646 OPTICAL PROPERTIES (determined by W. C. AIcCrone). Refractive Indexes (5893 A,; 25" C.). a = 1.432 * 0.002. = 1.492 += 0.002. y = 1,553 * 0.002. Optic Axial Angles (5893 A , ; 25' C.). 2T' = 87". Dispersion. r > 6. Optic Axial Plane. 010. Sign of Double Refraction. Positive. hcute Bisectrix. y A c = 13" in acute 0. Ektinction. a A a = 24" in obtuse 13.
Molecular Refraction ( R ) (5893 25" C.). = 1.492. R(ca1cd.) = 36.0 (if RZ, = 4.8). R(obsd.) = 36.0. FUSION DATA(determined by W. C. McCrone). Zinc acetate dihydrate when heated melts just below 100" C and dissolves partially in its o m water of hydration. This water is soon lost on continued heating and the mass resolidifies as anhydrous zinc acetate. The anhydrous salt melts a t about 240' C. and on cooling solidifies spontaneously to give spherulites. Most of the crystals show low birefringence with an optic axis interference figure, 2V about SO", negative, little or no dispersion.
Manual of Clinical Laboratory Methods. Opal E . Hepler. 4th ed. xv 387 pages. Charles C Thomas, 327 East Lawrence St., Springfield, Ill., 1949. Price, $8.50.
Radioactive Measurements with Nuclear Emulsions. Herman Yagoda. is 356 pages. John Wiley & Sons, Inc., 440 Fourth Ave., A'ew York 16, N. Y., 1949. Price, $5.
This volume represents an expansion and enlargement of several earlier editions issued in planograph form. Its general availability will be more than welcome to many hospitals and clinical laboratories in which a rigid and accurate routine is of greater importance than background and fundamental understanding of the basis of the procedures used or of their interpretation. It covers the entire field of clinical laboratory methods including chemical, bacteriological, mycological, immunologicai. and other technique., in the typical style of an industrial rontrol manual. .\I1 instructions are outlined in A, B, C and 1, 2, 3 order, in a clear, terse, and completely dogmatic style. 1-nnecessary words have been ruthlessly eliminated, except for certain duplications of procedures applicable to more than one type of sample-a common practice in industrial manuals to avoid loss of time in referring back. The subjects covered, in order: are urinalysis. hematology, gastric and duodenal contents, liver function tests, feces, sputum, cerebrospinal fluid, body fluids, pregnancy tests, bacteriology, mycology, serology, blood groups, clinical chemistry, allergy extracts, tissue sectioning, basal metabolism, electrocardiography, and solutions. Each working procedure is given in order of operations, and the interpretation is given just as concisely and usually without detail or reasom. Methods are ordinarily identified by the names of their authors, and no references are included. For most constituents or operations one method only is given for any single examination or analysis. The routine clinical laboratory technician will find this volume as essential as his right hand, provided he or she does not disagree with the choice of procedures. The necessity of making choices or decisions is eliminated, and will result in great economy of time in routine operations. The academic scientist, research worker, or even the physician will find it useful chiefly as a broad source of operational detail for unfamiliar procedures. Certainly a large number of the analysis and examination procedures will be considered inadequate or unsatisfactory by the competent scientist. The best existing techniques are not always chosen and often far too little attention is given to interferences and analytical uncertainties. 'rhis is in complete accord with the expected use of the volume by strictly routine workers, not by research or investigative personnel. The typography, printing, and binding appear to be excellent. 1,lany simplified drawings are given as well as a considerable number of good black and white and color plates of cytological and histological specimens. For a book of this kind a further saving of time by some form of marginal indexing n-ould appear desirable. PAVLL. KIRK
This book is unique in that it brings together in one comprehensive treatment a thorough description of the theory and use of the photographic emulsion as an analytical tool in the study of problems involving radioactive emanations, together with the description of detailed techniques for the use of this tool in problems of chemistry, biology, crystallography, mineralogy, and metallurgy. Yagoda brings out clearly the importance and possibilities of the autoradiographic method wherein the photographic emulsion has given the possibility of detection and location of submicroscopic groupings of radioactive atoms with a sensitivity several orders of magnitude beyond that of microchemical techniques. The historical development of the subject of autoradiography with complete bibliographical references is especially good. It is made clear that with the newly available artificial radioactive isotopes, the improved emulsions now available, and the new techniques of sample preparation, the methods of autoradiography 7n-ill become increasingly important. To the scientific worker contemplating experiments in the field of radiotracer work with the photographic emulsion, this book is to be especially recommended. It describes the photographic emulsion, its advantages and limitations, gives numerous illustrations of sample preparation and handling for a variety of fields of work, describes methods of exposing and processing the emulsion, and gives detailed information on techniques of microscopy to be used and on the interpretation of the resulting autoradiograms. The last third of the book contains a good description of the uses and applications of the photographic emulsion in nuclear physics wherein problems in the fields of nuclear reactions, fission processes, cosmic radiation, and meson theory are treated.
Spectroscopy and Combustion Theory. A . G. Gaydon. 2nd 242 pages. Chapman and Hall, Ltd., ed. revised. xii 37 Essex St., London, England, 1948. Price, 25s.
