you have an essentially fine text in an unattractive format-why not pep it up? Donald S. Allen Eisenhower College Seneca Falls, New York 13148
Simplified Circuit Analysis: Dlgltal-Analog
Logic Richard D. Sacks, University of Michigan, and Harry B. Mark, Jr., University of Cincinnati. Marcel Dekker, Inc., New 166 pp. Figs. and taYork, 1972. viii bles. 22.7 x 14.7 em. $6.50.
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This hwk is presented by the authors as a supplement to the existing texts for an upperclass or graduate electronics course for chemistry and other physical science students. The hook is not intended to he a complete introduction to electronics. I t is a reprint of two chapters from Volume I of the series "Computers in Chemistry and Instrumentation" (Dekker, Inc.). The first chapter deals with analog computation. All analog operations are treated using the Laplace transform. Not since C. N. Reilley's article on operational amplifiers in this Journal (39, A855, A933 (1962)) has this reviewer seen analog computation so treated in articles or books written for chemists. It is important to recoenize that a detailed mathematical undentandrng is not neressar) to use the transform approach The super~orrtyof the methad is particularly rewarding when considering operational amplifiers since the computational capabilities develop very naturally without a sophisticated mathematical background. The authors present the power of the approach in a clear and utilitarian manner. The rudiments of the general method for analog programing of differential equations with some linear examples to demonstrate amplitude and time scaling are covered. The solution of simple algebraic equations is also treated. Throughout the first chapter the operational amplifier is treated as a black box. That is, aside from the input and feedback elements the hardware of the analog computer is not mentioned. The chapter covers analog computation not analog computers. The second chapter is devoted to digital theory. Digital counting, computation and logic are described. Included in this are Boolean algebra and minimization techniques, encoders, multiplexers and arithmetic networks. The emphasis is to show in detail how logic devices can manipulate numbers. The last 70 pages of the chapter are devoted t o t h e hardware implementation of these techniques. It is a Lucid presentation which then flows smoothly into the construction af gates and flip-flops. The emphasis is on the types of integrated circuitry commercially svailahle using the current terminology. It is worth noting that the authors use relatively little space in the hook to cover "hard core" hardware. This draws attention to the trend in electronics texts which A346
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is undelway. With the commercial availability of chips that contain the equivalent of 100 transistors it is questionable whether it is worthwhile to teach the operation of a transistor. In the future electronics texts for natural scientists may very well not even mention topics Like the hybrid parameters of transistors but deal only with the "external" operation of the sophisticated devices synthesized from them. Since it is hilled as a supplement the bwk is less vulnerable to criticism for omissions. Thus one need not expect to find explanations of circuit theory concents used in the bwk. The omission of open eulleetor gates is surprising. However as a teaching mstrument a serious umirsion is the lack of problems. Occasionally examples are given but there is no opportunity for a student to test his understanding. I believe this book is a valuable addition to the instructional literature in electronics. It is well written and can serve an important and useful funrtiun to supplement current tears for electronic courses m the natural sciences. I t will be particularly useful for the instructor who wants to cover recent developments in integrated circuit hardware as these apply to digital and analog operations.
Frederick 0.Tabbutt Evergreen State Coiiege Olympia, Washington 98505
An Introduction to Macromolecules Leo Mandelkern, Florida State University, Tallahassee. Springer-Verlag New York, Inc., 1972. Heidelberg Science Li161 pp. Figs. and brary, Val. 17. X tables. 15 X 22.7 em. $5.90.
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Most polymer scientists have developed a rather cynical attitude, no doubt also prevalent among other scientists, toward the plethora of books which are being published in their field. Whether because of innate human egotism or the economies of hook publishing, a new hwk on polymers seems to appear periodically, and with apparently increasing frequency. This ohvious duplication of effort raises serious doubts about the contribution which many of these hooks have to offer. "An Introduction to Macromolecules" happily raises no such douhts. In the first place, it is a small hwk (155 pp., paper hack), of which there are regrettably too few. I t presents, in five short chapters, a unified treatment of the field of macromolecules, suitable for reading and study by undergraduate science students. The chapter topics are, consecutively, Structural Features and Preparation, Chain Structure, Rubbers and Glasses, Crystalline Polymers and Fihers, Macromolecules of Biological Importance. In the second place, as the above sequence of topics might suggest, there is an orderly development of the fundamental physical properties of polymers based on the concept of the flexible chain molecule. The author starts by showing the relation
between valence bond character and conformations of the chain units, and how these considerations then govern the statistics of chain dimensions. A discussion of the restraints imposed by restrictions to hond rotation, temperature, and interchain forces naturally leads to a clear definition of rubbers, glasses and crystalline materials. This unified treatment of the physical properties from simple considerations of the long chain molecule (and ensuing networks) is difficult to find in mast hooks. The author also avoids the clutter usually introduced when the varied chemical structures of polymers are discussed. Finally, the effect of chain structure on physico-chemical behavior is dramatically illustrated by choosing (what else!) the biopolymers as examples. Biological macromolecules offer the most exciting examples of the control of chemical function by steric and conformational structures, while the nucleotides are of course the best possible source for demonstrating the ultimate in structure control during chain synthesis. On the negative side, one can find very little. Perhaps the most serious omission is the absence of any discussion of the dispersity of molecular weights, especially as it is related to the method of synthesis (Chap. 11). A minor, though irritating, point of criticism revolves around some incorrect nomenclature, e.g., "polyvinyl chloride" instead of poly(viny1 chloride). The author is not alone in this gaffe. The overriding quality of this book, however. is the combination of concise treatment and lucidity of exposition, which is so rare nowadays. Syntax is perhaps equally ss important as science, especially when we wish to communicate with the student. This hook is exceptionally good reading, and should be most successful in its goal, whether used as a course text or for individual study, of introducing the undergraduate science student to macromolecules a t an early stage. Maurice Morton The University ofAkron Akron. Ohio 44304
Cortisone Edword C. Kendall. Charles Scribner's 175 pp. Sons, New York, 1971, xii Photographs. 24 X 16 cm. $7.95.
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Although this book is not a textbook it certainly helongs in most college libraries. Far those of us who try to teach something of the human side of chemistry in our courses, it is a useful addition. In fourteen short chapters Dr. Kendall traces his career from boyhood in Connecticut, through school (PhD from Columbia in 1910) and several jabs, and finally to his receipt of the 1950 Nobel Prize in Medicine and Physiology (together with Philip Hench and Tadeus Reichstein).
