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TAYLOR G., B., A N D LEHNER, S.: Z . physik. Chem., Bodenstein Festband, p. 30 (1931). THACKER, C. M., FOLKIN, H. O., AND MILLER,E. L . : Ind. Eng. Chem. 33,584 (1941). J. S., AND BARKER, W. F . : J. Chem. SOC.127,2520 (1925). THOMAS, J. S., AND RAMSAY, A . G . : J. Chem. SOC.123, 3256 (1923). THOMAS, THOMSEN, J.: Thermochemistry, translated by K. A. Burke. Longmans, Green and Company, London (1905). TIMOSHEV, V. G . , A N D ABRAMOVA, A . v.: J. Chem. Ind. ( U . S . S . R . ) 17, NO. 12, 24 (1940). TOVBIN, M. V.:Univ. Btat Kiev, Bull. Sci. Rec. Chim. 3, 221 (1937). TRIMBLE, H. M., AND EBERT,P. F . : J. Am. Chem. SOC.66,958 (1933). TURKHAN E., Ya., AND YIJDINA, V. I.: J. Chem. Ind. (U.S.S.R.) 16, No. 12 (1938). VOSBUROH, W. C., A N D CRAIG,D. N . : J. Am. Chcm. SOC.61, 2009 (1929). H.: Proc. Leeds Phil. Lit. SOC.Sci. Sect. 1, 97 WHITLAW-GRAY, R . , AND WHITAKER, (1926). WILSON,R . E.: J. Ind. Eng. Chem. 13, 326 (1921); J. Am. Chem. SOC.43,721 (1921). WREWSKY,M. S.: J. Russ. Phys. Chem. SOC.69, 69 (1927); Z . physik. Chem. A144, 244 (1929). WREWSKY,M. S., AND XIKOLSKY, B . : J. Russ. Phys. Chem. SOC.69, 77 (1927). YOST,D. M.,AND RUSSELL,H., J r . Systematic Inorganic Chemistry. Prentice-Hall, Inc., NewYork (1944). ZEISBERG, F . C.: Trans. Am. Inst.. Chem. Eng. 14, 1 (1922).
COMMUNICATION TO THE EDITOR EQUILIBRIUM SPREADING COEFFICIENTS OF AMPHIPATHIC ORGANIC LIQUIDS ON WATER Heymann and Voffe (J. Phys. Chem. 49, 2 3 9 4 5 (1945)) have recently published their reasons for believing that the equilibrium spreading coefficient on water of amphipathjc organic compounds is always a small negative value, approximating - iWk,where Wk is the contribution of the polar groups t o the work of cohesion of the organic phase. The writer has recently (J. Phys. Chem. 48, 75 (1944)) taken exception t o their reasoning as disclosed in an earlier note (J. Phys. Chem. 47, 409-10 (1943)). From their subsequent complete publication (lac. cit.) it appears more definitely that they have omitted certain material factors in the molecular and mathematical developments of their theory. Their argument, on the basis of an analysis of molecular forces (J. Phys. Chem. 49, 239-45 (1945), part 11),seems to err, or a t least t o lack definiteness, in regard to the location of the cross section BB', the assumed plane of separation in considering work of adhesion. Their argument assumes that separation is made between an oriented layer in the organic phase and the unoriented organic phase. While it is true that separation of the liquid column at AA' does correspond to the work of cohesion of the oil phase, in that two new unit areas of oil phase-air interface are formed, it does not seem to be true that separation a t BB' corresponds to the work of adhesion (oil phase-water phase). The assumed plane of separation, BB', lies above the oriented layer in the oil phase and presumably
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beyond the range of influence of the water molecules in the water phase, whereas the interface between the phases lies wit.hin or below the oriented layer or layers. Therefore, separation a t BB’ does not eliminate the preexisting interface, whereas the work of adhesion postulates the formation of unit interfacial areas of oil phase-air and water phase-air, and the disappearance of unit area of oil phasewater phase interface. Thus, the mechanism of separation postulated by Heymann and Yoffe is not equivalent to a reversal of the process of bringing the two phases into contact, and therefore may not be assumed to result in a free-energy increase equal to WL . If, on the other hand, it should be assumed that the cross section of separation is at the interface, within the range of influence of the water molecules in the water phase, then it becomes difficult to see the justification for their assumption that the separation “involves a very much smaller number of polar groups than separation across AA’.” It is agreed that the free-energy changes attributable to orientation are minor fractions of the work of cohesion and of the work of adhesion (say 20 per cent). Yet the mathematical argument of Heymann and Yoffe (J. Phys. Chem. 49, 23945 (1945), equations 2a t o 5 ) is concerned with these minor fractions (Wk and Wk,) , with speculation concerning their probable relative values. Little is said concerning the relative values of the major fractions of the work of cohesion and the work of adhesion,-namely, the work of separation apart from and in addition to the work of orientation. Assuming the validity of equations 2a and 3, and assuming the correctness of the interpretation of the terms involved, equation 4 is mathematically a non sequitur. Equation 4 assumes that W,’ is less than Wd by an amount equal to $WL, and that the major fraction of the work of separation is in each case equal t o W z ,which is the desired result. Subsequent equations assume the validity of their equation 4, and do not require further discussion. H. L. CUPPLES. Bureau of Entomology and Plant Quarantine U. S. Department of Agriculture Washington, D. C. January 25, 1946
NEW BOOKS E. MUNKS2nd edition. By N . TROENSEGAARD, H . MILLFORD.16.5 x 23.7 cm.; 126 pp. London: Oxford University Press,
On the Structure of the Protein Molecule. GAARD, AND
1944. Price: Dan. cr. 14.00. This brief monograph contains a statement of the experiments carried out by the author during the past twenty-five years t o support his view that the protein molecule “must consist of a heterocyclic ring system.” He is convinced that the current hypotheses which consider polypeptide chains as the basis of the structure are wrong, and that protein chemists have been misled because they have placed their entire confidence upon the results of hydrolytic decomposition of *.heprotein molecule with strong acids.
