But, before I shew that, let me explain to you--as it is quite necessary
for our purpose--that, though I take a candle and give you, as the general
result, its combustion in the form of a flame, we must see whether
combustion is always in this condition, or whether there are other
conditions of flame; and we shall soon discover that there are, and that
they are most important to us. I think, perhaps, the best illustration of
such a point to us, as juveniles, is to shew the result of strong
contrast. Here is a little gunpowder. You know that gunpowder burns with
flame--we may fairly call it flame. It contains carbon and other
materials, which altogether cause it to burn with a flame. And here is
some pulverised iron, or iron filings. Now, I purpose burning these two
things together. I have a little mortar in which I will mix them. (Before
I go into these experiments, let me hope that none of you, by trying to
repeat them, for fun's sake, will do any harm. These things may all be
very properly used if you take care; but without that, much mischief will
be done.) Well, then, here is a little gunpowder, which I put at the
bottom of that little wooden vessel, and mix the iron filings up with it,
my object being to make the gunpowder set fire to the filings and burn
them in the air, and thereby shew the difference between substances
burning with flame and not with flame.
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