Silver and its ores are not of frequent or extensive occurrence in the United States. Doctor Dana states the curious fact, that a mass three or four inches in diameter, composed principally of native silver in filaments, was found on the top of a wall near Portsmouth, New Hampshire; the surrounding hills are chiefly greenstone. Mercury, which has been found native in Kentucky, occurs more plentifully as a sulphuret in Ohio and the Michigan territory, more particularly on the shores of lakes Michigan, Huron, St. Clair, Detroit river, and Lake Erie, to the mouth of Vermilion river. It occurs in the soil in the form of a black and red sand, but is usually more abundant in banks of fine ferruginous clay. Near the mouth of Vermilion river, it is in the form of a very fine powder, or in grains and small masses, disseminated in clay. It yields by distillation about sixty per cent. of mercury. Copper, in various forms, is found in the United States, but the ores do not appear to be brought into use. It is not found on the shores of Lake Superior so abundantly as was anticipated; but many specimens of copper ore have been found at different points in the Mississippi valley. Specimens of pure and malleable copper have been obtained; one of which, said to have been found in Illinois, weighed three pounds. Iron ores are abundant in the United States. Those hitherto worked are chiefly the magnetic oxide, brown hematite, and the argillaceous oxide, particularly bog ore. The more important ores are the following, viz.: in New Hampshire, the magnetic oxide; in Vermont, brown hematite and bog ore; in Massachusetts, bog ore; in Rhode Island, brown hematite; in Connecticut, brown hematite and bog ore; in New York, the magnetic, specular, and argillaceous oxides; in New Jersey, the magnetic and argillaceous oxides; in Pennsylvania, and the states south and west, the magnetic oxide, brown hematite, and the argillaceous oxide. To these may now be added the carbonate of iron, which has recently been successfully smelted, and which produces iron having the carbonaceous impregnation of steel, whence it has been called steel ore. In New York, New Jersey and Pennsylvania, the ore is found in abundance, and of a quality not exceeded in Sweden. The Connecticut and Virginia iron is highly esteemed.