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interesting feature of exhibiting a series of minima at what are believed to be critical concentrations. From these minima Du Nouy and his coworkers have computed molecular dimensions which in some cases are in fair agreement with those obtained by other methods. It is somewhat remarkable that no such peculiarities are observed in the Langmuir trough, and it would seem eminently desirable for a series of parallel experiments to be carried out under identical conditions. A brief account is given of the relationships suggested between capillary activity and various other properties, such as enhancement of membrane permeability, increased sensitivity in the precipitin reaction, and the rates of sedimentation of red blood cells and erythrocytes. It is clear both from the divergencies in views expressed by various workers in these fields, as well as the lack of uniformity in the experimental results, t h a t this is a fertile field ready t o be cultivated by those who possess both the requisite physicochemical and biological experience.
ERICK. RIDEAL. German-English Chemical Terminology. An Introduction to Chemistry in English 21 x 13 cm.; xvii 324 pp. Lonand German. By A. KINGand H. FROMBERG don: Thomas Murby and Co., 1934. Leipzig: Max Weg, 1934. Price: 12s. 6d. The method of this book is the use of English on each left-hand page with German on the right. The subject matter has been selected, from well-known textbooks of both languages, so as to be representative of chemistry as a whole. Original and translation can be compared paragraph by paragrach, and the general accuracy can be relied on, since the book is the joint work of an English and a German chemist. The other feature of this bookis the printing in italics of corresponding terms of both languages on their first appearance in the text, with also an index of these a t the end. The series has been started with geology; under the general editorship of Dr. W. R. Jones, other sciences are to follow. The claim made that such books may be equally useful to both English and German students and that the use of dictionaries is avoided is probably true, provided that each knows something of the other language. It must be remembered that exact translation is not always possible, and that it is often an equivalent which is rendered in the other language. With this in mind such books should prove very useful. W. H. PATTERSON.
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Bilder zur qualitativen Mikroanalyse anorganischer Stoffe. By W. GEILMANN. 23 x 16 cm.; xii 80 pp. Leipzig: Leopold Voss, 1934. Price: 8 RM. I n view of the increasing employment of microchemical tests in qualitative analysis, the present small atlas of photomicrographs comes as a useful addition to the analyst’s library. The work contains close on two hundred and fifty illustrations, reproduced from actual photomicrographs obtained by the author, showing the characteristic forms of the crystals and crystalline precipitates resulting from the various microchemical tests, details of which are briefly given. The difficulty that in the case of many reactions the appearance of the precipitate formed is liable t o vary considerably with the concentration of the interacting solutions, etc., has been met by including in such cases two or more separate illustrations of the precipitates in question, showing their appearance when formed under differing conditions, and thus facilitating their identification. A number of illustrations are also given of certain precipitates, such as zinc ammonium phosphate, which although not in themselves of value as a means of identification, are liable t o be formed during the testing of mixtures, and may easily be misinterpreted. A full index is provided, and the book is well printed, with clear and good illustrations. H. F. HARWOOD.
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