PEEFACE. The literature of metalliferous deposits, in the English language, is by no means inconsiderable. Numerous valuable disquisitions have at different times been published either as separate works or as communications to scientific journals, but the only general and systematic treatise on the subject which has appeared in English is a translation of Yon Cotta’s Lehre von den Erzlagerstatten, by Mr. Frederick Prime, published at New York in 1870. Since that date much valuable information upon this subject has been accumulated, and the investigations of Daubrtie, Daintree, Sandberger, and others have within the last few years thrown much additional light upon the genesis of metalliferous deposits. The present work, which includes the results of the most important recent investigations, is divided into two parts. In the first, ore deposits in general are described and classified, while, in the second, examples are given from the principal mining regions of the old and the new world. In this portion of the work many remarkable metalliferous deposits of both ancient and recent formation are described, while, as a means of forming a standard of their comparative importance, copious statistics of production are furnished. Wherever exact information on this subject has been available, tabulated statistics of the yield of the principal ore-producing countries have been supplied. This appears to be the only way of accurately expressing the relative importance of different metalliferous regions, and care has been taken to collect information from trustworthy sources only.