Book Reviews ATOMIC ABSORPTION SPECTROSCOPY, by James W. Robinson, Marcel Dekker, Inc., New York, N.Y. 1966. 204 pages, illustrated and indexed. Price $9.75. Atomic absorption spectroscopy is a relatively new analytical tool but its importance is growing steadily. De- spite the difficulties of interferences by extraneous elements, the rising popularity of this technique is due to its speed and relatively low cost. Atomic absorption spectroscopy is, in effect, the reverse of emission spec- troscopy. The major difficulty is the problem of generating the element (usually metallic) from its compounds before atomic absorption spectros- copy can be carried out. Thus, a large portion of this book is devoted to descriptions of atomizers, i.e., equipment which generates neutral atoms. This book is concerned primarily with practical problems. Accord- ingly, the theory of spectroscopy is deemphasized instead, much space is devoted to equipment and to methods for the determination of about 50 ele- ments. This includes most of the metallic elements which are present in cosmetics either deliberately or as im- 831 purities. It is likely that this tech- nique, for which relatively inexpen- sive commercial equipment is avail- able, will soon receive wider applica- tion in the cosmetic and other indus- tries. This book should prove to be a worthwhile introduction to these newer methods and a practical guide for the analyst.--M. M. RmCER-- Warner-Lambert Research Institute. AOINO, edited by William Montagna, Pergamon Press, Oxford, England. 1966. 237 pages, illustrated and indexed. Price $15. "Aging" is the report of the May, 1964, "Oregon Symposium" it con- tains contributions from some of the foremost authorities in their respec- tive fields. Thus, this reader looked forward eagerly to the task of review- ing this, the sixth volume in Mon- tagna's Advances of the Biology of Skin. Unfortunately, his anticipa- tion was not fulfilled by this book. Publication more than two years later of the papers delivered at a meeting is a delay which materially reduces interest. In the meantime, several of the papers, especially those presenting new findings, have ap-

832 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS peared in various scientific journals repetition now can be justified only by the attempt to publish the complete proceedings of the symposium. Aging of the skin and of its ap- pendages is an important social prob- lem for older members of a youth- oriented society. It is surprising, therefore, that this book includes only one chapter on attempts to improve or rejuvenate aging skin by clinical methods. On the other hand, about 15 of the 17 chapters of this book deal with comparisons between young and old skin. Unfortunately, the reader is not alerted to the fact that horizon- tal aging studies--and this book is concerned only with comparisons be- tween skin of different individuals of different ages--are not as definitive as longitudinal studies. The reader of a scientific book is en- titled to expect the author to delineate new problems, point out unusual findings, and if possible give some scientifically sound explanation. Thus, it is disturbing that one author neglected to mention that amino add analyses of derreal tissue suggest that the total collagen content of elastotic skin is closer to that of skin from pre- mature infants than that of normal (?) adults. This reviewer is not qualified to judge the histological and morpholog- ical observations of aging skin which account for several major chapters in the book. On the other hand, some of the gross observations of the gray- ing of hair appear to be not quite justified. One of the authors states that "graying appears first on the temples .... In a recent exmnina- tion of eight octogenarians, virtually no hypomelanotic hairs were found in the axillae, presternum and pubis." From personal observation, this re- viexver knows that graying in males frequently occurs first in the prester- hum area. In the same section it is noted that "before the hair becomes completely white, the pigmentation of the individual hairs that together with others look gray, may cover the entire range of color dilution.' This statement implies that fibers grad- ually change color until they finally turn completely white and is, there- fore, contrary to observed facts. Despite the above-voiced objec- tions to the book, this volume is im- portant reading for those of us who are interested in the aging of skin and related phenomena. The book pre- sents some significant new data, on one hand, and, at times, is an excel- lent and comprehensive review. The reader is, however, advised to analyze and examine observations and state- ments with considerable care before accepting all the conclusions made by the contributors.--M. M. RIEGER-- Warner-Lambert Research Institute. ENCYCLOPEDIA OF CHEMISTRY, 2nd Edition, edited by G. L. Clark and G. G. Hawley. Reinhold Publishing Corp., New York, N.Y. 1966. 1114 pages, illustrated and indexed. Price $25. The reviewing of an encyclopedia is not an easy task: Sometimes the value of an encyclopedia lies in the number of entries, and sometimes it is to be found in the colnpleteness of