PREFACE 



This work is based upon a scries of lectures which the author 

 has been compiling for more than twenty years. It treat- only 

 of the metallic ores in addition to the chapters on the origin of ore 

 deposits. The metals are arranged, with the exception of the 

 precious and rare metals, in the order of their group separation, 

 and the chapters comprise the metals of the different groups. 

 A final chapter gives the economic or statistical treatment . 



It has seemed wise to the author to omit the references which 

 are given to students for library or laboratory work, as these are 

 l>est worked out by each teacher to meet his own views and the 

 needs of his individual pupils. The author has in preparation 

 also a companion book covering the non-metallics. 



The author wishes to express his great indebtedness to Prof. 

 T. C. Hopkins, Syracuse University, who has read both the 

 manuscript and the galley proofs and offered many timely sug- 

 gestions in the preparation of the book; to Prof. W. J. Miller, 

 Hamilton College, who has read the manuscript entire; to the 

 many professors of other universities who have read various 

 chapters of the manuscript and heartily cooperated with the 

 author in this work; to Prof. Hemrich Ries, Cornell University, 

 not only for his "Economic Geology," but also for the use of 

 many of his photographs to which credit is given in the text; to 

 Thomas and MacAlister, authors of "The Geology of Ore 

 Deposits"; to F. W. Clarke, Chief Chemist of the U. S. Geological 

 Survey, "The Data of Geochemistry"; to Prof. J. F. Kemp, 

 Columbia University, "Ore Deposits of the United States and 

 Canada"; to Prof. J. C. Branner, Leland Stanford University, 

 "Syllabus of Economic Geology"; to the authors of the Mineral 

 Industry, its Statistics, Technology and Trade; to the compilers 

 of the various volumes of the Mineral Resources; to the authors 

 of all geological publications whose works have been consulted 

 and embodied in part in this volume; to the Macmillan Company 

 for their courtesy in loaning many cuts; to the Engineering and 

 Mining Journal and the Canadian Geological Survey for the use 

 of illustrations; and to the authors of all other cuts save the 

 original drawings from whatsoever source they may have been 

 derived. 



CHARLES H. RICHARDSON. 



SYRACUSE UNIVERSITY, 

 November, 1913. 



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