been alter&, a few new exercises have been substituted and the references brought up t o date, hut so far as "majors in chemistry" and "high-school graduates of average ability" are concerned the changes would appear to be insignificant. I n chapters 19 and 20 the discussion of "Modern Ionic Theories" and "Applications of Ionic Theory" is somewhat less complete than that given in chapters 17, 18, and 19 of the earlier text, hut would still he considered a rather heavy assignment by many teachers. After thisshort divergence the two volumescontinue to he closelysimilar up to the section an organic chemistry, which has been entirely rewritten. The next major change is the removal of chapter 34 on coordination compounds in a condensed version t o chapter 43 ("Iron, Cobalt, and Nickel"). I n the later chapters the changes consist of a condensation in the discussion of electrochemistry and less emphasis on metallurgy. The descriptive chemistry. except for that of the transitional elements, remains essentially unchanged. Thechapter on alloys bas been omitted. The earlier text had no appendix and in the new text a few tables which had previously been printed in the body of the volume have been put a t the end. These are: the tables on weights and measures, color scale of temperature, solubilities of inorganic substances, and the long table of stable isotopes. Thus the present volume appears to the reviewer to he more accurately described as a revised edition rather than a new and simplified textbook. These remarks, however, are not intended to be derogatory of either volume. Few texts have appeared which so completely meet the ideals of those who have been filling the pages of THIS J o u n ~ u with . pleas for a moremodern treatment in the freshman course. Unlike many texts which pay lip service to modern theoretical developments in the earlier sections and lapse into the obsolete traditional viewpoint in the later chapters on descriptive chemistry, "General College Chemistry" is from start t o finish consistently modern and up to date. I n the chapters devoted t o the chemical elements and their reactions the theories elaborated in theearlier sections areused consistently t o explain the ohsemations, thus affording greater opportunity for genuine understanding. While the hook may seem excessively long t o many teachers, it should serve the student adequately as a reference book for his courses in qualitative and quantitative analysis and as a permanent additon to hischemicallihrary. Thereferencesfollowiug the chapters have been carefully selected and it is gratifying to supporters of THIS JOURNAL t o note how many have been selected from its pages. The reviews of "General Inorganic Chemistry" were very favorable and teachers may feel no hesitancy in selecting the present volume, "General College Chemistry," for students of hetter-than-average ability. LAURENCE S. FOSTER
Barnett F. Dodge. CHEMICAL ENGINEERING THERMODYNAMICS. Professor of Chemical Engineering, Yale University. McGraw-HillBook Company, Inc., NewYork, 1944. xviii 680pp. 182 figs. and 1chart. 25 tahles. 15 X 22.5 cm. $6.00.
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Professor Dodge dedicates this baok t o his wife "who mites more exciting books." And, the present reviewer would add, hooks that are much easier to read. This h w k has been long in the making. Professor Dodge confesses t o 15 years; a t least 10 years ago he ventured a promise t o write the hook. Now he apologizes for having written it, hoping that there is r w m for this onemore text on chemical engineering thermodvnamics. , - ~ So far as the oresent reviewer and teacher of chemical engineering is concerned, them is still plenty of room in the field. Particularly there is neded now a textbook which will prepare the undergrnduntc to tackle Professor Ihdge's book in his senior year. I f a competent chemical engineer could be prevailed upon t o write a first-class textbook of physical chemistry for chemical engineering students the latter might then indeed be familiar with those "fundamentals that are in the curriculum of the first three years of any good undergraduate course in chemical ~
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engineering." Perhaps a "gwd undergraduate c a m e in chemical engineering" could be defined as one which adequately prepares a student t o use Professor Dodge's thermodynamics text in his senior year. I n any event, the senior who wades through this hook in the course of a year will know that he has gone places. The plan of the hook is set forth clearly in the Preface, from which the following excerpts are quoted: "The &st two chapters are devoted to developing the fundamental concepts and definitions and especially the ideas underlying the two great laws of thermodynamics." . "Once the concepts are presented, their development into usable tools becomes a purely mathematical problem, and this is themethod of approach adopted in Chapter 111.". ."The next logical step was to extend the development t o more complex systems, and that is the business of Chapter IV.". . "After developing differential equations relating thermodynamic properties to the variables of state, the equations must he integrated. This requires put data, and so the neat logical step is t o review suchdataand the equations of state for expressing them. Thisis the task of Chapter V. Chapter VI then brings thedifferential equations and the means of integrating them together and develops the numerical calculation of the thermodynamic properties. The first six chapters have laid the foundations far the applications t o specific operations and processes that constitute the subject matter of the remaining seven chapters." The plan above outlined has been executed with care and precision. The inclusion of 135 solved problems will he extremely helpful to the student (perhaps even t o the teacher). One could wish that the author had included another 135 prohlems, formulated but not solved in the book. Correct answers to hastily formulated prohlems are often an embarrassment t o a lazy teacher. The ahundant references t o original articles constitute a valuable feature of the book. There is little that one may criticize in this book. I t is not evident t o the uresent reviewer that there is anv compensatlnp advantage fur tile au kward srhrmc adopted in n;rnherinp the figwe, and equations. Here and there in the text the language used is not as crisp as it might be. For enample, in the &st paragraph of the book, the phrase "may he said" in lines one and eight serves no useful purpose. On page 13 why say "This simply means"? And why say "the well-known equation of the di5erential calculus"? On page five the author might well h a v e indicated that the identity of the ideal gas temperature scale and the thermodynamic temperature scale is not accidental. I f Professor Dodge can predict what a nowd or large group of individuals will do, as he sugpegts on page 9, he is swely wdsting his time teaching chemical engineering. The abovementioned criticisms, and many similar ones which might he made, are trivial. Professor Dodge has produced a very excellent hook, one which will he useful both as a textbook and as a reference in chemical engineering. May its kind increase! HARRYA. C m s
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UNIVBPSITY OI MIBSLIOB~ COLVYBIA. MZSSODR~
T s a c n ~ n saon OUR Tlaa~s. A Statement of Purposes by the Commission on Teacher Education. American Council on 178pp. 15 X 23 Education, Washington, D. C., 1944. xix em. $2.00.
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The purpose of this baok is t o show the kind of teaching schools and kind of teachers the country needs. To this end the Commission makes three surveys: the existing conditions surrounding the teaching profession, including types of teachers and types of preparation; the social and economic trends of the country; and the types of students. The conclusion is "that the purpose of teacher education is to produce good teachen, that excellence in a teacher is relative t o the tasks that he ought t o perform, and that those tasks should he determined with reference to the changing needs of children and thesociety in which the teaching is t o be done."
