resists
oxidation by heat, and change of any sort; and which, therefore, I may
heat in the atmosphere without any flux. I bend the wire so as to make the
ends cross: these I make hot by means of the blowpipe, and then, by giving
them a tap with a hammer, I shall make them into one piece. Now that the
pieces are united, I shall have great difficulty in pulling them apart,
though they are joined only at the point where the two cylindrical
surfaces came together. And now I have succeeded in pulling the wire
apart, the division is not at the point of welding, but where the force of
the pincers has cut it, so that the junction we have effected is a
complete one. This, then, is the principle of the manufacture and
production of platinum in the old way.

The treatment which Deville proposes to carry out, and which he has
carried out to a rather large extent in reference to the Russian supply of
platinum, is one altogether by heat, having little or no reference to the
use of acids. That you may know what the problem is, look at this table,
which gives you the composition of such a piece of platinum ore as I
shewed you just now. Wherever it comes from, the composition is as
complicated, though the proportions vary:--

Platinum, . . . . . 76.4
Iridium,. . . . . . 4.3
Rhodium,. . . . . . 0.3
Palladium,. . . . . 1.4
Gold, . . . . . . . 0.4
Copper, . . . . . . 4.1
Iron, . . . . . . . 11.7
Osmide of Iridium,. 0.5
Sand, . . . . . . . 1.4
-----
100.5

This refers to the Uralian ore. In that state of combination, as shewn in
the table, the iridium and osmium are found combined in crystals,
sometimes to the amount of 0.5 per cent., and sometimes 3 or 4 per cent.
Now, this Deville proposes to deal with in the dry way, in the place of
dealing with it by any acid.

I have here another kind of platinum; and I shew it to you for this
reason. The Russian Government, having large stores of platinum in their
dominions, have obtained it in a metallic state, and worked it into coin.
The coin I have in my hand is a twelve silver rouble piece. The rouble is
worth three shillings, and this coin is, therefore, of the value of
thirty-six shillings. The smaller coin is worth half that sum; and the
other, half of that. The metal, however, is unfit for coinage. When you
have the two metals, gold and silver, used for coinage, you have a little
confusion in the value of the two in the market; but when