NEW BOOKS T. READ. Century of Progress Series. Our Mineral Civilization. By THOMAS 5 x 7 in.; 165 pp. Baltimore: The Williams & Wilkins Co., 1933. Price: $1.00. The author is a well-known writer in the field of mining engineering. The treatise on this subject is exceptionally well written and should be especially interesting to people who have not been trained as scientists and engineers. The development and uses of the commercial minerals, important chemical elements, metals, and their alloys as applied by mankind is presented by the author in an interesting, clear, accurate, and concise manner. There are statistics, but not enough to bore the reader, and the general philosophy, economy, and comparisons remind one, t o some extent, of the book Creative Chemistry by the late Dr. E. E. Slosson. R. L. DOWDELL.
Sdure-Basen-Indicatoren. Ihre Anwendung bei der colorimetrischela Bestimmung der Wasserstofionenkonzentration. VON I. M. KOLTHOFF unter Mitwirkung von 13.5 x 20.5 om.; xi + 416 pp.; 26 figures. Berlin: Julius HARRY FISCHGOLD. Springer, 1932. Price: 19.8 RM (geb.). This volume, issued under a different title, is a much expanded fourth edition of Der Gebrauch uon Farbindicatoren. The work is divided into three parts. The first two sections, i.e., “The dissociation of strong and weak electrolytes” and “The properties of acid-base indicators” contain an excellent discussion of the theory and modern viewpoint of these subjects. The third section dealing with “The colorimetric estimation of hydrogen ion concentration” contains the applications of the theories which have been developed t o problems of practical application. Probably no one is better qualified to write a handbook such as this than is Dr. Kolthoff, for it represents a field t o which he has given major attention for a number of years, both as a research worker and as a teacher. The theoretical discussions go beyond most books which are designed to cover this field and include lucid discussions of the recent trends in the “activity” concept, including a thorough discussion of Bronsted’s ideas on acid-base function. Bronsted has rightly pointed out that the hydrogen-ion, being a naked proton and accordingly an a particle, cannot exist as such except for an infinitesimally small length of time, that it will penetrate into the electron shell of the first molecule it comes in contact with and, thus associating itself with a neutral molecule, will form a molecule possessing a positive charge. Thus instead of speaking of “hydrogen-ions” we should more properly speak of the “hydronium ion concentration,” (Haof),which represents the concentration of the solvated protons. The Bronsted definition of acids and bases differs considerably from the older conceptions, but appears to possess real merit. Thus “an acid is a substance which is able t o split off a proton, simultaneously forming a base, and a base is a substance capable of uniting with a proton, thus forming an acid.” Thus the dissociation of an acid in water may be written A
+ Ha0 ?r B- + HaOf
acid
base
base 401
acid
402
NEW BOOKS
This concept lays primary emphasis on the sign and magnitude of the charge of the central atom of a molecular configuration as determining acidic or basic properties rather than the criterion of “salt formation” which is regarded as an incidental phenomenon. The present volume is especially valuable since it discusses acid-base dissociation in such solvents as ethyl alcohol. On the basis of Bronsted’s definition both ethyl alcohol and water are bases, but water is four hundred times as strong a base as is ethyl alcohol; this accounts for the difference in behavior between aqueous and alcoholic systems. This section of the book especially appealed t o the reviewer. In the section devoted t o the properties of indicators we find an excellent theoretical discussion, followed by a description of the various indicators, including formulas, melting point, and other physical properties, methods of purification, solubility and p H range and their suitability for use under various conditions and with various solvents. A new definition of an indicator is proposed, i.e. “Indicators are (apparently) weak acids or bases, whose inogene or aci- (or baso-) form possesses a different color and structure than the pseudo or normal form.” The third section of the book, dealing with the colorimetric estimation of hydrogen-ion concentrations, deals with the preparation and properties of buffer solutions, the technic of the colorimetric determination of hydrogen-ion concentration, the sources of error in the colorimetric methods, including an extended discussion of the effect of salts, proteins, and other colloids, temperature, etc., with the last chapter devoted to indicator papers. The book closes with an appendix of six tables showing the ion product of water a t various temperatures, the ion activity product of water, the activity coe5cient for various concentrations of electrolyte solutions, an extensive table of the dissociation constants of approximately one hundred and twenty acids and bases, including such compounds as the alkaloids, phenols, etc. (The reviewer wonders why the amino acids were omitted from such an imposing list, for they certainly are more commonly worked with than are many compounds included in the table), and an interpolation table for converting fractions of pH into Ca values. Excellent author and subject indices close the volume. It is a book filled with valuable discussion and tabular data. The fact that other volumes on the determination of hydrogen-ion concentration are available should not deter one from purchasing this book, for it contains much material not otherwise readily accessible. It should be in every chemical library and in the hands of everyone interested in the control a,nd measurement of hydrogen-ion concentration. Ross AIKENGORTNER.
Die Struktur der Atomkorne. By DR. SIEGMUND 22 x 15 cm.; 50 pp. STRANSKY. Leipzig u. Wien: F. Deuticke, 1932. Price, 4s. 9d. Dr. Stransky’s monograph on the structure of the nucleus is entirely original and entirely speculative. There is evidence in favor of the conclusions he draws but it is of a numerical kind, in which the numbers are confined rigorously t o integers. He does not consider other theories of the subject he is writing about, and it is at once patent t o a reader t h a t little reconciliation is possible between Dr. Stransky’s views and the main corpus of knowledge that has been ground out of the research of the past twenty years. They lie, indeed, so far outside of the main stream of theory and experiment t h a t I fear atomic physicists may fail t o give them the patienl consideration the author would like them t o get. Dr. Stransky is a modern Prout, a Prout, moreover, who has had in his time thf discouragement of a Newlands. He tells us that for forty-five years he has occupiec himself a t invervals in arranging units of mass (protons, they would now be called: in such patterns that the most likely of them sum to the masses of the common ele ments, and that he has not always been able to get his work published. Like Prou
