FIRE—MKTULLERGY.
19
which is defined to consist in the consumption of pureoxygen gas; for without a proper supply of that element,no ignition can take place. We have been repeatedly wit-ness to experiments in this science, when we have seen ironconsumed with the same rapidity as though it were aresinous substance.
M etullerg Y. —W e speak of the origin of this art preciselyunder the same circumstances in which we discussed the lastarticle: but that its discovery must have been nearly coevalwith the discovery of fire we have little reason to doubt. Byinference, this is most evident; as neither could metalshave been dispensed with for almost every purpose ofhuman life ; or could human existence have been renderedsecure without the assistance of the ignitious and metallic. elements. The social compact could not have beenformed or at least not preserved, without them. Citiescould not have been built, or the most common necessi-ties supplied, without their aid. Of metals the speciesare most various; but nearly all are discovered by the agencyof fire. The more valuable are the most scarce, most dense,and most ductile ; among which are classed silver and gold.But the most invaluable are such as are easiest procured ;iron, for instance, with copper, tin, and lead.
Mineralogists have classed the varieties of metals, andestimated their intrinsic value by many standards. Someare semi-metals, some in a liquid state, and others mixedwith some different metal; but semi-metals, from alliance,are found to be nearly analogous, in many of their properties,with the metal in the vicinity of which they are discovered.
The modern Metullergists thus arrange the variousmetals now discovered to exist, which, with the various de-grees of heat necessary to fuse them, according to Wedg-wood’s Pyrometer are .'s follow:
Chym.
Char.
Name.
Degree.
cES!’
Degree.
n
447°
8
Cobalt .
17977“
8
Bismuth.
476
i
17977
h
Lead .
612
8
Nickel .
20577
5
Mercury boils • •
660
$
21637
0
Zinc .
700
s
Magauese • • • •
21877
t
Antimonv •••■
809
30
Platioa .
23177
$
Brass.
3507
‘Tringelen ....
23177
4587
‘Molybdenum • •
23177
‘ ?
D
Silver.
4767
‘Titanium • • • •
23177
0
Gold.
5237
28177
• The metals distinguished by asterisks have their chymical characters expressedby the initial letter of each name surrounded by a circle.
o2