Contributions to Chemical Education. Number Two. The Polarographic

Publication Date: August 1942. ACS Legacy Archive. Cite this:J. Phys. Chem. 46, 8, 1008-1009. Note: In lieu of an abstract, this is the article's firs...
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?JEW BOOKS

simple rotating- and oscillating-crystal methods, and detailed treatments of the increasingly important moving-film methods-especially the Weissenberg, Sauter, Schiebold, and de Jong-Bouman methods. The latter have been available only in the original literature in the past. The treatment throughout is based on the reciprocal lattice, which is presented very completely. A very escellent chapter on precision in the determination of lattice constants deserves special mention. Finally, it gives many experimental details which have never appeared in the literature. The book requires little background, inasmuch as such subjects as elementary lattice theory, x-ray diffraction, space groups, etc. have been treated in a gradual manner. Where possible the author presents ideas requiring space geometry, first in terms of an example in a plane. Another excellent) feature is the inclusion of all the intermediate steps in the mathematical derivations. In the case of crystallographic proofs customarily given in vector algebra, alternate proofs are presented by geometrical and algebraic methods. The typography of the book is excellent, and the drawings are the finest the reviewer has ever seen in books in this field. I n spite of the large amount of mathematical detail it appears to be remarkably free from errors. I t is to be recommended without reservation whatsoever, and workers in the fields of x-ray diffraction and crystallography will find i t a “must” for their book shelves. HAROLD P. KLUG.

contributions to Chemical Education. Number One. Acids and Bases. .4 Collection of Papers by N.F. HALL,H . T. BRISCOE, L. P. HAMMMETT, W . C. JOHNSON, H . N . ALYEA, 1.P. MCREYNOLDS, T. H . HAZLEHURST, ANn W . F. LUDER.5 x 8 in.; vii 103 pp. Easton, Pennsylvania: The Journal of Chemical Education, 1941. Price: $1.00. The first four articles in this booklet are papers presented in the symposium arranged by the Division of Chemical Education a t the Spring Meeting of the American Chemcal Society in 1939, in which the modern definitions and conceptions of acids and bases were discussed. These papers and a number of other articles on the same subject (with the esception of one) which are collected in the above booklet have been published in the Journal of Chemical Education. Several of the papers deal with the methods of teaching the modern conceptions and theories of acidity and basicity. One cannot but feel that the answer to the question whether the newer concepts and theories should be taught in elementary courses is not solely determined by the background of the average student, who can assimilate new ideas if clearly presented. ‘Po a large extent the answer is determined by the ability of the teacher to familiarize himself well enough with the new conceptions so that he can present them as a logical outgrowth of older ideas. L. P. Hammett, who has made valuable and original contributions to the subject of acidity, expresses himself as follows on this score (page 25): “Of course, the new theory is difficult to those of us trained in the older theory, but the difficulties me meet do not exist for students who have nevzr met the older theory. Even now my own tongue stumbles over the new terminology, while it slips glibly off the lips of my students, . . . . . ’ I . The other papers in the series deal with general discussions of the behavior of acids and bases in water, amphiprotic, and aprotic solvents. I t has been a happy idea to incorporate the report of the Committee on Somenclature of Acids and Bsses, headed by H. N. Alyea. All the papers are well written and thought stimulating. The editor, S .W. Rakestraw, deserves praise for havingmade available to teachers, students, and all chemists interested in the progress of their science this attractive looking booklet. I . M.KOLTHOFF.

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Contributions to Chemical Education. hrumber Two. The Polarographic Method of Analysis. By 0 . H . Muller. 5 x 8 i n . ; vi 113 pp. Easton, Pennsylvania: The Journal of Chemical Education, 1941. Price: $1.00. This booklet contains a series of papers which have been published in the Journal of

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NEW BOOKS

Chemical Education. The first chapter gives a review of electroanalytical methods. The second chapter describes a simple and inexpensive manual apparatus for carrying out quantitative measurements with the drop6ing electrode. Most of the apparatus is available in well-equipped chemical laboratories. The following two chapters deal with fundamentals of quantitative and qualitative polarographic analysis. The various factors determining the diffusion current (IlkoviE equation), the significance of the halfwave potential, and the analysis of waves are adequately discussed. The last chapter reviews several applications of polarography. The booklet is well and concisely written, and i t is well suited as an introduction to the subject of polarography. Its reading is recommended to students and teachers. On page 66 the author mentions that the “capillary constant” can be determined by collecting the mercury while dropping in air. However, in experiment 8 he gives directions for collecting the drops falling in dilute potassium chloride solution. On page 87 i t is stated that if the unknown is more concentrated than 10-*M, it is usually possible to work with the solution open to air. However, in many cases, the flat second wave of oxygen interferes with the measurement of diffusion currents. The statement on page 98 that a mixture of thallium and cadmium in 1 N potassium cyanide gives only the cadmium wave is incorrect. On page 113 the author states that polarometric titrations have the same shortcomings as sonductometric titrations. However, he overlooks the fact that amperometric titrations can be carried out in the presence of large amounts of indifferent electrolytes, whereas under the same conditione conductometric titrations become much less accurate. I. M KOLTHOFF. Practical Physical Chemistry. By ALEXANDER FINDLAY. 54 x 8+ in.; x

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335 pp.; 124 figures. London, New York, Toronto: Longmans, Green and Company, 1911. Price: $3.00.

This book has gained a well-deserved popularity, as witnessed by the publication of the seventh edition since 1908. In several respects it is quite evident that the first edition dates back to the beginning of this century. Many experiments of the classical type are given which are not found in more modem books of the same character, whereas methods of more recent development (e.g., abridged spectrophotometry with photoelectric reading, dielectric constant, etc.) are not given. Although several additions have been made to the present edition, modem developments in physical chemistry have not always been given due considerstion. This is especially true of the subject of the modem theory of electrolytes (the calculation of the activity from osmotic measurements on page 133 is not correct; Onsager’s equation is not mentioned in connection with equivalent conductance). A new feature of the book is the introduction of the antimony electrode for pH measurement, but the glass electrode, which is much more exact and which fin& much wider application, is omitted. I n a modern book the Langmuir adsorption isotherm a t least should be mentioned in connection with the empirical Freundlich expresclion (page 319). I n spite of its limitations, the new edition, aa its predecessors, excels from the educational viewpoint. The description of the fundamental theory and of the procedures is clear and more than adequate to enable a student to carry out the experiments without much aasiatance. I. M. KOLTHOFF.

Advance8 i n Enzymology and ReEafed Subjects. Vol. I. Edited by E . F. NORDand C. H. WERKMAN.6 x 9f in.; x 433 pp.; 56 illustrations. New York: Interscience Publishers, Inc., 1941. Price: $5.60.

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The Editors have undertaken to assemble internationally recognized authorities to assure expert presentation of the latest developments in enzyme chemistry aa well as related fields. This field has been developed a t such a rapid pace in recent years that