Account of the discovery of silver in herland copper mine

This ore was found in the Herland mine, about six miles from St. Michael’s Mount in Cornwall. It consists chiefly of lodes of eopper, of which several run nearly in a parallel direction from east to west. The peculiarity here is, that there are several cross courses which run north and south, the greatest part of which contain no metal; these meeting with the lodes of copper ore, interrupt their continuity, or, as is expressed by the miners, heave them out of their direction, so that at the place of intersection the copper lodes seem to have been forced aside eighteen or twenty inches. One of these cross courses has of late been discovered to yield silver in no inconsiderable quantity; but with this particular circumstance, that at and near the place of intersection the ores both of silver and copper are much less productive than at some distance from it. The silver ore consists of a mixture of galena, native bismuth, gray cobalt, vitreous silver, and native silver chiefly in a capillary form.