METALS. 82. Argentum. 349 



Found in the gold minfes of Sumatra^ Ne<w Spain^ Hungary^ 

 S^jjei^en and Tran/ylnjania, fometimes in a cryfta'lized foim, 

 and confifts of gold combined with fulphur bv means of ron: 

 the fulphur is difcovered by torrefaftion, the iron by muri- 

 atic acid, and the gold by nitro-muriatic acid. It frequently 

 yields from 50 to 40 ounces of gold iti a hundred pounds 

 weight. 



82. ARGENTUM. Of a filvery colour not tar- 

 nifhed by the air, hard and tenacious, fonorous, 

 exceedingly nnalleable and dudile, fpecific gravity 

 before hammering 10,478: melting when per- 

 fectly red hot and its brilliancy much increafed: 

 foluble in nitric acid, giving no colour to the 

 folution, and may be precipitated from it by 

 copper, iron or zinc* ^ Silver, 



.natlvum. Malleable, du£lile, with a metallic fplendour Internally, 



totally foluble in nitric acid. 



Argentum nudum. 5>y>. nat. xii. 3. p. 148. n.\, 



Argentum nativum. IVall, fyft. 2, p. 328. «. i. 



Native lilver, Kir^w an miner aU 2, p* io8. 



Native lilver. Schmeijferminer. 2. />. 38, 



Nattv'^ (liver. Ihomfon chem. 4. p, 23. 



Capillary Hlver. Sonverby Brit. min. t. 16. 



Found in various parts of Great-Britain^ particularly in the 

 copper mines o{ Corn^'all ; in the mines of Mexico and Peru, 

 and in moll of the mines on the continent : it is rarely to be 

 met with quite pure, but mofl; commonly combined with a 

 greater or lefs proportion of copper, and has fometimes its 

 furface ftriate: it alTumes various forms, and is fometimes 

 found in prifms or cubes: in malleibility it yields only to 

 gold, as it may be beaten out into leaves the 160,000th part 

 of an inch thick ; and may be drawn out to fo fine a wire, that 

 a llngle grain can be extended nearly 400 feet in length ; its 

 tenacity is likewife fuch, that a wire 0,078 of an inch in dia- 

 meter will fupport 17,813 pounds avoirdupoife without 

 breaking: v^hcn melted, if the heat be increafed, the liquid 

 metal boils, and will at !all he volatized : when diiT'lved in 

 nitric acid and precipitated ia lime-water, it f^lls to the bot- • 

 torn in the form of a dark greenifh brown powder: when 

 diffjlved in nitric acid and precipitated with mercury, it 



VOL. VII. — I i 



