So The feveral SPECIES 



ore, whatever other accompanying parts there 

 may be in it. Sulphur is obferved to reduce the 

 white metals, and the femimetals, as filver, lead, 

 regulus of antimony, to black, or black-grey bo- 

 dies \ namely, to a glaffy ore, a lead-glitter and an 

 antimony ; with mercury alone changing to a 

 beautiful red. The red metals, as iron and cop- 

 per, it turns to a yellowilh and yellow mafs, which 

 is our pyrites. Arfenic leaves white what natu- 

 rally is fo, and blanches or whitens what is not 

 fo. Tin it exhibits in its native white character, 

 as appears from the tin-ftone. Iron it brightens, 

 as we obferve in Mifspickel, whofe native earth is 

 an iron. Copper, tho' naturally red, it thoroughly 

 tinges with its own livery, as fufficiently appears 

 from highly arfenical copper-ores. Silver it changes 

 red, a remarkable inftance of which we have 

 in the red-goldijb ores, For producing the yellow, 

 brown and black calls in fome tin Hones, fome 

 fulphur muft accompany the arfenic, to account 

 for an appearance fo oppofite to that of tin and 

 arfenic. To avoid prolixity, I fhall only hint, 

 that arfenic and filver, fulphur and quickfilver, 

 alfo fulphur and arfenic, do together exhibit co- 

 lours extraordinary red. In lead glitter ', glajfy ore, 

 antimony, and red-goldijh ore, the proximate caufe 

 of their colours lies in none of the parts whereof 

 thefe bodies confift, but is firft produced by an in- 

 timate action and reaction of thefe parts among 

 themfelves. In the others, and in many genuine 

 ores, we obferve the parts introduced bringing 

 along with them their proper colour ; particularly 

 in the pyrites, where the fulphur lofes not its yellow 

 character ; and the iron pyrites turning only a 

 little pale from the greynefs of the iron -, in copper- 

 pyrites, on the contrary, the colour being heigh- 

 tened, from the common experiment of a red 

 always heightening a yellow ; arfenic is the ma- 



nifeft 



