396
NEW BOOKB
published) for a number of the methods; these will be welcomed by analysts who have had difficulty with some of the procedures. Microchemical applications, both qualitative and quantitative, have been extended, and both these and macro methods have been adapted to a wide variety of technical processes. The colorimetric methods are of interest, but their utility is often restricted by their lack of specificity. Thirty-one metals now come under the sway of “oxine,” and the different conditions of precipitation lead to many useful separations which are clearly set out. In some cases, however, e.g., that of lanthanum and niobium (columbium), the metals cannot be separated from their congeners, and the methods are of limited value. A minor, but annoying, defect is the carelessness in the spelling of names: Pregel for Pregl (page 33), Nieszner for Niessner (page 28), and even (page 3) Berd for Berg! The index rectifies these errors but adds others. Also, on page 2 the Journal of the American Chemical Society is given instead of the English Journal of the Chemical Society, and on page 51 the converse error occurs. A. D. MITCHELL.
The Ozidation States of the Elements and their Potentials in Aqueous Solutions. By W. M. LATIMER. 352 pp. New York: Prentice Hall, Inc., 1938. Price: $3.00. This book gives more than the title indicates. As stated by the author, the primary object of the work is to gather together the large mass of free-energy data which is scattered throughout the literature and t o present i t in a simple form as an aid in the interpretation of inorganic chemistry. Moreover, solubility products and the dissociation constants of many acids, bases, and complex ions have been included. In calculating many new free energies from reaction heats Professor Latimer has drawn largely upon his own experimental work on the entropies of solids and aqueous ions. The author has succeeded well in the task that he set himself and has presented us with an authoritative text, which satisfies a long-felt need in physical, inorganic, and analytical chemistry. Anyone interested in the states of oxidation of elements will 6nd the wealth of information to be obtained from this text invaluable. The first chapter is introductory and deals with units, conventions, etc. Unfortunately, the expression of the activity as given on page 2 (ninth line) is not very exact. The second chapter is of a general theoretical nature and discusses briefly the relation between oxidation potentials on the one hand and ionization potentials, electron affinities, hydration energies, and lattice energies on the other. This chapter might be enlarged with advantage; reference could have been made t o R. W. Gurney’s book Ions in Solution. Although it is specified in the title of the book that only potentials in aqueous solutions are considered, the solvent effect might have been discussed in the second chapter. The remaining nineteen chapters deal with an exhaustive treatment of the states of oxidation of the various elements. On page 29 reference might have been made t o Heyrovskq’s theory of the overpotential of hydrogen and deuterium. Especially in the chapter on carbon, results obtained with the dropping mercury electrode could have been referred t o with advantage. The book is remarkably free from misprints; on page 189 the reviewer noticed that Thiel’s name was misspelled several times. The summaries of oxidation potentials, free energies of formation, equilibrium constants, activity coefficients, and entropy values in the appendices are valuable. This book, undoubtedly, will receive the recognition and wide circulation that it deserves. I. M. KOLTHOFF.
