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NEW BOOKS
Gmelins Handbuch der anorganischen Chemie. 8 Auflage. Herausgegeben von der Deutschen Chemischen Gesellschaft. System-Nummer 35: Aluminium, Teil A, Lieferung 1. 26 x 18 cm.; iv 284 pp. Berlin: Verlag Chemie, 1934. Price: 42 Marks. Subscription price: 38 Marks. This volume deals with the occurrence, production, and physical properties of metallic aluminum. The section on its occurrence includes an account of the aluminum minerals, including silicates, and contains a long section on bauxite and laterite, which are used in the technical production of the metal. The section on the production of the metal deals briefly with the older chemical methods and in detail with the electrolytic processes now in use, and with refining processes. The forms of commercial aluminum are described. The physical properties are classified under the headings atomic, crystallographic, mechanical, thermal, optical, magnetic and electrical, and in the descriptions a large amount of numerical data is collected. The volume provides a very exhaustive and authoritative account of aluminum metal both from the physical and chemical aspects, although the description of the purely chemical properties belongs to a later issue. The references are very complete and the literature, which is brought well up t o date, is international. J. R. PARTINQTON.
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T h e Adsorption of Gases by Solids. By S. J. GREW. 17 x 11 cm.; viii 120 pp. London: Methuen and Co., Ltd., 1934. Price: 2s. 6d. The subject of adsorption of gases by solids is one of great complexity and interest, and some reasoned survey of the present state of affairs was much in need. A recent volume published by the Faraday Society indicated that the interest was there, and Mr. Gregg has in small compass given us a detached survey of the subject, admirable in its grasp of essentials and breadth of scope. It is a pity therefore that the series of monographs t o which the book belongs has made it necessary t o deal with many aspects in only a very brief way. Perhaps when agreement has been reached on some of the more controversial items, Mr. Gregg will undertake a larger survey. I n t h e meantime he has managed to pack into one hundred and twenty small pages nine chapters on general characteristics, experimental methods, heats of adsorption, theories, adsorption forces, adsorption layers, surface structure, activated adsorption and, finally, chemisorption. In addition each chapter has its own bibliography, guiding readers t o the original papers of importance. The author’s interest has perhaps centred on the explanations of the many results obtained rather than on experimental method, t o which only a little over two pages have been devoted. In common with other writers on adsorption, Mr. Gregg has failed t o make reference to the practically important process of clean-up, whereby gases are retained at the gettered glass surfaces of vacuum lamps and wireless valves. I n spite of this blemish Mr. Gregg’s book is a well thought out little volume and is worth a good deal more than the very reasonable price the publishers ask for it. J. T. RANDALL.
HERCIK. 15 x 22 OberJEachenspannung in der Biologie und Mediain. By FERDINAND cm.; xii 220 pp. Dresden and Berlin: Steinkopff, 1934. Price: unbound, 14 M ; bound, 15 M. This small volume deals essentially with the changes in surface tension caused by the solution of materials mainly of biological processes. Great emphasis is laid upon the utility of the ring method for determining these changes, a view with which many investigators would in all probability not agree. The data of Du Noiiy are cited in extenso. These data on the surface tensions of dilute solutions present t h e
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