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 you have three
precious metals (for you may call platinum a precious metal) worked into
coin, they will be sure to run counter to one another. Indeed, the case
did happen, that the price of platinum coin fixed by the Government was
such, that it was worth while to purchase platinum in other countries, and
make coin of it, and then take it into that country and circulate it. The
result was, that the Russian Government stopped the issue. The composition
of this coin is platinum, 97.0; iridium, 1.2; rhodium, 0.5; palladium,
0.25; a little copper, and a little iron. It is, in fact, bad platinum: it
scales, and it has an unfitness for commercial use and in the laboratory,
which the other well-purified platinum has not. It wants working over
again.
Now, Deville s process depends upon three points, upon intense heat,
blowpipe action, and the volatility of certain metals. We know that there
are plenty of metals that are volatile; but this, I think, is the first
time that it has been proposed to use the volatility of certain
metals such as gold and palladium for the purpose of driving them off
and leaving something else behind. He counts largely upon the volatility
of metals which we have not been in the habit of considering volatile, but
which we have rather looked upon as fixed; and I must endeavour to
illustrate these three points by a few experiments. Perhaps I can best
show you what is required in the process of heating platinum by using that
source of heat which we have here, and which seems to be almost
illimitable namely, the voltaic battery; for it is only in consequence of
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