metals. 87. Plumbum. 
a8i 
found in Cornwall, De<vonfiire. tbe Soilly ijlands, ^ndia, Bo- 
hemia, Sai^ony, Sihfta, &c. in or rounded pieces, 
colour dark or blackilb-brown with various fhades of vellow- 
ifh or alby.grey or brownKh red : it is very hard, decrepi- 
tates before the blowpipe, and on charcoal is partly recuced : 
it tin-^es borax white; fpecific gravity from 6, goo. to 6,970. 
contafnstin 77,50. oxygene 21,50. iron 00,25. fihea 00,75. 
Kiapnihi 
Compaft, opakc, ponderous, with a light grey ftreak> in 
the form of cryftals. 
Stannum tcfi'enscrylt. fiyht. nat. xii. 3- p- tS®- ”• 
Stann. arfcnico ■ ryll. W all. lyit. 2. />■ 3^°. n. 2, 3. 
Common tinftonc. Ki-wan miner. 2 p. 197. 
Brown tinftonc. Uchmetjser miner. 2. p. 160. 
Tinftonc, Tbomfondoem, p.b^. o o c Q Br 
Oxygenized tin. Sonveriy But. miner, t. I?. 80 . 81 . 82 . aj- 
Found in all tin mines, (ometinies very fma.l and cluttered 
together) f'.raetinus in larger regular cryftals : colour black 
or brown with generally a fhining lurfacc, rarely red, jel- 
'owilh, or green (h : they are found interfperfed in quartz, 
fluor, or other matrices, or loofe mong the foil or fand ; the 
cryftals are very irregular, the primitive form of which l* 
fuppoled to be a cu^^e, hut they commonly occur in the form 
of double or fingle 4*r)ded pyramids with the edge.s bevilled. 
87. Pl.lTMBUM. Bluifh-white gradually black- 
ening in the air, foft, very malleable, a little 
duftTle and tenacious, not fonorous, ftaining the 
fingers of a bluifh colour, fpeci&c gravity 1 1,35 2: 
eafily m-lting exhibiting iridefeent colours on the 
fuiface dunhg liquefaftion, and becoming firfl a 
white, then a grey, then a yellow, andlaitlv a red 
oxyde, all of which are eafily convertible into 
o-lals : foluble in all acids and giving the lolution 
a fweetifh tafte, precipitating a yciiow powder if 
difiblved in nitric acid and potafs be added to the 
fohition. 
Uncombined. 
Plumbum nudum, S#. naf. i, p- loO. ”■ >- 
Piumbum nativum. W all. miner. 272. 
VOL. VII. — N n 
