METALS. 93. Arfenicum. 301 



albicans. Of a fteel- white colour and luftre, hard, emitting white 

 arfenical vapours before the blowpipe but no fulphur 

 flame or vapour. 



Syli. nat xii. 3 ^. m8. /t.6, 7* 



If'^all. fyH muter al. 2. p, 165. «. 6, 7,8, 



Miflpickel. Ju(i. mtnfraL \^\, 



Arfenical pyrites, Marc^fite. Kir'-wanminer, 2. P- 256* 



Found in Comiva/I, near Dublin in Ireland, Bohemia, Silefta^ 

 Saxony^ Germany^ &c, generally difperfed among tin ores in 

 granulations, or cryftallized in 4-iidcd double pyramids or 

 4rrided obliquangled ptifms: colour fometimcs filvery, grey 

 or yellowini or irideicently variegated when urnilhed ; tex- 

 ture compaft, fomf'times a little fplintery, ^vith the furfacc 

 marked with decuflare grooves or black ramifications: cffer- 

 vefces with nitric acid without heat, and g'ves an arfeoicai 

 {mell when rubbed : it confifts of arlenic alloyed with a con- 

 fiderable quantity of iron, but little or no fulphur 1 fpeciiic 

 gravity from 5,75 3, to 6,5 2 2» 



argentifg" Gf a filvery luflre and very fine granular texture, emitting 

 rum. arfenical vapours before the blowpipe, and when fufed 



with lead leaving a filver bead. 



Argentum arfen'tcale. Syft. nat. xii. 3. p. 150. ». j, 

 Argentum arfenico min. VVall.fxft. 2. p. 340. n, 10. 

 Argentiferous arfenical pyrites. Ktrwan miner, 2. /. 257, 



Found in the mines of Saxonyy Bobemia^ Germany-) and Spain, 

 maflive, difleminated or acicular : colour nearly that of the 

 laft, but brighter and more permanent : it burns with a 

 white flame, and leaves a reddifh refiduum : by folution in 

 nitro-muriatic acid the filver will be precipitated ; it coniifts. 

 of arfenic, fulphur, iron, and from i to 10 or 12 f.x cent, 

 . 9f filver: fpecific gravity 4,087, 



