METALS. 93. Arfenkruml 299 



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Toand in Great -Britain^ various parts of Germany, Nor^vay, 

 Saxony, Sec, accompanying fpir, barytes or feMfpar, maffive, 

 rarely difl'eminated, ofcen compofed of hemirpherical layers, 

 corroded, branched, perforated, botryoidal, or ilalaclilical ; 

 colour lead -grey, but its furface faon tarnifhing and becom- 

 ing black by expofure to the air: ftreak bluifh-grey, powder 

 dull and blackifli: fometimes a little fonorous when ftruck 

 againll a hard body, and fo foft as to be eafily ciit with a 

 knife : before the blowpipe it immediately emits a white 

 fmoke, difFuling its peculiar and highly poifonous vapours to 

 a great diflance, burning with a blue flame and gradually 

 vanifhing, depofitinga white oxyde in the form of a powder: 

 fpeciiic gravity 5,670. to 5,729: it is always alloyed with 

 i>>me iron, and often contains fome cobalt, bifmuth, fiiver, 

 and fometimes a little gold. 



calciforme. White, folubic in 80 times its weight of veater. 

 Arfenic. naiiv, album. Wall.fyit 2. p. 160. n. i. 

 Native calx of arfenic. Kirivan miner, i, p. z^Z, 

 White oxyde of arfenic. SchmeiJJer miner. 2 p. 263, 

 Native oxyde of arfenic. Thomfon chem, 4. /, 103. 

 White arfenic. Berkenh Jyn. p. 268, 



1. fn a look dull or mealy powder. 

 Wall, fy St. miner, 2. /». i6o. ff. i . a. 



Loofe native calx of arfenic. Kirixan min, 2. />, 258, 



2. In a ftute of cryftallization. 



Arfenicum cryllall. Syft. nat. xii, 3. /. 117, », i. 

 Wall, fyjh miner. 2, ^. 160. «. 1, b. 



3. In an indurated ftate combined with earth. 

 Arfenic. terra mineral. Wall.fyjt. 2. p, 169. «. 10, 

 Indurated native calx. Ki^^nxjan miner. 2. p, 259. 



Found in various parts of Great-Britain, Germany, Hungary, 

 Saxony, Bohe?nia, &c. either in powder or maffive or cryftaU 

 Jized in prifmatic needles : colour white or grey, with often 

 a tinge of red, yellow, green or black : before the blowpipe 

 it fublimes but does not inSame, and tinges borax green % 

 fpecific gravity 3,700. 



Auripig- Ponderous, yellow, curved or undulately foliated, of a 

 mentum. waxy internal kiltre, evaporating almoft entirely be- 



fore the blowpipe. 

 Pyrites nudus. Syfl. nat^ xii. 3. ^. n 3. n. 2. 

 Arfenicum flavum. Wall. fyji. 2. p. 163, «, 5, 

 Orpiment. Berkenhout fynopf. p, 268. 

 Orpimcnt, Kir-wan mineral. 2. p, 260. 



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