306 JOURNAL OF CHEMICAL EDUCATION

RADIOBIOLOGY SYMPOSIUM 1954 (PROCEEDINGS OF THE SYMPOSIUM HELD AT L I ~ G E , AUGUST-SEPTEMBER, 1954)

Z. M. Bacq, Professeur a'l'UniversitQ de Lie'ge, Membre Dorres- pondant d e 1'AoadQmie Royale de MQdicine d e Belgique, and Peter Alexander, Chester Beatty Research Institute, Institute of Cancer Research, Royal Cancer Hospital, London. Academic Press, Inc., New York, 1955. dx + 362 pp. Many figs. and tables. 16 X 25.5 cm. $9.80.

Trm volume contains the proceedings of the Radiobiology Symposium held in Liege in September, 1954. The meeting was attended hy scientist,s from 12 countries. There were 15 par- ticipants from the United States. The stated purpose of these symposia, which are apparently to be held annually, is to pro- mote exchange of information between physicists, chemists, biologists, and clinicians engaged in work involving the use of ionizing radiation. Most of the 50 papers collected in the present volume are by biologists and they describe studies of the response of intact animals, tissues, microorganisms, and isolated cells to ionizing radiation. A large number of these papers relate studies of protective suhstanoes and methods of influencing r e eove~y. There me three papers on the action of radiation on viruses and enzymes and about six papers on radiation effects in chemical systems. The majority of the papers consist of new experimental work and were written primarily for the specialist. However, anyone engaged in radiation research will probably find this volume of interest in that i t provides a fairly reprcsenta- t,ive cross section of the ourrent literature in radiobioloev.

A principal difference between this and the earlier edition is the inclusion of an excellent chapter on the Mathematical Basis of Resonance. This chapter represents no primrose path to the facile calculation of electron distribution in organic molecules, but the careful reader should obtain an umlemlanding of the methematical basis of both the resonance and the molecular orbital theories.

Walling's criterion for the copolymerization of styrene-methyl methacrylate mixtures by cationic and anionic reagents is incor- reetlv st,ated on naee 476 but oversiehts of this kind and tvoo- ~. . - graphical errors are practically abmnt. Tables and i~~ustraiibns are elear and well documented.

Although the discussions of molecular orbitals m e of r e d value, the treatment suffers somewhat from an inadequate description of atomic orbitals. Furthermore, the lack of three-dimensional representations (there are only s. handful in the entire book) occasionally causes unnecessary difficulty. Far example, in the discussions of carbon dioxide (page 112), the isocyanides (page 181), and the isocyanstes (page 180), the equivalence or non- equivalence of the structures described would be more readily understood through three-dimensional atomic orbital repre- sentations of the molecules. The reviewer would also have wel- comed a fuller treatment of the relative stability of organic cations and radicals.

However these are minor criticisms. The importance of the resonance viewpoint to organic chemists in general and to grad- uate students in particular is great indeed. Professor Wheland's able and thoughtful portrayal of the subject deserves their serious attention.

0 RESONANCE IN ORGANIC CHEMISTRY

George Willard Wheland, Professor of Chemistry. University of Chicago. John Wiley & Sons, Ino., New York, 1955. dii + 846 pp. Figs. and tables. 16 X 23.5 em. $15.

TEE 11 years which have elapsed since the appearance of "The Theory of Resonance" (reviewed by A. E. Remick, THIS J O ~ N A L + 22,207 (1945)) have seen no abatement in the interest and application of resonance to problems of organic chemistry. The new edition, of slightly modified title and over two and one- half times the length of the original, again takes a careful look a t organic chemistry as approached and interpreted from the resonance viewpoint. The farm and outline is similar to the earlier version, but much new material has been added and old materid has been brought up to date. Of equal importance, the critical care in expression in the first edition has, if anything, been replaced by even greater care in this new edition. The dia- cussion of the length of the carhon-chlorine bond in ohloroben- eene and that of the centre1 carbon-carbon bond in bibenzyl are two out of many instances in which attention is focused on sig- nificant but often overlooked considerations.

Chapters I-V and VII-The Theory of Resonance, The Nature of ~ n i c n c r , 1lw0,~:mvc t.:ncrp?., SrrrL. liffcrta of Iksonsnre, lkeonnnvr m d i)il.olr hlomrnts, n~rd Rwm~ncr . and Clwnmir:$l I.:auilil,rit~m-ll:l\.e undrreonr little e l ~ a r w from the fimt d ~ t i o t i wiih a few important exceptions such as the inclusion of a d e

- -

scription of the molecular orbital treatment of valence and recent methods for the calculation of heats of combustion. Substantial additions have been made to the chapters dealing with Resonance and Molecular Speotra and with Resonance and Chemical Re- action. The discussion of the speetrs. of specific classes of or- ganic compounds is of particular value as are the discussions of orientation of substituents in aromatic systems, copolymeriza- tion, and molecular rearrangements. The appendix of Inter- atomic Distances in Orwnic Molecules. which has increased nine-

* HAWLEY'S TECHNICAL SPELLER

Gessner G. Hawley, Executive Editor, Reinhold Bock Division, and Alice W. Hawley, Consulting Editor. Reinhold Publishing Carp., New York, 1955. 146 pp. 13.5 X 19.5 cm. $2.95.

OVER 8000 words, from a b a m to zymurgy, are alphabeti- cally arranged in very clear, eesily-read columns in this almos6 pockebsized volume. Except for two very short pages on chemi- cal notation, and three pages listing preferred prepositions to use with such words as correlate . . . (with), the book is devoted entirely to the correct spelling and permissible hyphenation of common technical words.

W. P. K.

PHYSIOCHEMICAL CALCULATIONS

E. A. Gugenhe im, Professor of Chemistry, and J. E. Pme, Lecturer in Chemistrv. both of Universitv of Readina. Holland. ~~ . . -. lnrerscience Publishers Inc., New York. 1955. mi T 491 pp. 77 figs. 200 tables. 15.5 X 23.3 cm. $7.

THIB interesting book illustrates the methods of c a v i n g out physical chemist,ry cdculations fromdata. published in thelitera- ture. One hundred and seventy-one problems are worked in different hranches of physical chemistry:

Each problem gives data taken from a published article and the reference to the article. The method of cslculation to be used is outlined, the use of the data is shown, and the significance of the results is usually discussed briefly. The problems are well ae- lected, and several errors in printing are corrected by n flyer in the front of the book.

Teachers and students should learn a great deal from a study of the hook.

~~ ~ ~ ~~ ~~

fold over the original one, strives for completeness up to 1954. Among other purposes, i t serves as a highly useful supplement to N O ~ T ~ E A ~ T E ~ N UNIVBRLITP

t,he chapter an steric effects. BOBTON. MABBACRDSETTB

ARTHUR A. VERNON