...components (arsenic, antimony, etc.) prevent it use as a source of copper in this country, where the general purity of our ores has established such a high standard...Vermont. This slight disadvantage is, however, far outweighed by their contents in silver, which partly owes its presence to this same arsenical mineral....

...greater or less extent by silver, this is seldom regarded in the United States as an ore of copper. standard for this metal. Only the most favorable circumstances,...metallurgical, and commercial, would render the working of uon-argentiferons fahlores at all practicable. This mineral occurs in small quantities in certain of...

...quantity. The silver-bearing varieties are mined not so much for the copper as for the silver content. Only the most favorable circumstances — mineralogical,...working of non-argentiferous fahlores at all practicable (Peters). The improved methods of recent years make a modification of this statement necessary ; for...

...quantity. The silver-bearing varieties are mined not so much for the copper as for the silver content. Only the most favorable circumstances — mineralogical,...— would render the working of non-argentiferous fall lores at all practicable (Peters). The improved methods of recent years make a modification of...