W. BRAGG (WILLIAM H. BRAGG). Introduction to the Analysis of Crystals. Translated under the editorship of Ya. I. Frenkel. Series “The Newest Trends of Scientific Thought,” books 23–24, State Publishing House, Moscow—Leningrad, 1930, 222 pp. Price in binding 2 rub. 55 kopecks.

Six lectures delivered by the elder Bragg for a broad audience have been turned into 6 chapters of a small book, interesting and written with Bragg’s characteristic popularizing talent. The chapter titles are as follows: ch. 1 — Reflection of X-rays by a crystal lattice; ch. 2 — Methods of analysis; ch. 3 — Simple inorganic crystals; ch. 4 — Space groups or crystal structures; ch. 5 — Some complex crystals; ch. 6 — Metals.

The first three chapters concern the methodology of investigation and the structure of the simplest crystals, i.e., that which also constitutes the content of the more detailed book by the Braggs, father and son, X-rays and Crystal Structure. In the booklet under review the exposition is more compressed, but much has been included both from the field of methodology (for example, complete rotation diagrams) and from the field of structures (the structure of $\alpha$- and $\beta$-quartz), which is absent from the Braggs’ main book. Chapter 5 is of interest (the structure of silicates, organic compounds), as far as the latter-

of the chapter “Metals,” it is too brief for one to expect to find in it anything more than an indication of the questions facing the investigator.

And this book, despite its unquestionable merits and the interest it arouses, nevertheless makes one recall with regret that we do not have in Russian a single book in which the reader could become thoroughly acquainted with the methods of applying structural X-ray analysis to physicochemical and technical problems. The translation is not entirely consistent in its terminology. The booklet is well produced.

C. K.