TRANSLATOR’S PREFACE. Several motives have induced me to undertake the labor of translating this work: first, that no work of a kindred nature has appeared, since the able one of Professor Whitney on the Metal lic Wealth of the United States: next, the high personal respect I feel for Professor Von Cotta, and his kind encouragement to this undertaking: lastly, the desire of placing some of his valuable observations within the reach of students in my native country, who have not had the opportunity of hearing the Professor, or reading his works in German. I shall feel more than compensated for the time spent, should it at some future day induce the production of a work of a similar character on the various mining districts of this country; and, with a view to that end, lead to the close obser vation of the peculiarities of each mining-district. It has often been said, that the cause of the rapid progress of the moral and material development of this people has arisen from the personal character of the first settlers. Let us hope that the same intellectual energy may be applied to the scien tific observations of our mineral products. In Europe such ob servations have been the growth of centuries. Whilst we acknow ledge our debt for such patient labor, let us try in part to repay them by a careful study of our own resources. The mineral wealth, moreover, that awaits our gathering, is enormous. We must not forget, that economy in its collections