491
NEW BOOKS
Powder Photographs. The chapters under “Structure Determination” are :VI. Determination of Unit Cell Dimensions; VII. Determination of the Positions of the Atoms in the Unit Cell by the Methods of Trial and Error; VIII. Evidence on Crystal Structure from Physical Properties; IX. Some Examples of Crystal Structure Determination by Trial; X. Electron Density Maps and Vector Maps; and XI. Broadened X-ray Reflections and their Interpretation. The reviewer feels that the chapters on crystal shape, crystal structure determination by t,rial and error methods, and electron density maps and vector maps will, because of their lucidity, prove particularly valuable to beginners and possibly t o other workers in the field. The book seems to be remarkably free from errors. The use, on page 185, of the term “molecular weight” as synonymous with the absolute weight of a single molecule is confusing and unnecessary. Some minor errors are as follows: I n Fig. 129, page 214, the lower curve, labeled 200, should be labeled 002; line 7, page 232, should read ‘L bc diagonal”; Table V, line 7, page 240, should read “hkl when 1 odd”; and line 4, page 353, s h o u d read “Fig. 218 (right).” Theprinting and binding have been well done. Thus, from all angles, the book is one which the reviewer can heartily recommend. HAROLDP. KLUG.
Advances in Colloid Science. 1‘01. I I . Scientific Progress i n the Field of Rubber and Synthetic Elastomers. By H. MARKA N D G. S. WHITBY(Editors). 453 pp. New York: Interscience Publishers, Inc., 1946. Price : $7.00. This book is a collection of review articles by different authors on scientific progress in the field of rubber and synthetic elastomers. Following the introduction by G. S. Whitby, there are chapters on “Second Order Transition Effects in High Polymers” by R. F. Boyer and R. S. Spencer; “Crystallization Phenomena” by L. A. Wood; “The Study of Rubberlike Substances by X-ray Diffraction Methods” by C. W. Bunn; “The Thermodynamic Study of Rubber Solutions and Gels” by G. Gee; “Significance of Viscosity Measurements” by R. H. Ewart; “Kinetic Theory of Rubber Elasticity” by E . Guth, H. M. James, and H. Mark; “Vulcanization” by H. Farmer; “Rubber Photogels and Photovulcanizates” by H. P. Stevens; and “Reinforcing and Other Properties of Compounding Ingredients” by D . Parkinson. The wide range of subjects covered makes i t certain that this volume will contain sornething of interest and importance to everyone working in the field of high polymers. Two chapters especially, that of Gee on thermodynamic properties and that of Ewart on the significance of viscosity measurements, serve as excellent critical r6sum6s of fields in which much work has been done and still remains to be done. The chapter by Farmer is a very good summary and evaluation of what is known from the chemical point of view about the process of vulcanization. I n short, the articles in the book are uniformly excellent. Each is accompanied by a quite complete bibliography. The book can be recommended unreservedly to all those interested in the field of high polymers. E . J. MEEHAN. Physical Conslants of Hydrocarbons. Vol. I I I . Mononuclear Aromatic Hydrocarbons. By GUSTAVEGLOFF. A.C.S. Monograph No. 78. xiv 661 pp. K’ew York: Reinhold Publishing Corporation, 1916. Price : $15.00. This volume extends to the mononuclear aromatics the very useful collection of data on physical properties already published by Dr. Egloff and his coworkers for simpler hydrocarbons. The physical properties included are melting point, boiling point, density, refractive index, and, where available, values for the critical constants, optical rotation, sublimation temperatures, and temperature and pressure coefficients for the appropriate constants. There is little for us to do in reviewing this book other than to point out the obvious facts that the hydrocarbons covered here are extremely important ones and that the book will
+
