252 APPENDIX. 



Finally, the Wisconsin copper ore derives additional value 

 in consequence of being found in the vicinity of, and often in 

 the same mine as, productive veins of 



ZINC ORE. 



" This ore, found both in Iowa and Wisconsin, usually 

 occurs in the fissures, along with the lead. It is chiefly the 

 electric calamine — the carbonate of zinc of the mineralogist. 

 Though a solid ore, it has an ochreous, earthy aspect, often 

 resembling the cellular substance of the bone : hence it is 

 familiarly known among the miners by the name of ' dry 

 bones.' 



*' Notwithstanding its intrinsic value, which will before 

 very long be duly appreciated, it is at present an object of 

 especial aversion to the miner of Iowa and Wisconsin. It 

 frequently happens, in both Territories, that the load ore in a 

 fissure gradually diminishes, and eventually is entirely re- 

 placed by this zinc ore ; or, as the disappointed workman, 

 sometimes with a hearty curse, not very scientifically ex- 

 presses it, * the dry bone eats out the mineral.' 



" At some of the diggings, large quantities of this carbo- 

 nate of zinc can be procured. Thousands of tons are now 

 lying in various locations on the surface, rejected as a worth- 

 less drug — indeed, as a nuisance. It is known to but a few 

 of the miners as a zinc ore at all. An analysis of this ore 

 proves it to be a true carbonate of zinc, containing forty-five 

 per cent, of the pure metal. 



" Sulphuret of zinc (sometimes called blende, and, by the 

 Enghsh miner, ' black-jack') is also abundant in the Wiscon- 

 sin mines. It contains from fifty-five to sixty-five per cent, 

 of zinc, but is more difficult of reduction than the calamine. 



" Sheet zinc is becoming an article of considerable de- 



