METALLURGY. 



them; and thence he concludes that they were not calamine stones: 

 for every stone, says he, which being mixed with charcoal, and 

 exposed in close vessels to the action of a violent fire, does not 

 yield zinc, or which in an open fire does not with copper and 

 charcoal produce brass, ought not to be considered as a calamine 

 stone*. Ilourkel had long before given a similar definition of zinc, 

 when ho observed that it was the only substance in nature which 

 had the quality of giving copper a yellow colourt. 



Pott wrote a dissertation on zinc in 1741, in which he enters 

 into the history of the discovery of this semi-metal. Bergman has 

 availed himself of all that Pott knew on that subject, and has 

 added several things of his own : I cannot compress the matter 

 into a less compass than he has done. " The semi. metal which at 

 present is called zinc, was not known so much as i>y name to the 

 ancient Greeks and Arabians. The name which it bears at pre. 

 sent first occurs in Theophrastus Paracelsus J, but no one as yet has 

 been able to discover the origin of this appellation. A. G. Agri- 

 cola calls it contrefeyn ; Boyle, speltrum|| : by others it is deno- 

 minated spiauter, and Indian tinH. Albertus Magnus, more pro. 

 perly cal ed Bolsfadt, who died in 1280**, is the first who makes 

 express mention of this semi-metal. He calls it golden marcasite, 

 asserts that it approaches to a metallic nature, and relates that it 

 is inflammable. However, as zinc is white, the name of golden 

 marcasite is not very proper ; it would therefore appear probable 

 that it derives that name from the golden colour which it commu- 

 nicates to copper, had not Albertus expressly said, that copper 

 united with golden marcasite becomes white ; but he has probably 

 either misunderstood or misrepresented what he had heard related 

 by others, it may also happen that zinc was formerly thought to 

 contain gold. J. Matthesius+t, in 1562, mentioned a white and a 

 red zinc ; but the yellowness and redness are only to be under- 

 stood of the ores. llollandus, Basil Valentine, Aldrovandus, 

 Caesius, Caesalpinus, Fallopius, and Scroeder, observe a profound 

 silence on that head. JJ The eastern Indians have long since been 

 in possession of the method of extracting pure zinc from the ore; 



Opog. de Mar*, vol. I. p. 94. t Pyrito. French Trans, p. ?48. 



| In Operibus passim. ^ De Re mctallica. 



8 PoDderib. Flammae. f Taeda Trifid.-x Cl\vraica 



In Libro Mincralium. t Sarcptn. 



} Poll on Zinc. 



