the lead present in it. That you may have a notion of the great power that
platinum has of combining with other metals, I will refer you to a little
of the chemist's experience--his bad experience. He knows very well that
if he takes a piece of platinum-foil, and heats a piece of lead upon it,
or if he takes a piece of platinum-foil, such as we have here, and heats
things upon it that have lead in them, his platinum is destroyed. I have
here a piece of platinum, and if I apply the heat of the spirit-lamp to
it, in consequence of the presence of this little piece of lead which I
will place on it, I shall make a hole in the metal. The heat of the lamp
itself would do no harm to the platinum, nor would other chemical means;
but because there is a little lead present, and there is an affinity
between the two substances, the bodies fuse together at once. You see the
hole I have made. It is large enough to put your finger in, though the
platinum itself was, as you saw, almost infusible, except by the voltaic
battery. For the purpose of shewing this fact in a more striking manner, I
have taken pieces of platinum-foil, tin-foil, and lead-foil, and rolled
them together; and if I apply the blowpipe to them, you will have, in
fact, a repetition on a larger scale of the experiment you saw just now
when the lead and platinum came together, and one spoiled the other. When
the metals are laid one upon the other, and folded together and heat
applied, you will not only see that the platinum runs to waste, but that
at the time when the platinum and lead are combined there is ignition
produced--there is a power of sustaining combustion. I have taken a large
piece, that you may see the phenomenon on a large scale. You saw the
ignition and the explosion which followed, of which we have here the
results--the consequence of the chemical affinity between the platinum and
the metals combined with it, which is the thing upon which Deville founds
his first result.

When he has melted these substances and stirred them well up, and so