METALS. 8o. Platinum^ 245 
METALS. 
So. PLATINUM. Of a filvery colour not tar- 
nilhcd by the air, very hard and tenacious,^ fono- 
rous, exceedingly malleable and duftile, fpecific 
gravity 23,000: not fufible in any degree of 
heat, but detonating with, nitre : foluble oniy by 
boiling it in 16 times its \s/eight of nitro-muriatic 
acid, and giving the folution firft a yellow and 
then a red-brown, colour; its oxyde precipitated 
from this folution' by the addition of muriate o,t 
ammonia io. the foi:m, of an orauge powder. 
V'onulatum PtATlKUM. 
Platina. Wall.fyP^ ”>tn. a. ”• 7* 
Platina. Watfon Pbihf. TranfaB. 46. n. 496. 
Platina. Kirv:an miner, z. /. 103. Schmeifser min. a. 17- 
Platinum. Thomjon them. \. p. 1 12- be 4./. 21. 
Found near 9 mto in Peru, near Santa Fe in New Granada, and 
" near the village Choce, in mines or mixed .vith iand on the 
banks of rivers, always in the form of fmall fmooih compref- 
fed firainrof the colour of polifhed tin: it ts always com- 
bined with iron, fometimes amounting to an eighth part, 
mav be readily feparated from it by difiblving it in 
mStic alid ; h istheheaviea and moft refraaory of all 
metals and requires a very vehement degree of heat to ren- 
der u liquid ; its tenacity is fuch, that a wire 0,078 of an 
in rfiameter is capable of fiipporiing a weight of 27,431 
pounds avoirdupoife without breaking: it is ealily melted by 
a Rux of powdered glafs, borax, and charcoal : it is 
macnetic from the quantity of iron it contains. In corife- 
of its great malleability, tenacity, durability, and m. 
ftlnbility, it is a very precious metal. 
