Copper and Silver of Kewenaw Point, Lake Superior. 91 
- The vein has no regular walls, but on the upper side of the 
lode there is a line of division between it and the trap, where no 
metal is found. On the lower side, the copper extends to the 
distance of ninety feet, but the limits in which I calculate the ore 
to be rich enough to work, give but eleven feet as the width. Its 
extent in length is yet unknown, but it has been seen interrupt- 
edly for the distance of about half a mile—there being only a few 
places where it was uncovered. 
Farther up Eagle River, at the distance of half a mile, a reg- 
ular vein of copper was discovered in a rock composed of crys- 
tallized feldspar and chlorite—the vein stone consisting of a mix- 
ture of green earth, quartz and calcareous spar. It is from two 
to three feet wide, is fully exposed on the river’s side for the 
distance of one hundred and ninety eight feet, and was seen in- 
terruptedly for a quarter of a mile. It runs N. by W., 8S. by E., 
and dips tothe E. 83°. This vein contains lumps of pure metal- 
lic copper, some of which weigh from a few ounces to halfa 
pound, and others are of an irregular form and as large as a man’s 
finger. Smaller pieces are thickly interspersed in the vein stone. 
On analysis this metal was found to be perfectly pure copper, 
without any trace of silver—a curious circumstance, considering 
its proximity to the silver vein above described. It will be 
wrought for copper in conjunction with the other mine. 
Analysis and Assay of the Eagle River Copper and Silver 
Ore.—In order to discover the real working value of an ore of 
this kind, it became necessary to make a selection of a fair aver- 
age lot of the ore, of a quality such as could be depended upon 
asa regular product of mining operations. I therefore blasted 
off specimens from the whole width of the vein, and rejecting 
the sheets and loose lumps of metal found in the crevices, took 
fifty pounds of the rock, containing a pretty uniform and fair mix- 
ture of the metals, for analysis. This was crushed at Henshaw, 
Ward & Co.’s mills, and sifted in coarse and fine sieves to sepa- 
rate the flattened plates of metal, which weighed 11 lbs. 4 ounces, 
and consisted of plates of copper and silver mixed with a little 
rock. On being carefully washed, the weight of metal was re- 
duced to 8 lbs. 13 ounces. This dissolved in pure nitric acid, 
and parted by chlorohydric (muriatic) acid and reduced, yielded 
662:8 grs. of metallic silver—equal to 252, lbs. per ton. The 
copper amounted to 5 lbs. 8$ ounces, or 1257 lbs. of copper per 
ton of coarse metal, as it comes from the washing table. 
