Recent Books A Laboratory Manual of General ChemAND ANLEONB. RICHARDSON DREWJ. S C A R L E ~ JR., , professor^ of Chemistry in Dartmouth College. Henry Holt and Company, New York, 1928. vi f 57 pp. 13.5 X 21 cm. 80.90.
istry.
We are familiar with two extreme types of laboratory manuals. I n one, numerous short experiments of a descriptive nature are outlined with little or no discussion of the principles of chemistry. I n the other type there are only a few experiments outlined and they are of either a quantitative nature or in some other way designed t o develoo the theoretical side of the suhiect. This manual is made up of a very good combination of descriptive experiments and experiments of a nature such ss t o aid the student in an understanding of the theories of chemistry. There are a total of fifty-four exercises planned, many of which are made up of a number of short tests of the "test tube" type. The first three are directions for glass working, measurements of gas volumes,and weighing. The students' time is conserved by the inclusion of blank pages for notes and tables for the recording of data. The manual was prepared to accompany "General Chemistry" by Richardson, and numerous references t o the text are made. The directions are clear and concise, hut are rather abrupt. The reviewer would prefer that directions for an experiment be prefaced with a hrief discussion which would suggest t o the student a reason for performing the experiment. No such introductory matter is included by the authors. Their method is t o give directions and then ask questions on the significance of the results. The consecutive order of the exercises may perhaps best be designated as "conventional," unless one considers the plac-
ing of the experiments with sulfur before those dealing with chlorine an exception. Ionic equilibria and solubility products are well emphasized in the experiments with the metals. S ~ R W MASSER IN UTAHAGRICULTURAL COLLEGE Chemical Calculations. J. S. LONG,Ch.E., M.S., Ph.D., AND H. V. ANDERSON, B.Ch.E., M.S., Lehigh University. Second edition. McGraw-Hill Book Co., New York, 1928. ix 227 pp. 11 figures. 20 X 13.5 cm. $1.75. postpaid.
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This is a second edition of a hook which first appeared in 1924. It consists of fifteen chapters, dealing with such prohlems as thermometric calculations, density of solids and liquids, gas laws (including Dalton's law of partial pressures), definite and multiple proportions. GayLussac's law of combining volumes, grammolecular-volumes,derivation of formulas. halancing of oxidation-reduction equations by change in valence, normal solutions, gas analysis, thermal equations, electrolysis, mass law, and solubility products. The appendix contains tables of data useful in solving the problems. Each chapter contains a hrief discussion of principles, followed by ample lists of numerical problems, with and without answers. I n the preface the authors state that these problems were originally designed for use in the second half of the freshman year, using weekly recitations. The lists of problems appear large enough t o furnish a supply for three or four years' work, without repetition. The exercises are well chosen, and appear t o he arranged with a view t o increasing difficulty. They show as much variety of form as might he expected. The numerical quantities used are seldom
