The values obtained were D = 0.04 cm.*/day and u = 2.3 X crn.l/volt sec. The only comparable, although differently interpreted, measurement is D = 0.06 cm.Z/day obtained by Dean and Vinograd (J. Phys. Chem. 46, 1091 (1942)) for Yellow AB in Aerosol OT.
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On the basis of our values, it appears that the average solubilizing micelle in 5 per cent potassium laurate hFs effectively 12 negative charges, an equivalent spherical radius of about 25 A., and a molecular weight of at most 40,000, corresponding to 170 soap molecules. We are indebted to the Bristol Myers Company for support which made this work possible. HORST W. HOYER. Department of Chemistry KAROL J. MYSELS. University of Southern California Los hngeles 7, California March 22, 1950
B O O K S RECEIVED BR.AI-.AIS, 31. A On the Systems Formed by Points Regularly Distributed on a Plane or in Space. Translated by Alios J. SHALER. The Crystallographic Society of America Memoir S o . 1 . May be obtained from W. Parrish, Crystallographic Laboratory, Philips Laboratories, Inc., Irvington-on-Hudson, Xew York City. 1949.113 pp, Price: $3.40 to members, $3.90 t o nonmembers of the Society. DANIELS,FARHISGTON, ~IATHEW JOSEPH S , HOWARD, WILLIAMS,JOHN WARREN, BESDER, par^, MURPHY,GEORGEW . , A m ALBEHTY, ROBERTA . Experimental Physical Chemi s t r y . 4th edition. XZcGraw-Hill Book Company, Inc., 300 West 42nd St., Kew York 18. 1949. 568 pp. Price: $4.50. KARVE,D. D. An Elementary Teztbook of Organic Chemistry. Dastane Brothers’ Home Service, Ltd., 456 Raviwar Peth, Poona 2, India. 1949. 192 pp. Price: Rs. 2-12-0. KARVE, D . D., ASD ADVASI,G. D . Selected T o p i c s f r o m Organic Chemistry. Dastane Brothers’ Home Service, Ltd., 456 Raviwar Peth, Poona 2 , India. 1947. 418 pp. Price: Rs. io/--. KIRK, PAVLL. Quantitatice Cltramicroanalysis. John Wiley and Sons, Inc., 440 Fourth Ave., New York 16. 1950. 310 pp. Price: $5.00. NIVES, WILLIAM R., J R . T h e Fundamentals of Detergency. Reinhold Publishing Corporation, 330 West 42nd St., S e w York. 1950. 256 pp. Price: $5.50. PARTINGTON, J. R . .4n Adt,anced Treatise on Physical Chemistry. Vol. I . Fundamenta Principles, T h e Properties of Gases. Longmans, Green and Company, Inc., 55 Fifth Ave., S e w York. 1949. 943 pp. Price: S16.00. REIKER,~ I A H KDeformation US. and Flow. H . K. Lewis and Company, Ltd., London. 1949. 346 pp. Price: $6.50.
Third S y m p o s i u m o n Combustion and Flame and Explosion Phenomena. Published under the auspices of the Standing Committee on Combustion Symposia: Bernard Lewis, C h a i r m a n , Hoyt C. Hottel, Secretary, and A . J. S e r a d . The Williams &- Wilkins Company, Baltimore 2, hlaryland. 1949. 748 pp. Price: $13.50. Frontiers i n Chemistry. T-ol. V I I I . Frontiers in Colloid Chemistry. Edited by R. E. B U R R ASD OLIVER GRUMZIITT. Interscience Publishers, Inc., 215 Fourth Ave., Kew York 3 . 1950. 157 pp. (To April 4, 1950) ADAMS, DOUGLAS P . (Compiler and Editor). An I n d e x of S o m o g r a m s . Published jointly by The Technology Press of The Massachusetts Institute of Technology and John Wiley and Sons, Inc., Kew York. 1950. 174 pp. Price: $4.M).
