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OXIDATION OF METALS AND ALLOYS
0. Kuboschewski and B. E. Hopkins, Principal Scientific Officers, National Physical Laboratory. Academic Press, Inc., New York, 1953. xv 239 pp. 84 figs. IS tables. 16 X 25.5 cm. $6.
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THISbook serves as a n excellent reference to the subject of high-temperature oxidation and is a helpful guide to the extensive literature on this subject. The authors defined their field of hightemperature oxidation t o include processes occurring ahove 100°C., and in choosing metals t o discuss found that they had most of the periodic system over which to roam. As they state: "With the exception of gold, no pure metal (including platinum) and no alloy is stable in air a t room temperature. All metals tend to form oxides and many tend to form nitrides, although in many instances the rate of reaction is very slow a t low temperatures. . . . I n theory, all metallic compounds decompose a t high temperatures; in practice, however, most of these decomposition temperatures are above the boiling points of the parent metals or their campounds. This means that mast metals of the solid or liquid state are unstable in air a t any temperature." Here is a. book in whieh one can find tabulated the relative
phases of diffusion seemingly less important are included. Some parts of the discussion seem more appropriate to a n appendix, but in other respects the organization of material is good, and the reader is quickly oriented with respect to the phase of the subject in whieh he is interested. The book will prove to be avaluable reference for both chemists and metallurgists. HERBERT H. UHLIG MABB*CWJBETTB INBTITOT~ 01.T E C ~ N O L O O T C*laanroor, MAaaAcanseTTs
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ANIMAL BIOCHROMES AM) STRUCTURAL COLORS
Denis L. Fox, Professor of Marine Biochemish.y, Seripps Institution of Oceanography of the University of California. Cam379 pp. bridge University Press, Cambridge, 1953. xiii 3 plates. 3 7 figs. 11 tables. 16 X 25 cm. $11.
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EVERYONE, mientist and nonscientist alike, enjoys the aesthetic pleasures afforded by the brilliant colors of the m i m d world: the iridescence of birds' plumage, the rich and lively hues of many fishes and reptiles, the intricate patterns of pigmentation in the bodies and wings of insects. While the layman is ordinarily tion such as the Arrheniusreaction-rate constants for metals cam- content with the contemplation of these beauties, the scientist bining with air, oxygen, and nitrogen. There is detailed informa- has pursued his fascination in an attempt t o discern their meaning tion an oxidation ~.atesof all the common metals and alloys and and t o give an account of them as biologicaJ and chemical some information isineluded for the uncommon metals like cerium phenomena. Professor Fox has given a n excellent summary of the enormous amount of research that has been directed toward or thorium, or for elements like silicon, germanium, and arsenic. One learns that molybdenum can be heated to 200PC. for two the description and analysis of animal coloration, and he has hours without lasing metallic luster, but s t 3009C. the metal he- written withazest that betrays his own delight in his subject. Of the 14 chapters in the book, the first five are devoted to an comes steel blue in color. Tungsten, a n the other hand, stays bright for two hours a t a temperature of 30O0C. Only COOis introduction and to a consideration of the structural colors found on cobalt ahove 900°C., but CoaOl is found over a COO produced by Tyndall, diffraction, and interference phenomena. layer a t lower temperatures. These are among the many odds The remaining chapters deal with the organic pigments: the carotenoids, quinones, anthocyanins and flavanes, indigoid and and ends of interesting data. Most of the discussion deals with factual information; the re- melanin pigments, porphyrins and hilins, flavins, purines and maining portions deal with experimental methods for determining pterins, and miscellaneous pigments of unknown or inoompletely oxidntian rates and for examining oxidation products. The known structures. The book is written with a keen appreciation of the position treatment of oxidation mechanisms brings to the fore the outatanding contribution made by the electrochemical or Wagner this area of study occupies with respect t o the more rigorously theory of o~idation. According to this viewpoint, now confirmed defined disciplines, and gives due consideration to such diverse by a rcspectsble number of experiments, metals like copper do points of view as those of ecology and 8t~ctUTalorganic chemnot oxidize by simple chemical reaction, but by diffusion of Cu+ istry. The emphasis is chiefly biological and is largely upon and electrons outward through the oxide, or. what is the equiva- those pigments and structural factors that are responsible for lent, diffusion of lattice vac&oies inward, ultimately becoming visible coloration. Pigments such as the flavins, which produce filled by C u t a t the metal surface. Electrons move outward si- no gross coloration, and the purines, which are colorless hut are multaneously, ortheequivalent positive holes(electrondeficiencies) often responsible for iridescence and structural whiteness, are move inward. Discussion of theory tends to be brief and is not treated in less detail and with limited attention to their metabolic presented from the standpoint of the beginner but rather on the importance. level of the advanced student who knows or is not averse to lookAs any good book should, this one raises questions as well as answers them. The reader will be impressed by the vast amount ing up the literature for a fuller discussion. This volume is written not primarily for the theoretician nor for of descriptive information and the relative paucity of exact the engineer, but is rather a synthesis of the two viewpoints. knowledge concerning the chemical identity or biological role of Coverage of the literature is thorough, based on a total list of ref- many animal pigments. The use of such terms 8 s epiphasic, erences numbering 549. I n view of this thoroughness, it is sur- bypophasic, xantbophyll, etc., t o describe caratenoid pigments, prising not t o find mention of the effect of Curie temperature on the description of echinoid quinanes by means of their absorption oxidation rates described clearly by Temmann and Siehel28 years maxima, and the many uncertainties that exist with regard to the ago and confirmed 3 years ago for the chromium-iron alloys. structures of the melanins, are indicative of the great amount of Furthermore, in discussing diffusion, the authors omit mention of re-examination and further research that would be needed t o the Iangmuir-Dushman relation for diffusion constants, although identify the multitude of pigments now recognieed only as
