[Illustration: PROSPECTING THE GROUND.] [Illustration] UNDERGROUND TREASURES: HOW AND WHERE TO FIND THEM. A KEY FOR THE READY DETERMINATION OF ALL THE USEFUL MINERALS WITHIN THE UNITED STATES. BY JAMES ORTON, A.M., _Late Professor of Natural History in Vassar College, N. Y.; Cor. Mem. of the Academy of Natural Sciences, Philadelphia, and of the Lyceum of Natural History, New York; Author of “The Andes and the Amazon,” etc._ A NEW EDITION WITH ADDITIONS. ILLUSTRATED. PHILADELPHIA: HENRY CAREY BAIRD & CO., INDUSTRIAL PUBLISHERS, BOOKSELLERS AND IMPORTERS, 810 WALNUT STREET. 1881. Entered according to Act of Congress, in the year 1872, by WORTHINGTON, DUSTIN & CO., In the Office of the Librarian of Congress, at Washington, D. C. Copyright: HENRY CAREY BAIRD & CO. 1881. _Table of Contents._ CHAPTER I. .....PAGE. INTRODUCTION.--Money in the Rocks--The Underground Wealth of our Country--Valuable Minerals Disguised--How Great Fortunes are Missed--Number of Minerals in the United States--Object of this Work and How to Use it--The Best Mineral Regions.....9 CHAPTER II. DIRECTIONS FOR DETERMINING SPECIMENS BY THE KEY.--How to Test Minerals with the Simplest Means--Prospecting with a Jack-knife and Common Sense--Use of the Key--How to Tell Pyrites from Gold, and Quartz from Diamond--All the Useful Minerals Grouped According to Hardness and Color.....15 CHAPTER III.