200 : Of the Arsenic 



form. This ore geneialiy looks externally of a 

 da^k-grey, and fometimes quite black ; yet, upon 

 breaking, it appears of a bright, metallic, leady 

 colour ^ but upon lying expofed for a while in the 

 air, is again overcaft with the fame blacknefs as 

 before. Externally it Teems like teftcceous cobald, 

 as if made up of fhelis laid one over the other ; yet, 

 internally, thefe run all into one another, without 

 further diltinction of layers. Some alio call it co- 

 bald and teftacecus cobald, efpeciaUy miners, who 

 call every thing cobald, that is either poifonous, 

 or with which they are unacquainted ; though the 

 more cautious and diftjnet appellation would be, 

 black po?fcn-cre, foflile fly -ft one, or even foffile black 

 arfenic: for, in its genuine mixtion, without any 

 other mineral adhering to, or interfperfed with it, 

 it- is not only entirely fugitive, not leaving the lead 

 fixed earth behind, but in the fire it exhibits alto- 

 gether the fame appearance as the fictitious fly- 

 itone from mijfpickel. 



It was formerly dug for at a certain Mifnian arfe- 

 »/V-work near Schwaitzenbzrg, and the Joachun- 

 flhal, in Bohemia, is remarkable for it ; and it is 

 faid to be no ftranger at johan-Georgen-Stadt and 

 Ehrenfriderfdorff in Mifnia, where the beautiful, 

 tranfparent, red geldijh ore breaks. The circum- 

 fiance, namely, that fuch redgoldijh ore affects, 

 or is affected by this poifonore, muft yield no de- 

 fpicable hints to diligent enquirers into nature •, 

 though I would be far from affirming th^ red- 

 goldijh ore to be produced from it : but here kt the 

 proper caution be me.de u'e of which a careful one 

 uiould ever keep in his eye, when, for avoiding 

 fallacious conciufions, he would judge of the on-' 

 gination of two forts of ores, lying near, or en- 

 t angled in each other. 



As 



