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BOOK REVIEWS
attention, but of particular interest are the contributions on the chemistry, physiology and toxicity of flavourings. The effects of these constituents on salivary and adrenocortical activity and on olfactory function are described and Ch.-A. Vodoz reviews the problems of the toxicity assessment of the numerous natural and synthetic flavourings now in use. The activities of the US Flavor and Extract Manufacturers' Association are referred to and the history of the banning of coumarin and safrole in the USA is outlined. The justification for treating flavourings as a very special class of food additives from the toxicological viewpoint and, at the same time, the need for establishing answers to the outstanding questions in this field receive particular attention.
The Biochemistry of Foreign Compounds. International Series of Monographs in Pure and Applied Biology, Biochemistry Division. Vol. 5. By D. V. Parke. Pergamon Press, Oxford, 1968, pp. ix -t- 269.75s. The author of this book has succeeded admirably in illustrating the various metabolic transformations of foreign compounds. The text, which provides copious examples of these transformations, is divided into two sections, the first dealing with biochemical mechanisms and the second with groups of compounds having similar applications, e.g. pesticides, drug and food additives. This classification increases the value of the book as a preliminary source of information leading on to major references, which are mainly in the form of published reviews. The book will be acquired by workers in many disciplines in both industrial and teaching establishments. Some criticisms are inevitable, but these do not detract from the overall value. The book is intended (by the author) for students of biological subjects, but it assumes a greater knowledge of chemistry than biology. For instance the concept of the entero-hepatic cycle is explained in some detail, whereas it is assumed that the reader is familiar with epoxidation and dealkylation. The title is somewhat misleading in that the text does not deal essentially with the biochemical effects of foreign compounds, but only with their metabolism. Since toxicology is gaining recognition in the modern world, there may be a temptation for its teachers to insist on the mental digestion and retention by students of the details of the metabolism of numerous compounds. This book could well become the 'compulsory catalogue' for such teaching, a fate which neither the student nor the book deserves.
Fundamentals of Autoradiography. By J. BeneL English translation edited by V. W. Rampton. Iliffe Books Ltd., London--SNTL, Prague, 1966. pp. 65. 8s. 6d. Autoradiography, a technique in which the pattern of radioactivity contained in or on an object is made visible by its effect on photographic emulsion, is widely used in fields ranging from medicine to heavy engineering. Quantities of radioactive isotope so minute that they are undetectable by conventional means can be demonstrated in this way and measurements can be made of relative concentrations, for example in different parts of a tissue or cell or in a single grain of a metal alloy. In this short text the author discusses the principles behind the choice of radioactive tracer, the types of photographic material used, exposure and development techniques and the quantitative aspects of the method. He achieves his object of presenting readers of varied scientific background with sufficient knowledge of the possibilities and problems of autoradiography to allow them to decide whether the method is of value in their field and, if so, which isotope and photographic materials to use.