In the Pyrites; 205 



We fhall now confider the properties of arfenic, 

 or rather its ore-, (1.) In the earth. (2.) -Air. 

 60 Fire. 



(1.) Its bed in the earth we have already confi- 

 dered ; only this circumftance is to be added, in 

 which it differs from the fulpbur-pyrites ; viz. that 

 it always breaks near other ores j and only in rlflfures 

 and veins, never in nefts, as the fulphur- pyrites. 

 The ^bite-pyrites does not difTclve, crumble, vi- 

 triolife, or in the language of miners, become 

 weathered, as the yeiJowifh and yellow do, efpeti* 

 aily the firft ; for ( 1.) it contains no acid fait, as ful- 

 phurdoes, capable of exerting itfelf, and faltening 

 on the iron-earth to the deftruction of the whole 

 texture. (2.) Arfenic and iron, of which the white 

 pyrites confifts, are too clofely entangled, much 

 more fo than fulphur and iron. Whence might be 

 foonerfurmifed the weathering or diifolution of the 

 foffil ^black arfenic, ox fly -ft one, as being combined 

 neither with iron nor any thing elfe. Lajtly, the 

 arfenic in the -mer.tior.ed clays, alfo the pure, 



white gt 'cove- arfenic of Joachimftbal -, being the for- 

 mer {from the mentioned clays being at the fame 

 time vitriolic) a fulpbur-pyrites ; the vitriol., arifing 

 from the cm 1 ruction of the ore, carries alon^ 

 with it, by mean* ot the water, that faiall arfenical 

 portion mixed in therewith •, the latter has for its 

 ground the ; g black grey poifon-orc, not our 



arfenic pyrites, as not being found near it. 



(2.) !r. the a : r, the white fiy ite : maintains itfelf no 

 lefs conftant and unchangeable in its mixtion, in what 

 manner, for what time, or in what place foever it 

 be expofed. Nay, it needs mud, as it is rvutcnt, 

 arfenic is the grand, if not the only why the 



full 



