BOOK REVIEWS timely, as it includes the metabolic fate of the steroids and the role of ascorbic acid in their metabolic transformation. In this volume, the author has achieved a. felicity of diction that is commendable. The references are numerous and the printing is clear, which makes reading the volume B pl~mure.
JOHN C. KRANTZ, JR. School o j Medicine University of Mwyland Baltimore 1 , Afmyland Block and GmH Polymers
William J. Burlant, Ford Motor Company, and Allan S. Hoffman, Massachusetts Institute of Technology, Cambridge. Reinhold Publishing Corp., 166 pp. Figs. New York, 1960. v and tables. 16 X 23.5 em. $7.95.
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This is a book about "molecular engineering" of polymers, the synthesis of macromolecules of desired chemical structure, and physical properties from simple and readily available compounds. I n order to synthesize such tailor-made high molecular organic compounds one must understand the mode of reaetion of the constituents from which they are formed, the condit,ions under which the desired reaction takes place, and the eonfigurntion of theend product. I t is obvious that x substantial knowl-
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Journal o f Chernicol Educofion
edge of organic and physical chemistry, especially in the field of high polymers, is required t o approach such a. formidable task. The new techniques involved are now so actively pursued in academic and industrial laboratories that students with only a modest background in polymer chemistry need a general introduction and guide for further research in this most interesting and ohallenging field of modern chemistry. This purpose is splendidly fulfilled by the present baok whieh strikes a. happy medium between a simplified approach to a difficult subject matter and a too abstract treatment such as one can find in morespeeializod treatises. The book starts very properly with an explanation of nomenclnture of polymer compounds and a very illuminating definition of graft and block polymers. The attached table of addition and condensation compounds giving the structural formulas of the monomers and the corresponding polymers is quite unique and constitutes a most welcome help in the further perusal of the text. The main part of the book deals with the reaction mochenisms of the formation of graft and hlock polymcrs such as chain transfer, the role of free radicals and unsaturated bonds in polymerieatian, chemical initiators, and ionizing radiation. The latter method of inducing polymerization reactions h a been given a very comprehensive treatment and is introduced with 8. short description of the nature of radiation and its chemicsl effects. While tho baok is as instructive and comprehensive as could be possibly
expected within a. limited space, the same cannot be said about the index which omits mentioning of Cobalt-60, G-vdue, retardants, etc. These and many other terms that are often used in the text do not appear in the index which naturally limits the use of the book for reference purposes.
FRANCIS JOSEPH WEISS Science and Technologv Division Libmry of Congress Washington, D. C.
The Abundance of the Elements
Lameme H. Alle~,Observatory of the University of Michigan, Ann Arbor. Monographs and Texts in Physics and Astronomy, Volume 7. Interscicnce Publishers, Inc., New York, 1961. 283 pp. Figs. and tables. 16 X xi 23.5cm. $10.
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This book is one of two dealing with the topic of elemental abundances that have been published this year. The other by V. V. Cherdyntsev, was reviewed earlier. See THIS JOURNAL,38, 640 (1961). I t is inevitable that the simultaneous appearance of two books in this specialized field would invite compsrisons. The book by Aller reviewed here is, without question, written from the point of view of the astronomer and the astrophysicist. The subjects of abundances in the earth's crust and in the (Continued on page A240)
