252 METALS. 82. Argentum. 



erseniacum* With a metallic fplendour, eafily melting and emitting 

 arfenical vapours. 



Werner Samml, ph-jjf. riatur, i.^. 5/. 4. ^.454, 

 Arfenicated lilver >chmeijier miner ^ 2. />. 42. 

 Arlenicated native filver. Kir-ix: an mineral. 2. p. III. 

 Aif^nical filver. ^homfon chem. ^. p. 25. 



Found in the mines near AndreaJLurg in Hercynicty fometimes 0/ 

 a Heel-white colour and luftre and containine: a little iron, 

 ibmetimes pale ochre-yellow; it- hardncfs is ofren coi.fider- 

 able, and then it is fibrous internally, fometimes it is fo foil 

 as to be eafily cut with a knife and in cuived foliations: 

 commonly found in round irregular lumps or cr) fiallized in 

 6-fided prifms or pyramids: contains filver 12,75. ^^^^^ 

 44,25, arfenic 35,00. andmpny 4,00. Klaprctb. 



m^lyhdtsna' With a metallic fplendour, in thin flexible plates. 

 turn, Freherv(yv. afi- petrop 3. p. 267. 



Molybdenic filver ore. Schmei/Jer mineral. 2. /, 51. 



Found TitZT Deutchpilfen in Hnvgaryy in thin broad fhining plate% 

 placed one over the other, fometimes nearly an inch in thick- 

 nefs, in grey alumina: it gives a grey rtreak to paper, and 

 has fomething the refemblance of common Molybdjcnum : 

 it has fometimes a little iron mixed with it, and uiually yields 

 23 ounces of filver in a hundred weight. 



*viireum. Of a dark blueifh-grey colour, eafily melting and emitting 

 during combui'tion fulphurous flames and vapouis, 

 opake, very ponderous, foft, tenacious. 



Argentum mineralifat. ^y/t.nati k\\. 3. /. 148. ;;. 3. 

 Argent, fulph. mineralis. WalL fyji. 2. /. 329. ». 2. 

 Sulphurated filver ore. Kirtuan mineral. 2, p. 11^. 

 Vitreous filver. Sch/nei/ser miner. 2. /. 44. 

 Sulphuret of filver. Thomfon chem. 4, /». 26. 



Found in the mines o{ Siberia^ Nor^way, Saxony^ Bohemia, Hun- 

 garyy Spain, and Jimenca, generally fuperficial and running 

 like veins through other foflils : colour deep lead-grey, grey- 

 ifh-black, or fteel-blue, with very little metallic luilre, and 

 * fometimes variegated on the furface : its appearance is rarely 



maflive, but mott commonly in thin plates, granular, capil- 

 lary, arborefcent, or cryftallized in cubes or in double 4 or 

 6-fided pyramids: internally it has rnore of a metallic luftre ; 

 is foft enough to bear impreffions like lead, and melts eafily 

 into a vitreous mafs. It is one of the richeft ores of fiiver, 

 containing ufually 85 percent, of pure filver; fpecific gravity 

 from 6,909. to 7,215, 



