from the Pyrites. 281 



In fhort, all the abovementioned are certainly 

 vitriols, and vitriolic mixtures, though no one of 

 thefe titles is properly expreffive of their nature, 

 all of them meaning only fomething incidental. 

 Chalcitis, in its proper fignification, which yet is 

 not the common, fhould denote a copper-ore, or 

 copper-ilone -, but being now defcribed from its 

 earth or (tone, and its red colour, it is, infomuch, 

 referable to the incidental defcription of the others. 



As to fory and melanteria, I find fuch pyrity, vi~ 

 triolic, dark- grey foiver, not only in the grooves, 

 but alfo at the day, after having lain there expofed 

 for fome time. Hither alfo may be referred the 

 vitriolic -fory '-earths from other places ; though un- 

 der this appellation, Galen only mentions a firm 

 floney matter ; as M. Berger *, in his treatife on 

 the Carlsbad waters, mentions fuch a fort ktn at 

 Siena in Italy (fo alfo does Matthiolus, in his 

 commentary on Diofcorides f ) and compares it 

 with the vitriol-earth, near Schmiedeberg in Sax- 

 ony : and as to mify, we find it often repeated, 

 that fory changes fo chalcitis, chalcitis to mify, not 

 only by Caneparius, but alfo by others; by chal- 

 citis not meaning a crude, red, vitriolic mineral, 

 but the vitriolic efrlorefcence itfelf. 'Tis true, a 

 black pyrity mineral gives forth a white vitriolic 

 eflorefcence, which, at length, turns yellow : nay, 

 a vitriol, whether naturally green or blue, does, 

 by means of a warm air, or a foft fire, not only 

 crumble to a white powder, but alfo this powder*, 

 both fuperficially, and at lad throughout, turns 

 *of a yellow caft; 'till at length, by heightening 

 nre, it is all changed to a red powder. 



Yet 



f Btrgeii Commentat. de Therm. Carol, p. 197. 

 t L . v. c, 74. 



