46 
red colour, a nonconductor of electricity, of spe- 
cific gravity about 4300. 
14. Platinum is one of the noble metals, of ra- 
ther a duller white than silver, and the heaviest 
body in nature ; its specific gravity being 21500. 
It is not acted upon by any acid menstrua except 
such as contain chlorine ; it requires an intense 
degree of heat for its fusion. 
15. The properties of gold are well known. Its 
specific gravity is 19^77- it bears the same re- 
lation to acid menstrua as platinum : it is one of 
the characteristics of both these bodies, that they 
are very difficultly acted upon by sulphur. 
16. Silver is of specific gravity 10400 ; it burns 
more readily than platinum or gold, which require 
the intense heat of electricity. It readily unites 
to sulphur. The number representing it is 205. 
17* Mercury is the only known metal fluid at 
the common temperature of the atmosphere ; it 
boils at 660°, and freezes at 39° below 0. Its 
specific gravity is 13560. The number represent- 
ing it is 380. 
18. Copper is of specific gravity 8890. It burns, 
when strongly heated, with red flame, tinged with 
green. The number representing it is 120. 
19. Cobalt is of specific gravity 7760. Its point 
of fusion is very high, nearly equal to that of iron. 
In its calcined, or oxidated state, it is employed for 
giving a blue colour to glass. 
20. Nickel is of a white colour : its specific 
gravity is 8820. This metal and cobalt agree with 
iron, in being attractible by the magnet. The 
number representing nickel is 111. 
