determinations of chloride and sulfate, the analysis of certain minerals such as feldspar, dolomite, and chalcopyrite; phosphate by the molyhdate method, separation of iron from manganese by use of hexamethylenetetramine, separation of arsenic by distillation as chloride, a bromometric method for antimony, and a calorimetric (sulfide) method for small amounts of lead. Magnesium is precipitated and weighed as magnesium 8-hydroxy quinolate.

Eleetroanalysis covers more ground than is usual in elementary manuals. It includes a determination of copper, separation of copper from nickel, separation of silver from copper by use of graded potential, use of rotated anode and mercury cathode, and, finally, determination of capper, zinc, and tin by a combina- tion of gravimetric, volumetric, and electrolytic methods.

The electrometric titrations include pennanganic-iron and a silver titration for mixed iodide and chloride.

The procedures are clear and concise, and the work of transla- tion has been well done. The translators recommend this hook because it pays very little attention to physico-chemical explana- tions, claiming that the late trend in this direction is unfortunate because too little time is left for development of technic. The reviewer must take issue with the translators at just this point. If there is any branch of chemistry which has profited by applica- tion of physical chemistry i t is certainly analytical. In fact, there are many analytical processes which can neither be ex- plained nor well done without the use of physical chemistry. I t is true that analytical chemistry is an art, but i t is also a science: and i t seems very unfair to lead a stndent to think that the manipulative side is the more important. Moreover, it is not true that a proper teaching of the scientific side leaves too little time for the manipulative side. The one is taught largely in the classroom and the other in the laboratory, and the latter will not be neglected if the teacher is "on the job." Again, a student who has been given the proper scientific background will Learn the practical side much more readily, because he sees ihe reasons for the procedures. W. H. CHAPIN

O s s n ~ m COLLBGB OBBI-LIN, ORID

CRYSTALS AND THE P O ~ I S I N G MICROSCOPE (A Handbook for Chemists and Others). N. H. Hartshorne and A. Stuart of the University College of Swansea. Foreword by G. T. Morgan. Edward Arnold and Co., London (Longmans, Green and Co., New York City), 1934. viii + 272 pp. 217 figs. 14 X 21.5 cm. $6.00.

This rather small book by a chemist and a geologist, excellently illustrated with line drawings, succinctly and carefully covers its subject. Chapter beadings (with number of pages to each) follow: I, Crystalline State (7); 11, Morphobgy (41); 111, Optical Properties (43); IV, Polarising Microscope (29); V, Parallel Light Examination (46); VI, Convergent Light Exami- nation (48); VII, Examples of Use (13); VIII, Methods and Experiments (29). As is to be expected, the major portion of the book is given over to optical methods. The section on morphology, however, is treated at satisfactory length. It covers indices of faces, habit, cleavage, twinning, and lists the 32 classes with their symmetries (and examples) by systems.

Chapters III-VI call for no particular comment as regards contents and arrangement, though one is very favorably im- pressed in respect to clarity of exposition, accuracy, and com- pleteness of coverage. Chapter VII cites and briefly describes over 50 published examples of the use of the polarizing micro- scope in inorganic and organic studies, giving a fair idea of their variety, but is of course far from exhaustive. The final chapter (followed by a page of references to determinative tables and an index) summarizes in systematic fashion the methods of study of non-opaque crystals and describes 14 experiments to be carried out on laboratory-grown crystals which serve to illustrate well the principles covered in the book, including the special value of optical methods in attacking certain chemical problems.

While the hook is remarkably free from errors, same were noted. These and some controversial points are as follows:

p. 5,l. 2--cryst$s of class 1 show no symmetry. p. 23,l. 11-(111) is read "one one minus one." pp. 37, 3Wlasses 19 and 22 are hexagonal. not rhamho-

hedral. p. 44--hexagonal pyramidal means 6 (not 3) cleavage planes;

tetragonal prismatic means 2 (not 1). p. 89-X-ray workers place Ba(N0a)s in class 30 (p. 40;

= Tc = Pa3); this may account for its lack of optical activity.

p. 132-"twinkling" is an interesting term; defined on p. 150. p. 144.1. 23-refractometers extending well above 1.70 are not

uncommon. pp. 153 st sep.-fir used in place of mr. p. 157-y used in place of 7. pp. 158 et ssp-"optic normal section" is used to mean a

section containing the optic axes, because the optic axes are then normal to the axis of the microscope (p. 182). "Optic axial section" is used for one normal to an optic axis.

p. 159, I. 2&@arallel is better than straight (extinction). p. 160, Fig. 147-010shouldread 001. p. 169--formula of diopside does not agree with that on p.

160; formula of microcline is erroneous; trace of pericline twinningon 010 (Fig. 159) is too steep for plagioclase.

These comments are all rather minor and do not serve to detract seriously from the value of the book. Any teacher willing to cover optical methods with polarized light in a course separate from (and presumably preceding) one on general microchemical methods will find this book different from any in English known to the writer, and careful examination is unreservedly recom- mended.

The tariff on scientilic books apparently operates in this case, as in so many others, to increase by 50 per cent. the cost of a text of great potential value in the United States.

TEE u ~ ~ v e ~ s r r v OF cnrc~oo D. JEROME FISHER C~1C100. ILLINOIS

BIOCKEMICAL LABOMTORY METHODS FOR STUDENTS OF THE BIO- LOGICAL Scm~css . Clarence A. Morrow, Ph.D.. Late Assist- ant Professor of Agricultural Biochemistry, University of Minnesota, and William M. Sandstront,,Ph.D., Assistant Pro- fessor of Agricultural Biochemistrf,'University of Minnesota. John Wiley & Sans. Inc.. New York City, 1935. xv + 319 pp. 38 figs. 12 tables. 15 X 23 cm. 53.75 net.

This laboratory manual is designed to accompany Gortner's "Outlines of Biochemistry." The opening chapter deals with the colloidal state; the classes of colloids, and their behavior, diffu- sion, hydrogen-ion concentration, and surfice phenomena in solutions are illustrated with an extensive series of experiments. Then follow chapters on Physical Chemical Constants of Plant Saps, Oxidation-Reduction Potential, Proteins. Carbohydrates, Glucosides and Tannins, Fats and Allied Substances, Enzymes, and Plant Pigments. There are many experiments on the prepa- ration of individual amino acids, their estimation, and the prepa- ration of their derivatives. In addition to the conventional exer- cises on the carbohydrates there is an excellent section devoted to the pre~aration of unusual sugars. The material dealing with plant pigments touches upon topics of interest to students of nutrition.

In many instances the directions for the experiments are pre- ceded by a discussion of the principle involved or the significance of the topic, and a t the end of every experiment is a list of per- tinent references. The directions are clear while at the same time the student is compelled to call more or less an his own resources and experience. There is a conspicuous lack of con- sideration of biochemistry of animal tissues and body fluids; in other words, there is little appeal to those to whom bio- chemistry means medical chemistry. Nevertheless, this new edi- tion represents a distinct contribution to the teaching of general biochemistry. ARTHUR H. S M I . ~

YALE UKIYBBS* NEWHIYEN, CONNBCTICWT