(1) PROF. SCHENCK'S course of lectures, delivered to an audience of technical men at Aachen, was first published in 1909, and at once proved of great service to teachers of metallurgy and to students desirous of acquiring an insight into the scientific principles underlying metallurgical processes. At the same time, it directed the attention of physical chemists to the large mass of intrinsically interesting material for the study of chemical reactions and equilibria which is available from metallurgical sources. The subjects of the lectures were:—The properties of metals; metallic solutions and alloys; carbides, oxides, sulphides, and mattes; the processes of oxidation and reduction; blast-furnace reactions; and the reactions of sulphides. Of these the subject of the constitution and structure of alloys has been treated by many writers, and text-books of metallography are numerous, but the kindred studies of mattes and slags, and of roasting and smelting reactions, have received far less attention. There is, therefore, room for such a work, and a translation is to be welcomed. (1) The Physical Chemistry of the Metals. By Prof. R. Schenck. Translated and annotated by R. S. Dean. Pp. viii + 239. (New York: J. Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1920.) 22s. 6d.net. (2) Electric Furnaces in the Iron and Steel Industry. By W. Rodenhauser J. Schoenawa C. H. Vom Baur. Translated from the original by the latter, and now completely rewritten. Third edition, revised. Pp. xxi + 460. (New York: J. Wiley and Sons, Inc.; London: Chapman and Hall, Ltd., 1920.) 24s. net.