18 WRITINGS OF JAMES SMITHSON. 



A CHEMICAL ANALYSIS OF SOME CALAMINES. 



From the Philosophical Transactions of the Royal Society of London, 

 Vol. XCIir, page 12.— Eead Novemher, 18, 1802. 



Notwithstanding the experiments of Bergman and others, 

 on those ores of zinc which are called calamine, much uncer- 

 tainty still subsisted on the subject of them. Their consti- 

 tution was far from decided, nor was it even determined 

 whether all calamines were of the same species, or whether 

 there were several kinds of them. 



The Abbe IIauy, so justly celebrated for his great knowl- 

 edge in crystallography and mineralogy, has adhered, in 

 his late work,* to the opinions he had before advanced,! 

 that calamines were all of one species, and contained no 

 carbonic acid, being a simple calx of zinc, attributing the 

 eftbrvescence which he found some of them to produce with 

 acids, to an accidental admixture of carbonate of lime. 



The following experiments were made to obtain a more 

 certain knowledge of these ores ; and their results will 

 show the necessity there was for their farther investigation, 

 and how wide from the truth have been the opinions 

 adopted concerning them. 



Calamine from Bleyberg. 



a. The specimen which furnished the subject of this 

 article, was said by the German of whom it was purchased, 

 to have come from the mines of Bleyberg in Carinthia. 



It was in the form of a sheet stalactite, spread over small 

 fragments of limestone. It was not however at all crys- 

 talline, but of the dull earthy appearance of chalk, though, 

 on comparison, of a finer grain and closer texture. 



It was quite white, perfectly opaque, and adhered to the 



* Traite de Mineralogie, Tome IV. f Journal dea Min^s. 



