NEW BOOKS public by the Federal Government, al though most states maintain a bureau of mines, geological survey, or similar organization where minerals found by state residents are identified without charge. Besides giving approximate costs at commercial laboratories of various tests for different groups of minerals, the re port describes the techniques employed and gives directions for sampling mineral occurrences.
NEW BOOKS An Introduction to Electronic Absorp tion Spectroscopy in Organic Chem istry. A. Gillarn and E. S. Stern, vii + 283 pages. Edward Arnold, Ltd., London, 1954. $8.00. Reviewed by JOHN GOULD, National Bureau of
Standards, Washington, D. C. The authors present rules to correlate empirically absorption bands in the 200to 1000-ηαμ wave-length region and the
chemical constitution of organic com pounds. This is accomplished by describing the wave length and intensity of absorption bands associated with a number of simple chromophores. These observa tions are later extended to show the effect of isolated, conjugated, and cumulated chromophores on the spectra of compounds containing multiple chro mophores. This presentation culmi nates in the application of these princi ples to the proof of structure of a num ber of naturally occurring compounds. The graphical presentation of data is a minimum and used only to illustrate the general shape of the absorption bands that are observed in the various cases. Tabulated data are used ex tensively to show the consistency of the position of bands and the molecular extinction coefficient (molar absorp tivity) for a series of compounds that contain like chromophores. The vol ume contains a wealth of information, as is indicated by the observation that the separate compound index lists be tween 700 and 800 compound names.
The volume contains as one minor topic a discussion of the nomenclature of absorption spectroscopy and the interrelation of units to each other. A section on instruments stresses the photographic method. Quantitative analysis is discussed briefly in two chapters, and stress is placed on the determination of vitamin A and other biologically active substances. The text is well documented by litera ture references. There is a bibliog raphy in which references are classi fied according to content. Separate author, subject, and chemical compound indexes are provided. Colorimetric
Methods
of
Analysis.
Vol. IV. 3rd éd., Organic II. Foster D. and Cornelia Snell. 676 pages. D. Van Nostrand Co., Inc., 250 Fourth Ave., New York, Ν. Υ., 1954. $12.50. Reviewed by W. F. PHILLIPS Beech-Nut Packing Co.. Canajoharie, Ν. Υ. This book is a supplementary text devoted to organic compounds not covered in Volume III and completes
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