266 Natural Hiftory of Mercury. [Book Vt. 



earths or clays of different colours, from Which it may 

 be feparated either by trituration or lotion, the fmaller 

 globules coakfcirtg by mutual contact into larger 3 or 

 by dii I illation. 



More mercury is found in the ftate of cinnabar 

 than in its metallic form. This ore confifts of mer- 

 cury and fulphur combined together in different pro- 

 portions. Cinnabar is fometimes found in the form 

 of a brilliant red powder, and is then called native 

 Vermilion, fometimes in an indurated ftate, and though 

 generally red, has been fometimes obferved of a yel- 

 lowilh or blackifh caft. It is moftly opake, but fome 

 Specimens are as tranfparent as a ruby. 



Mercury is too volatile to admit of the fulphur being 

 Separated from it by roafting ; thefe fubftances are 

 both fo volatile that they would rife together. In or- 

 der to feparate mercury from its ore it is neceffary to 

 add quick lime, or iron filings, unlefs fome fubftances 

 of a fimilar nature happen to be naturally mixed with 

 it; the mafs is then fubmitted to diftillation, and the 

 calcareous earth, or iron filings, by fuperior attraction, 

 detain the fulphur, while the mercury comes over in 

 the ftate of vapour, and is condenfed in the receiver. 

 Different cinnabars yield from three parts to feven 

 parts in eight of their weight of mercury. Mercury 

 has fometimes been found united with the muriatic 

 and vitriolic acids, and with the ores of fome other 

 metals. It is thought to be not abundant in nature -, 

 but this opinion may be partly owing to its volatility, 

 which may prevent it from being difcovered in many 

 minerals that may contain it. Moft of the mercury in 

 commerce is afforded by the mines of Idria in the 

 Auftrian dominions, Almaden in Spain, and Guanca- 

 velica in Peru. 



The vitriolic acid does not act on mercury unlefs 



concentrated 



