Recent Books lina, and P a m M. O-noss, Head of the General Science for Reviews. W. DEAN Department of Chemistry, Duke UniPULVERMACHER, M.A., LLB., Chairversity. First edition. Longmans, man, General Science Department, Green and Co., New York, 1929. riii Jamaica High School, New York City, 466 pp. 88 figures. 13 X 20 cm. M.A., and CHARLESH. VOSBURGH, $3.75. Principal, Jamaica High School. Globe Book Company, New York City, 1929. I n the preparation of the hook the 125 pp. 68 illustrations. 12.5 authors "have had in mind the college ii X 18.5 cm. $0.50. student who takes up the study of physical This little manual, prepared for review chemistry after the usual courses in genpurposes, includes in fifteen chapters es- eral chemistry, analytical chemistry, and sential topics in general science suited to organic chemistry, and who has had a pupils in the intermediate schools. The course in general physics and preferably topics are presented in simple language in thecalculus. * * * * The book is frankly and are illustrated by simple, wel-drawn elementary, for it is designed t o accomfigures. Appended t o most of the chap- pany a year's course of two lectures a ters is a series of questions designed t o week." Fourteen laboratory experiments exercise the thinking powers of the pupil. requiring three laboratory hours each Key experiments are made the basis for week are included. The text should he a teachable one, much of the work. Chemistry, physics, astronomy, and various phases of biology appealing t o the student, for it is, in are represented by chapters or exercises general, clearly written, and it endeavors under chapter headings. To the reviewer t o present a fbgical outline of the general it seems that somewhat too much em- principles of physical chemistry. Since phasis has been placed upon the biologic the chapter on thermodynamics immeaspect, but perhaps a chemistry teacher diately follows the discussion of gases, its principles are quite naturally and logically is hardly a fair critic on this point. The sixteenth chapter deals with same utilized in the discussion of the vapor of the newer types of examinations, while pressure of liquids as well as in later work. the remainder of the book presents a The inevitable mathematics is so intrdnumber of recent examinations in general duced that it is no more temfying to the science given, supposedly, by the Board student than the same simple algebra and of Regents. There are no appendices or calculus in a mathematics course would be. Much material of specialized interest and index. Teachers of general science who desire a most of that of solely historical interest is small manual for use in reviewing the ele- omitted; part of the matter will he a mentary phases of the subject will do well review for those students who have studied some of the general principles in their to examine this little volume. general and analytical chemistry courses. C. H. STONE Far such classes, teachers would probably ENCIJS" HIC" SEWOO~. ROSTON,MASSACHUSITTS wish to supplement the text with additional material. Elements of Physical Chehistry. JAMES The parts of the text dealing with the M. BELL. Head of the Department of use of thermodynamic equations in calcuChemistry, University of North Caro- lations are not up to the standard of the
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rest of the hook. In the chapter On thermachemistry the authors consider heat evolved as positive, and in the thermodynamic derivations they use heat absorbed as positive, hut nowhere is this change in convention explicitly stated. The who wishes to correlate the ...- -student day's assignment with his previous work will therefore find on page 78 that heat a t constant pressure equals heat a t constant volume minus the work done, and on page 304 that heat a t constant pressure equals heat a t constant volume @Gusthe work done. If he substitutes the data for the dissociation of nitrogen tetroxide, given on page 306,in the integrated van't Hoff equation on page 305, he will not check the authors' calculation, for they, without explanation, use Q in this example as heat aolued, though in the next example Q is used as heat absorbed. He will find the same uncertainty on pages 372 and 373. The good student will desire to have conventions suggested which enable him to calculate, from a given set of data, the directionas well as the magnitude flow. The book is free from typographi~al errors. Among the oversights, however, is the discussion (page 352 et seq.) introducing "Henry's law," although the law is left undefined. The use of the logarithm tables in the appendix would he facilitated if the parts of a table were printed facing each other, and not on both sides of a leaf. Some teachers would prefer to have included in the paragraph on the methods of expressing solution concentration, the expression in terms of mols per 1000 grams of solvent; others would qualify the statements on the conservation of mass in the light of modem physics. The student might well be told that the "triple point" for water is not exactly a t O'C. and the reasons why it is not. These latter criticisms are of secondary importance. The teacher who has a limited time in which t o introduce a class to some of the principles of physical chemistry should examine the hook. L. E. STEINER OBSRLINCOLLBUB OBHRLI-IN, orno
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Practical Chemistrg by Micro-Methods. EGERTON CHARLES GREY,D.Sc., F.I.C. (Lond.), M.R.C.S., Professor of Chemistry. Government Medical School, Cairo. W. Heffer and Sons, Ltd., Cam124 pp. 16 illusbridge, 1925. ix trations. 13.5 X 21.5 cm. 4s. 6d. net.
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The purpose of the book may best be judged by quotations from the preface: "It must be evident to many that the time has come for a change in some of the methods of teaching practical chemistry. Classes seem to get larger every year . many experiments which could once be performed hy.each individual must perforce he omitted, and there is a tendency t o meet the situation by adapting the practical course t o the convenience of the laboratory rather than t o the individual The method of needs of the students. practical microchemistry is that of working with minute quantities of material. specks of solids, drops of liquids. With this method the difficulties which would hamper many a laboratory will be found There is nothing which a t to vanish. present is done by students with large a paratus that cannot he done with the r9 m~cro-method,hut there is much that can be done with small apparatus that is a sheer waste when done an the larger scale. . A student's whole outlit may he put upon a tea-tray, and with all his laboratory thus a t hand the student may sit down t o his wark with consequent sparing of fatigue to himself and t o his teacher.. . The methods of microchemistry are exceedingly rapid. .With this sparing of time i t follows that much more work can The he gat into the working hours. economy also in energy and in expense is enormous, with the result that i t is possible t o cover a much broader field of study. . This hook is intended for schools or for the earlier part of a university course and it covers the practical wark required by the conjoint hoards of the Royal College of Physicians and Surgeons. While describing the methods of microchemistry, i t indicates also how a practical course may be broadened to include exercise in
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