think it is but fair that you should see an experiment shewing you the way
in which we get the adhesion of platinum. Probably you all know of the
welding of iron: you go into the smith's shop, and you see him put the
handle of a poker on to the stem, and by a little management and the
application of heat he makes them one. You have no doubt seen him put the
iron into the fire and sprinkle a little sand upon it. He does not know
the philosophy he calls into play when he sprinkles a little sand over the
oxide of iron, but he has a fine philosophy there, or practises it, when
he gets his welding. I can shew you here this beautiful circumstance of
the sticking together of the particles up to the fullest possible
intensity of their combination. If you were to go into the workshops of
Mr. Matthey, and see them hammering and welding away, you would see the
value of the experiment I am about to shew you. I have here some
platinum-wire. This is a metal which resists the action of acids, 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,