diffraction of X-rays by crystals, (2) some experimental methods, and (3) some applications to problems of importance in metallurgical research. In the hands of a competent scientist, X-ray diffraction is an exceedingly powerful and well developed means of studying the crystalline state. It is not a partieularly easy subject to learn, and in my opinion i t is a mistake to gloss over the fundamental conceptual difficulties as much as this book does. My advice t,o beginners is, "Study the fundamentals and get these right a t the start; if, for example, you find that the use of the reciprocal lattice is quite beyond your comprehension, give up!' Since this is mv educational point of view, it is inevitahle that I would dislike s. book which gives so little emphasis to symmetry when discussing the geometry of crystzls, does not discuss the Lme equations, and rekgates the reciprocal lattice to an appendix. T h e section on experimental methods deals a i t h Laue photographs, pander photographs, and diflractomcter measurements in ronsiderable deswiotive detail By far the best part of the book is the last three-fifths, which deals with applicat,ions. Of the ten chapters therein, the best are those dealing more specifically with metalhirgieal applications such as crystal orientations, pole figures, stress measurements. The chapter on st,rueture determination is too elemmtary to he of
much value in tackling any actual prohlem, and, to a lesser extent, the same is true of the chapters an phase diagram determination and ordcr-disorder transformation. This is essentially a descriptive book with the minimum of mathematics and exactitude. As such it is well and conscientiously written and can he reoommended to those who like their scientific books that way. I n fairness to t,he author, i t must be mentioned t,hst the reviemer is an X-ray cr.vstallogr~pherand not an X-ray metallurgist. G. A. JEFFREY U s r r ~ n a l r rO F P,TTBD"RCH Plrrseuxox. PENNBTLVAX~A
STERIC EFFECTS IN ORGANIC CHEMISTRY Edited by fessor of University. New York, figs. and $12.50.
Melvin S. Newman, Pro. Chemistry, The Ohio State John Wiley & Sons, Inc., 1956. vii 710 pp. Many tables. 15.5 X 23.5 cm.
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ORGANIC chemist8 everywhere will hemld this new book as one of the outstanding publishing contrihutians t o the srienee. From the lucid exposition of "Conformational analysis" in Chapter 1. by William G. Dauben and Kenneth S. Pitner, through thc critical analysis of the "Separation of polar, sterie and wsonnnre (Continmi on page A18Z)
JOURNAL OF CHEMICAL EDUCATION
hook is a must. For, theoretically, it certainly points the way to furthcr understanding in an important, area, and, expe~.imentally,it offers a guide t,o ot,ilisntion, dodong ncgleeted in certain qnsrters, of steric effcets in the control of orgmie reactions. The editor is to be further complimented for bringing to the ioregound sovcrel of the young giant8 who hevo contributed significantly to the dynamic g ~ o w t hof theoretical organic chemistry during the past decade. The reader will recognize their names a8 iuthors of the chapters already cited and among the authors ai the remaining rhapters: Ernest, L. Eliel, Chapter 2, "Substitution a t sat,urztrd carbon atoms"; Gcorgc S. Hammond and ill. Frsdcriek Hswt,harrrc, Chaptor 3, "Steric effects in aromat,ic substitution"; Melvin S. Ncwmau, Chapter 4, "Ad
