RECENT BOOKS PHY~ICAI. SCIENCE. W. F. Ekret, Professor of Chemistry. Editor; L. E. Sfiock, Jr., Associate Professor of Geology; W. A. Schneider, Assotiate Professor of Physics; C. W. van der M e w , Professor of Physics; H. E. Waklret, Instructor in Mathematics, Collaborator, New York University. First Edition. The Macmillan Company, New York City, 1942. x 639 pp. 295 figs., 28 tables. 15 X 23 cm. $3.90. The main purposes of the book are clearly described, "to provide a broad background of knowledge of the physical sciences which is essential to the culture of an educated man if he is to anoreciate the world of todav. ,. and to nrovide same understandine of the scientific rncthod and the neceaiity for its use to attain c l a r , logical, mhinscd, and arcuraru thought in any Keld of human cndcavor, ns rvrll as in science. We shall consider the basic concepts of astronomy, chemistry, geology, and physics, and some of the ways in which these subjects are interrelated. The use of mathematics as a guiding principle and also as a tool will be made clear." The reviewers share the conviction that the accomplishment of these purposes should be within the ambition of modem education. The major problem in a textbook or a course of study is always the choice in emphasis between subject matter on the one hand and, on the other, the spirit and methods of science. A second, almost equally significant dilemma, is the choice between focus on established fields of study and diffusion on the essential unity of science. The resolutions of these choices, as represented in this book, make it the best introductory textbook in physical science that has come t o the attention of the reviewers. The choice of the subject matter in the various fields is discriminating and well integrated, the treatment is professionally sound, clear, logical, and as rigorous as is consistent with the elementary treatment with a few exceptions which will be mentioned later. There are plenty of well-drafted and well-chosen figures, exercises, and oroblems. and some, though not enough ~erhaos.illustrative examples~workedout in detail. The referkces-at the end of each chapter are well selected. The value of the book might be improved by the use of a larger number of pictures of physical scientists than the four given in the book. The chapter on The Scientific Method has good discussions of the role of observation in science and of the nature of inductive and deductive reasoning. Later chapters on Science and Measurement, Discovering Scientific Laws, and the Nature of Scientific Reasoning present a good picture of the way the scientist works and thinks. The method of science should appear from this more clearly than from the discussion in most elementary textbooks. One might quarrel with some aspects of it; for example, the role of assumptions and laws are discussed in the last chapter of the book. Here the postulates of Dalton's atomic theory are called "fundamental laws" in the same sense as are Newton's laws of motion. There are places where one could wish the authors had dealt a little differently with a particular subject. The statement about simificant fieures near the bottom of oaee 13 is usable but " very cumbersome. On the other hand. the statement-"When this mea-ured quantity is used i n calculat~ons.the results are also expressed in a manner which implies n u greater accuracy than is inherent in the original measurement, that is t o say. the calculated result will be expressed to three significant figures"-is not rigorous in that the Last clause is valid o n b if the calculated result isobtained by multiplication or division;it is not valid for addition and suhtraction. Also the statement of Newton's second law of motion can give a false impression: "The measure of the force which has acted on an object to alter the state of its motion is the product of the object's mass by the acceleration produced." This can lead a student t o the conception that a force has t o act for a considerable time to produce the acceleration. The acceleration exists while the force is acting and not after i t "has acted."
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The discussion of the second law of thermodynamics is good. Many elementary textbooks avoid dealing with i t because of its difficulty but that is an evasion that does not seem justifiable when we consider that the second law and the laws of conservation of mass and energy are the most generally applicable laws that have been stated in physical science. While the authors have correlated the various fields of physical science surprisingly well, there are still instances where the correlation could be much improved; for example, in the discussion of cosmogony, the authors are content with purely descriptive material of the universe outside the solar system and raise the question of origin only in respect to the solar system. The grand perspective of time and evolution-ne of the principal lessons of the physical sciences-odd have been emphasized by relating earth-origin hypotheses t o the studies of extraealactic nebular evolution and the ideas of stellar evolution. " Alrhougl! these studin are in a highly inconclusive stste, rhar is equally true of the current spfr~nlationon the evolution of the solar system. One hundred and fifty-four pages of the b w k are devoted t o strictly chemical subjects. The chapter headings include: Chemical Changes. Oxygen and Hydrogen, Water and Solutions. Chemical Equilibrium. the Periodic Classification. Metals and Metallurev. Salt and ~imestone.Heavv chemicals. and Com~
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X-RAYCRYSTALWGRAPW.M . J. Buerger, Associate Professor of Mineralogy and Crystallography, Massachusetts Institute of Technology. First Edition. John Wiley and Sons, Inc., 531 pp. 252 figs. 15 X 23 cm. New York, 1942. xxii
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This book is written primarily for those wishing to determine crystal structures, using single crystals and monochmmatic x-rays. For such people, the reviewer recommends it very highly. Experimental methods and the pertinent theory are clearly and accurately described in considerable detail. Related fields, such as x-ray physics, crystal symmetry theory, the results of crystal structure analysis, and crystal chemistry, are (quite properly) entirely omitted from consideration. Obviously. the b w k is not of much interest to those not actuallv workine-r about tostart work-in the field with which it deals. The publi-hws, like the author, a r t to be commended for doing an excellent job. ~~~~
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I S O ~ R I W T I OOP N Puag HYDROCNUIONS.Gustan Egloff, George Hulla. and V. I. Komarewsky, Universal Oil Products Co. Research Laboratories and Illinois Institute of Technology. A. C. S. Monograph Series. Reinhold Publishing Corp.. New York, 1942. 499 pp. 15 figs. 15 X 23 em. $9.00. Isomerizatiou of hydrocarbons is becoming more and more important in the war e5ort. The alkylation process, which is the mainstay of our 100 octane gasoline production, requires large amounts of isobutane. Tomeet the demand, acommercial process for producing isabutane by isomerking n-butane has been developed. In addition, many of the naturally occurring hydrocarbons present in gasoline have low octane numbers, which can be increased by isomerizing them to more highly branched hydr* carbons. Ole& isomerization may become important in p r o dncing raw materials for synthetic rubber production. The authors of this volume have naturally emphasized the application of isomerization t o the petroleum industry. The scope of the work is much broader, however, and they have
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