m 



The proportion of silver mixed with the copper, at the Lake 

 Superior, and Pittsburgh and Isle Royal Company's mines, on 

 Eagle River, is of much greater value than the copper in the 

 same rock, and will be advantageously separated. 



He would refer to his Reports to those companies for details 

 concerning the value of their ores. A new vein has recently 

 been discovered by the Pittsburgh and Isle Royal Company, at 

 their mines, on the south-west branch of Eagle River, which has 

 furnished specimens of native silver of extraordinary richness, 

 some of which have been analyzed by Mr. A. A. Hayes. The 

 Lake Superior Company's mines are wide, and sufficiently rich 

 for profitable mining. [See his Reports to that company.] 



The Copper Falls Company have a remarkable vein of metallic 

 copper, which is from six to eighteen inches wide, and is charged 

 so fully with copper as to resist the drill. Its extent is not yet 

 known, but it was traced, for the distance of eighty feet, in a 

 course parallel with that already noticed as the general direction 

 of the veins in the trap rocks. He had recently learned that 

 very large sheets of metallic copper had been discovered in 

 working this vein, and that the amygdaloidal wall rock was quite 

 rich in copper. A little metallic silver has also been found as- 

 sociated with the copper in the vein. The Boston Copper Com- 

 pany has opened a very remarkable vein of copper at Agate 

 Harbor. It is a regular vein of crystalline calcareous spar, tra- 

 versing the conglomerate in a north and south direction, and is 

 five inches wide on the top of the cliff, on the lake shore, and one 

 foot wide near its base, twenty feet lower down. In this vein, he 

 found crystals of metallic copper quite abundantly, and some 

 very large lumps and crystalline masses. He obtained one mass 

 weighing forty pounds, which was covered with crystals of pure 

 copper and particles of silver. Another mass had been sent him 

 by the miners, which weighed more than one hundred pounds, 

 and another had been sent to the trustees of the company which 

 weighs five hundred and sixty-four pounds. The prevalent 

 forms of the crystals are the regular octahedron and the rhombic 

 dodecahedron with the edges replaced by single planes ; but 

 other and more complicated forms also occur. 



It is obvious, both from the crystalline forms and the mode of 

 occurrence of this copper, that it was deposited from a state of 



