mended chieily t o those readers who have a special interest either in historical chemistry, the electrochemistry of m u aqueous solutions, or in molecular rearrangements. The type is exceptionally large and clear, and the paper and binding of excellent quality. NORRISF. HALL H ~ a v r mUmvaasmw CI(II(B-DB,
MASS.
Identification and Properties of the J. E. Metals and Non-Metals. BELCBERAND J. C. COLBERT,ASsistant Professors of Chemistry in the University of Oklahoma. The Century Company, New York City, 1929. xii 246 pp. 17 illustrations. 21 X 27 cm. 51.75.
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The manual is divided into two parts. The first part consists of twenty-eight experiments in general chemistry and covers 117 pages. The second part contains five additional experiments and an introduction t o qualitative analysis. The five experiments deal with subjects which the reviewer thinks could he more * loaicallv in the first part. . daced The preface sets forth the desire of the authors to "relieve the burdened instructor in grading note-books and a t the same time enable the student to attain the right attitude toward his work." The first part of the manual is very praiseworthy. It deals with experiments on both organic and inorganic substances. Perhaps the name of the volume could be revised with profit. Each experiment contains references t o Kendall's revision of Alexander Smith's "General Chemistry." "The authors of this manual have made it impossible for the student t o answer all of the questions asked on the experiments without constant use of the textbook in the laboratory." The object and materials t o be used are stated a t the beginning of each experiment. It is written in a manner that should tend t o excite the interest of the student and develop his powers of thought and observation.
A novel feature of the volume is the double report sheets for each experiment. By means of carbon paper which is furnished with the manual, duplicates of report sheets are made. The perforated report sheet is to he torn out and handed in. This lessens the burden of turning numerous pages in grading. At the same time, i t allows the student t o keep his manual. The second part of the manual is a very good introduction t o the subject of qnalitative analysis. The appendix contains a scheme of elementary qualitative analysis, numerous tables, problems, and questions which should be very well received. Instructors in general chemistry should find this volume a welcome addition to the list of manuals on the subject. V. T. JACKSON Umvmsrrr o* PLORIDA ,
GAINHS-LB, PLA.
Determination of Molecular Weights in the Vapor State from Vapor Pressure and Evaporation Data. E. W. WAWBURN, Chief, Chemistry Division, mreau of Slandwds. Research Paper No. 53, Department of Commerce. U. S. Government Printing Office, Washington, D. C., 1929. 12 pp. 14.5 X 23 cm. $0.05. "If one determines a t the same temperature the vapor pressure of a substance and the amount of i t required fo saturate, by aspiration, a measured volume of an indifferent gas, the molecular weight of the substance in the gaseous state is calculable. By employing a reference substance of known molecular weight the measurement of the volume of aspirated gas is unnecessary and the quantities measured have small temperature coeficients. A precision discussion of the method is given. It should he capable of a high degree of accuracy in many cases and is applicable a t much lower temperatures than are the methods commanly employed." M. W. G.