It may be safely assumed that the experienced investigator in the combustion field is fully acquainted with the first edition of Gaydon's excellent book, "Spectroscopy and Combustion Theory." To the chemist just entering the field of flames and explosions, the broad background offered by this book makes it an essential to his education. The author's proved ability to present a clear picture of the quantitative as well aa qualitative aspects of the problem further recommends the work to any scien-
V O L U M E 21, NO. 5, M A Y 1949 tist interested in the mechanisms of light emission from reaction systems. Much of the new material presented in the second edition reflects Gaydon’s recent acceptance of the importance of atomic oxygen in combustion. His application of nitric oxide as a reagent for oxygen atoms in flames forms the core of the one nenchapter. The theory of dissociation continua is dealt with briefly and the less familiar subject of unquantized emission due to association reactions in much more detail. Gaydon includes in the new edition several sections of practical value to the experimentalist. The methods of study of emission spectra are discussed in more detail but nothing has been added to the equally important part on absorption spectra. The measurement of flame temperatures is given more complete treatment than in the original edition, including a useful compilation of calculated compositions and temperatures of some flame gases. The student of thermodynamics will find the chapter on dissociation energies of value, particularly the section on the heat of sublimation of carbon. Of practical interest is the amplified swtion on the mechanism of carbon formation in flames. Though the emission spectra of hydrocarbon flames are discussed in some detail, the combustion engineer will he disappointed by the extreme brevity of the sections dealing with gaseous explosions. None of the important advances in this field since 1940 are included. Because approximately 957, of the text of the original is repeated verbatim in the second edition, and thc major portion of t,he new additions has been adequately covered by Gaydon’s recent publications, this reviewer is inclined to question the neccssity of a new edition a t this time. However, he has no intention to discount the unusual skill of the author in presenting a comples subject in a concise and lucid manner.
Practical Analysis. Graphical and Numerical Methods. F r . A . Tt’illers. Translated by R. T . Beyer. x 422 pages. Dover Publications, Inc., 1790 Broadway, S e w York, X . Y., 1948. Price, $6.
Perhaps a more specific title for this book would be “Practical Mathematical Analysis and Computation.’’ The first of the six chapters discusses numerical calculation and its aids, such as the slide rule, calculating machines, charts, and nomograms. -411 chemists who are concerned with rapid or routine calculation and presentation of experimental data would probably benefit by reading this chapter. Chapters 2, 3, 4, and 6 deal with interpolation, approximate integration and differentiation of functions, theory of equations, and approximate integration of ordinary differential equations. Most of these are not of interest to the chemist, except for a few specific applications. The fifth chapter, on curve-fitting and empirical functions, is of some general interest. The book is mainly a translation of Killers’ German work, published originally i n 1928. Two parts, dealing with the slide rule and calculating machine; are w i t t e n to accommodate instruments of .American design. I t n-ould have been appropriate to revise and expand the reference lists to include more available and recent works in English. Use of generalized procedures or theorems is illustrated by many n-ell-worked, specific examples. These esamples are really outstanding, and they help the lay mathematician greatly in application and understanding. The subject material is rigorously treated. For an understanding of the xhole book, a good mathematical grounding through differential equations is necessary, though there are parts that require less preparation. While the text and style are clear and not undesirably concise, the book is designed for study and reference rather than for easy reading. The publishers state that this
647 work is universally recognized as the most complete in the field. and that there is no other single book in which the various mrthods are so carefully evaluated and compared. The rpvimer 17 inclined to agree with this statenicnt XALTLR J. J3r ~ L I I L L
Qualitative and Volumetric Analysis. J . ( I . Gzblin. 1st ed. xiv 175 pages. Longmans, Green and Co., 55 Fifth .ivc., S e w \?ark, K, T., 1948. Price, $1.60.
The author is a member of the Society of Public Analysts anti Other Analytical Chemists and senior chemistry master a t the Royal Grammar School in Worcester. The object of the book is “to provide a complete course in qualitative and volumetric analysis up to university scholarship standard. ” The small volume, which might be carried in a large pocket, is a laboratoiy guide for beginners in qualitative analysis and in titrimetry. The tTvo subjects are separately treated. The first 63 pages give what might be appropriately rallcd .‘tables for the identification of cations and anions.” Then follows a section of 20 pages on “Organic Reagents for l k t a l s and Acid Radicals.” The presentation of the classical scheme of analysis is in the European tradition. There is no statement on the size of sample to be taken, and the decision on quantity of reagents and their concentration is left to the judgment of the students. This provides the students with an excellent opportunity for learning, by trial and error, the elementary facts of inorganic chemistry, and much may be said in favor of this approach. The second half of the booklet, pages 85 to 170, gives brief laboratory directions for a course in titrimetry with the usc of color indicators. The selection of the sixty experiments is irigenious in the sense that it should stimulate the imagination of the students concerning the great variety of problems that can be solved by simple titrations. The directions are rather sketchy, however, and in some experiments the results must lack precision and accuracy. Still, a good teacher could base on this laboratory text an excellent survey course for students of medicine or chemical engineering. 11..A. BESEDETTI-PIf’ftLER
Scientific and Industrial Glass Blowing and Laboratory Tech388 pagcs. niques. W . E . B a r r and T’ictor J . Anhorn. viii Instruments Publishing Co., Pittsburgh, Pa., 1949. Price, $6.
For many years there has becn a great demand for a conip c3te manual on the art of constructing experimental glass apparaturi, including the many new developments in this field, so highly necesary in modern laboratories. This book explains for the scientist-glassblower, as well as for the more skilled glass tcchnician, a aide variety of techniques heretofore known only to experienced and highly skilled glassblowers. Besides the very interesting descriptions of apparatus building, and the liberal use of helpful diagrams and illustrations, there is a vast amount of technical data which have not previously bccn collected in one convenient manual. The reader will find this book completely up to date, as many highly modern commercial laboratories have been consulted in it,s preparation. The authors have well fulfilled their objectives as stated in the preface: knowledge of basic glass characteristics and fundamental techniques; advanced tcchniques, of which the section dealing with high vacuum tcchniques is especially commended; and description of advanced equipment for special applications in modern laboratories. This book will fill a need long felt by those researchers who are intcrestcd in building their own experimental glass apparatus. C. c. VAN IIEsl’EN