Platinum and the Metals of the Platinum Group.

WHAT promises to be the most complete and authoritative work on platinum and platinum deposits is about to be published in Geneva, Switzerland. The author, Louis Duparc, is professor of chemistry and petrology in the University of Geneva; the name of Marguerite N. Tikonovitch is announced as that of the associate author.' Professor Duparc has long been known as the writer of many papers on the great platinum deposits of the Ural region in Russia, of whicn he has made special study. He has also investigated personally the notable platinum deposits in other parts of the world, and he gives in the present work the ripe results of more than twenty years investigation of the sources of this rare metal. The first chapter will be devoted to the topography and geological aspects of the Ural region. This is followed by a chapter treating of the "mother rocks" of platinum, and by others on the petrography of the primary platiniferous centers, the dunites and peridotites. Then, in turn, are offered considerations on the pyroxenites and koswites, the rocks of the gabbro family and various vein rocks. The view is then extended to cover the metamorphosic rocks accompanying the eruptive platiniferous zone. Turning then to what more immediately concerns the metal itself, the constituent elements of native platinum are studied, and its state in the different primary deposits, as well as the probable genesis of these deposits. The writer now passes to the analysis and chemical 1 Louis Dupare and Marguerite N. Tikonovitch, "Platinum and Platinum Deposits," pub. by "ISoeiot Anonyme des Editions 'Sonor,' " 46 Rue du ,Stand, Geneva, Switzerland, 600 pp., 99 text ill, 90 stereotype pls., 11 in black and color, 8 of dredges, etc., atlas of Ural deposits, 4'. o n A pr il 15 , 2 01 7