There are indications that this mineral pervades the rocks and soils, in a radius of one hundred and fifty miles or more, south and west of this central point. It has been discovered at the sources of the Menominee, Chippewa, Montreal, and St. Croix, and even at more distant points. At St. Peter's, in digging down for the purpose of quarrying the rock, about eighteen inches depth of dark alluvium was passed; then a deposit of diluvial soil, with large fragments of limestone, greenstone, quartz rock, &c., about six feet; and, lastly, one foot of small pebbles, &c., constituting the copper diluvium. No large mass was found; nor any veins in the rock. 2. LEAD. The only ore of lead known to exist within the limits to which these remarks are confined, is the sulphuret. In the year 1780, Peosta, a woman of the Misquakee, or Fox tribe of Indians, discovered a lead mine upon the west banks of the Mississippi, at the computed distance of twenty-five leagues below Prairie du Chien, which the Indians, in 1788, gave Julian Dubuque a right to work. This permission was partially confirmed by the Baron de Carondelet, Governor of Louisiana, in 1796. No patent was, however, issued; but Dubuque continued to prosecute the mining business to the period of his death, which happened in 1810, when the mines were again claimed by the original proprietors. The ore is the common sulphuret of lead, or galena, which Dubuque stated to have yielded him seventy-five per cent. in smelting in the large way. He usually made from 20,000 to 40,000 pounds per annum. I made a cursory visit to these mines, and found them worked by the Fox Indians, but in a very imperfect manner. They cover a considerable area, commencing at the mouth of the Makokketa River, sixty miles below Prairie du Chien. Traces of the ore are found, also, on the east bank of the Mississippi at several points. It occurs disseminated in a reddish loam, resting upon limestone rock, and is sometimes seen in small veins pervading the rock; but it has been chiefly explored in diluvial soil. It generally occurs in beds having little width, and runs in a direct course towards the cardinal points. They are sometimes traced into a crevice of the rock. At this stage of the pursuit, most of the diggings have been abandoned. Little spar or crystalline matrix is found in connection with the ore. It is generally enveloped by a reddish, compact earth, or marly clay. Occasionally, masses of calcareous spar occur; less frequently, sulphate of barytes, green iron earth, and ochrey brown oxide of iron. I did not observe any masses of radiated quartz, which form so conspicuous a trait in the surface of the metalliferous diluvion of the mining district of Missouri.