By submitting a small portion of the metal to the action of nitric acid, I obtained an imperfect solution. On repeating the experiment, and adding a little sulphuric acid, the action was more brisk, and a clear and apparently perfect solution effected. By standing, however, a pulpy, white precipitate appeared at the bottom of the glass. This was collected and submitted to the action of the blowpipe, on a basis of charcoal. The result gave a number of minute, metallic globules, possessing greater lustre, malleability, and ductility, than the original mass. I repeated the latter experiment, adding to the nitro-sulphuric solution muriate of soda. A more perfect precipitation of the white powder was effected; but the results with the blowpipe remained the same.
Geognostic Position.—It is a rolled mass. An opinion of the specific character of the rock may be dubious, from the smallness of the specimen. It appears to have been detached from a stratum of gneiss, and is essentially composed of quartz. The blackish color of some parts of this latter mineral would, at first glance, lead us to attribute this color to the presence of hornblende; but, on closer examination, it will be perceived to be owing to a dark-colored steatite, which, in certain parts of the rock, is well developed, soft, and easily cut. A little calcspar is intermingled with the steatite.
Locality.—I am indebted to the politeness of Lieut. Lewis S. Johnston, of the British Indian Department, at Malden (U. C.), for the opportunity of adding this specimen to the mineralogical cabinet of the Lyceum. This gentleman, as he informed me, obtained it from an Indian, who picked it up on the southeastern shores of Lake Huron, near Point aux Barques, in Michigan Territory. That part of Lake Huron was cursorily examined by me, in the year 1820, in the course of the expedition conducted by Gov. Cass, through the upper lakes, &c. I consider it remarkable, even in a region abounding in rolled rocks, for the great number and variety of granite, gneiss, hornblende, and trap boulders, scattered along the shores of the lake. The water here is generally shallow and dangerous to approach in vessels; these boulder stones sometimes extending and presenting themselves above water for a mile or more from land. But we could not satisfy ourselves by an examination necessarily partial, that either of the primitive species mentioned, existed there in any other condition than as rolled masses, or displacements of rock strata, contiguous, perhaps, but not observed. Dr. Bigsby has informed me, that he observed the gneiss in sitû, on the northwestern shores of this lake. The nearest rock in place, and that which in fact constitutes the abraded and caverned promontory of Point aux Barques, is gray sandstone.
The occurrence of this metal in the copper-bearing and other metalliferous rocks of this region, may be confidently affirmed.[ [273]
3. A General Summary of the Localities of Minerals observed in the Northwest in 1831 and 1832. By Henry R. Schoolcraft.
CLASS I. Bodies not metallic, containing an acid.
1. Calcareous spar. Keweena Point, Lake Superior. Imbedded in small globular masses, in the trap-rock; also forming veins in the same formation. Some of the masses break into rhombic forms, and possess a certain but not perfect degree of transparency; others are opaque, or discolored by the green carbonate of copper. Also in the trap-rock between Fond du Lac and Old Grand Portage, Lake Superior, in perfect, transparent rhombs, exhibiting the property of double refraction. Also, at the lead mines, in Iowa County, in the marly clay formation, often exhibiting imperfect prisms, variously truncated.
2. Calcareous tufa. Mouth of the River Brulé, of Lake Superior. In small, friable, broken masses, in the diluvial soil. Also, in the gorge below the Falls of St. Anthony. In detached, vesicular masses, amidst debris.
3. Compact carbonate of lime. In the calcareous cliffs of horizontal formation, commencing at the Falls of St. Anthony. Carboniferous.