[A]Professor J. W. GREGORY, F.G.S., Professor of Geology, University of Glasgow, formerly Director of Geological Survey, Victoria, Australia. Sir ROBERT HADFIELD, Bart., F.R.S., Past-President Iron and Steel Institute. Captain A. L. ELSWORTHY, Intelligence Department, War Office (nominated by the War Office). W. W. MOYERS, Esq. (Messrs. A. Watson & Co.), Liverpool. R. ALLEN, Esq., M.A., B.Sc., Imperial Institute (_Secretary_). Footnote A: Members of Editorial Sub-Committee MINERAL SECTION Principal Members of Staff _Superintendent_ R. ALLEN, M.A. (Cantab.), B.Sc. (Lond.), M.Inst.M.M. _Assistant Superintendent_ S. J. JOHNSTONE, B.Sc. (Lond.), A.I.C. _Senior Assistants_ G. M. DAVIES, M.Sc. (Lond.), F.G.S. W. O. R. WYNN, A.I.C. _Assistants_ S. BANN. F. H. BELL. H. BENNETT, B.Sc. (Lond.). A. T. FAIRCLOTH. R. C. GROVES, M.Sc. (Birm.). E. HALSE, A.R.S.M., M.Inst.M.M. PREFACE The Mineral Resources Committee of the Imperial Institute has arranged for the issue of this series of Monographs on Mineral Resources in amplification and extension of those which have appeared in the _Bulletin of the Imperial Institute_ during the past fifteen years. The Monographs are prepared either by members of the Scientific and Technical Staff of the Imperial Institute, or by external contributors, to whom have been available the statistical and other special information relating to mineral resources collected and arranged at the Imperial Institute. The object of these Monographs is to give a general account of the occurrences and commercial utilisation of the more important minerals, particularly in the British Empire. No attempt has been made to give details of mining or metallurgical processes. HARCOURT, _Chairman Mineral Resources Committee_. IMPERIAL INSTITUTE, LONDON, S.W.7. _July 1920._ CONTENTS CHAPTER I PAGE =THE PLATINUM METALS: THEIR OCCURRENCES, CHARACTERS AND USES. WORLD’S OUTPUT= 1 CHAPTER II =SOURCES OF SUPPLY OF PLATINUM METALS=