general methods are discussed, the necessary apparatus is well described and illustrated, and five different analytical determinations are given. An appendix of seventy pages contains logarithms, table of constants, and much other useful information, including a list of analytical reagents and analyzed samples. Sources of these materials are listed in this country as well as in England. The same is true of apparatus and materials frequently noted thraughout the book. A thoroughly adequate index completes the hook. This baok should find a place in any but the briefest elementary course, and serve for much subsequent advanced work. I t is written in a lucid style, easy far the student to follow, and it contains the illustrations and specific directions which help him to develop his analytical technic. The typography and arrangement is attractive, and the paper and binding are good. A teacher of an elementary course would certainly wish to supplement the work with many problems in chemical arithemtic, none of which is included in this volume. The advanced student would do well t o extend the study of the determination of single ions to a more general consideration of the separation of the components of mixtures, such as Lundell and Hoffman present in their OUTLINES OF METHODS OF CHEMICAL ANALYSIS. Reference to this and other supplementary material is found in the appendix, in the well-organized list of books and journals dealing with different aspects of quantitative analysis. Further elaboration of these points is beyond the scope of even such an inclusive book. The author has fulfilled his ambitious program well and has written a useful book, covering a wide field of application. FRANK T. GUCKER, JR.
IN~U~TR SOLVENTS. IAL Ibert Mellan. Reinhold Publishing Corporation, New York City, 1939. xi 480 pp. 267 figs. 126 tables. 15 X 23 cm. $11.00. This is a reference book written from the viewpoint of the technical man in the field of lacquers, plastics, and related products. The various solvents are discussed chiefly in relation to their dissolving action on cellulose and its derivatives, gums, natural resins, and other lacquer constituents. There is, howsuch as d m cleanine. ever. some discussion of other aDDlications . ". extraction, and the like. The r e d meat of the book is contained in Chapters 8 through Ifi which cover three hundred twenty pages in themselves. I n these chapters the various solvents are grouped according t o their chemical structure, e. g., hydrocarbons, alcohols, aldehydes, acids, ketones, and so forth. Each solvent is discussed individually, its uses and solvent characteriJtics are outlined, and its physical constants are given in detail. One very useful feature is that the various trade names for each camoound are gircn, thus furnishing the lacqurr chemist with information as ro the type of compound which is hcing advertised for this or that purpose in the trade journals. The book is filled with tables and graphs giving an enormous amount of information on specific heats, viscosities, vapor pressures, evaporation rates, specific gravities, and solubilities. This collection of data is alone worth several times the price of the hook t o anvone who uses solvents a m - a t deal. I n addition to thew data, there is an excellent chapter on plnsticircrs, and a chnprcr on rhe fundamrntels of graphical exprrscion and intcrpretation which explains thr mathen.atirs of the various types of curves used in expressing the properties of solvents and solvent mixtures. Aside from the practical information just mentioned, the 5rst seven chapters are devoted to a more or less theoretical discussion of the properties of solvents such as vapor pressure, evaporation rate, viscosity, intlammability, toxicity, and so forth, and this materid is of general interest t o chemists, even though they may not be users of great amount of solvents. One rather minor criticism that might be made is that while the author's theories as to solvent action are set forth in the first three chapters (especidly the first) the discussion is not very
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logical or clear. As a result, it requires r e d mental labor to get
a coherent picture of the material presented. If this defect were remedied, the hook could, to some extent, find use as a text in college work, and would be of value to students who planned to. pursue an industrial career. However, this deficiency does not affect its value as a reference volume. E D ~ W.DLOWE THBEDWAL L A B O R A T OINC. ~~S, carc*co. ILLlNOlS
THE DETECTION AND IDENTIFICATION OF WAR GASES. Minktry of Home Security, Air Raid Precautions Department. Chemical Publishing Co., New York City, 1940. iv 53 pp. 14 X 22 cm. $1.50. This little book is a service manual for the British G. I. 0. (Gas Identification Officer). This officeris not necessarily a chemist hut should have some technical training; he must be alert and have sound judgment. When a gas attack is made the G. I. 0. must hear about it, get there a t once, identify the gas, determine the extent of the danger zone, do what is to be done, and make a report. Details are given of the subjective methods of identifying gases, that is, by one's five senses aided by observations of the effects of the gas on people or on objects. I n most cases this will be the only evidence that can be secured, but the G. I. 0. carries a sampling and testing outfit packed in a box nine by four and one-half by four and one-half inches. If possible, he is t o secure samples which can be examined further or sent to the Laboratory. As information for the G. I. 0. and for any who may be concerned, the physical and chemical properties of the common war gaws are given and their physiological effects described. A general table gives for each gas, the name, odor, minimum perceptible concentration in milligrams per cubic m., nature of the effect. the intolerable concentration. and the "fatal omduct." This is the concentration in milligrams per cubic m. times the duration of exposure in minutes for fatal results. The book is written for a practical purpose and is well adapted
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TEE CYCLOTRON.W. B. Mann, Imperial College, London. Chemical Publishing Co., New York City. 1940. xi 92 pp. 31 figs. 10 X 16 cm. $1.50. This little book on the cyclotron and cyclotron technic would be instructive to any student of tlie biological and physical sciences who has mastered the principles of elementary physics. The evident importance of the cyclotron to all these sciences seems a sufficient justification for a book of thisscope. Assuming that the book is addressed to comparatively elementary students of physics and chemistry, who are not necessarily familiar with nuclear physics, and to more advanced biologists, there can be little quarrel with the text. It gives a clear and well-written account of the resonance principles which multiply the applied voltage a hundredfold, and of the focusing action which holds together a narrow beam of ions over a path of hundreds of meters. The more difficult problem of describing the apparatus in detail is satisfactorily handled, although these chapters might be somewhat condensed. From the point of view of the reader of little background, t o whom this baok should be most useful, there seems to be a great lack. Nowhere is it stated emphatically that the cyclotrm is simply a tool of nuclear physics, and that nuclear physics offers the possibility of as great advances in the knowledge of the nature of matter or chemistry and spectroscopy have already made. Without a definite statement of the end in view the book seems to he an exposition of art for art's sake. A final chapter, which might profitably be greatly expanded, does showuses of the products of nuclear reactions in chemistry and biology. HENRY W. NGWSON
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Tae U ~ r v ~ a s l rOFv Cnrcroo CHICAGO, I L U N O I S
