Head winds continuing, we were farther detained at this spot the following day. While thus detained, an Ontonagon Indian brought in a mass of native copper, from the banks of this river, weighing eight or nine pounds. This mass was of a flattened, orbicular shape, and its surface coated with a green oxide. At a subsequent part of my acquaintance with this river, another mass of native copper (still deposited in my cabinet) was brought to me, from the east fork of the river, which weighed from forty to fifty pounds. This mass, of a columnar shape, originally embraced a piece of stone which the Indian finding it had detached. It was also coated with a dark green oxide of copper. Both of these masses appeared to have been volcanic. Neither of them had the slightest traces of gangue, or vein-matter, nor of attrition in being removed from the parent beds. The following sketches depict the shapes of these masses. [Illustration: Fig. 2.] [Illustration: Fig. 3.] With respect to the general question of the mineral character of this part of the country, and the probable value of its mineral and metallic deposits to the public domain, the entire class of facts, from which a judgment must be formed, are favorable.[53] Salts and oxides of copper are not only seen in various places in its stratification, but these indications of mineral wealth in this article are confirmed, by the subsequent discovery of masses of native copper, along the shore, and imbedded in its traps and amygdaloids. In addition to the opportunities of observation furnished by this expedition, subsequent public duties led me to perform seven separate trips along its shores, and each of these but served to accumulate the evidences of its extraordinary mineral wealth. Indications of the sulphurets, arseniates, and other ores of this metal are found in the older class of horizontal rocks; but it is to the trap-rocks alone that we must look for the veins of native metal. Some of these masses contain silver, in a state of combination. Traces of this metal, chiefly in the boulder form, are found in the metalliferous horizontal strata. Nor is there wanting evidence, that there are localities of virgin copper, which do not promise a considerable percentage of the metal. A mass of steatite, imbedding a heavy mass of pure native silver, which had been probably carried from the northwest, with the drift stratum, was found cast out quite into the Huron basin; and this rock, in its intimate associations with the serpentine formation of Lake Superior, should be closely scrutinized. There is also a formation of slate and quartz in the primitive district, which is entitled to particular attention. [53] _Vide_ Reports in the Appendix: 1. Report on the Copper Mines of Lake Superior, November 6, 1820. 2. Report on the Value of the Existing Evidences of Mineral Wealth in the Basin of Lake Superior to the Public Domain, October 1, 1822.