lxvi Proceedings of the Asiatic Society. 



munitions of these mere surface specimens, for they may create an idea that a vein 

 is worthless which is, on the contrary, a rich one at 50 or 100 feet deep. The best 

 mines in many parts of the world are capped by poor ores, and sometimes of a dif- 

 ferent kind, and those almost worthless. The capping of copper by the common 

 Blende or "Black Jack" is a familiar instance, and lias even grown into a semi- 

 proverbial saying in Cornwall, where the miners think it a favourable indication 

 when sinking a shaft for copper, to find plenty of Blende (Sulphuret of Zinc) 

 M for," they say, " Black Jack rides a proud Horse." 



For all presentations and communications the thanks of the Society 

 were accorded. 



