you here to me, and tell me what you have to
say about this chemical, eh?—or comical;
which?—this comical chemical history of a
candle."

"He'll bore you, Bagges," said Mr. Wilkinson.
"Harry, don't be troublesome to your
uncle."

''Troublesome! Oh, not at all. He
amuses me. I like to hear him. So let him
leach his old uncle the comicality and chemicality
of a farthing rushlight."

"A wax candle will be nicer and cleaner,
uncle, and answer the same purpose. There's
one on the mantel-shelf. Let me light it."

"Take care you don't burn your fingers,
or set anything on fire," said Mrs. Wilkinson.

"Now, uncle," commenced Harry, having
drawn his chair to the side of Mr. Bagges,
"we have got our candle burning. What do
you see?"

"Let me put on my spectacles," answered
the uncle.

"Look down on the top of the candle around
the wick. See, it is a little cup full of melted
wax. The heat of the flame has melted the
wax just round the wick. The cold air keeps
the outside of it hard, so as to make the rim
of it. The melted wax in the little cup goes
up through the wick to be burnt, just as oil
does in the wick of a lamp. What do you
think makes it go up, uncle?"

"Why—why, the flame draws it up, doesn't
it?"

"Not exactly, uncle. It goes up through
little tiny passages in the cotton wick, because
very, very small channels, or pipes, or pores,
have the power in themselves of sucking up
liquids. What they do it by is called cap—
something."

"Capillary attraction, Harry," suggested
Mr. Wilkinson.

"Yes, that's it; just as a sponge sucks up
water, or a bit of lump-sugar the little drop
of tea or coffee left in the bottom of a cup.
But I mustn't say much more about this, or
else you will tell me I am doing something
very much like teaching my grandmother to
—you know what."

"Your grandmother, eh, young sharpshins?"

"No—I mean my uncle. Now, I'll blow
the candle out, like Moses; not to be in the
dark, though, but to see into what it is. Look
at the smoke rising from the wick. I'll hold
a bit of lighted paper in the smoke, so as not
to touch the wick. But see, for all that, the
candle lights again. So this shows that the
melted wax sucked up through the wick is
turned into vapour; and the vapour burns.
The heat of the burning vapour keeps on
melting more wax, and that is sucked up too
within the flame, and turned into vapour, and
burnt, and so on till the wax is all used up,
and the candle is gone. So the flame, uncle,
you see, is the last of the candle, and the
candle seems to go through the flame into
nothing although it doesn't, but goes into
several things, and isn't it curious, as
Professor Faraday said, that the candle should
look so splendid and glorious in going away?"

"How well he remembers, doesn't he?"
observed Mrs. Wilkinson.

"I dare say," proceeded Harry, "that the
flame of the candle looks flat to you; but if
we were to put a lamp glass over it, so as to
shelter it from the draught, you would see it
is round, round sideways, and running up to
a peak. It is drawn up by the hot air; you
know that hot air always rises, and that is the
way smoke is taken up the chimney. What
should you think was in the middle of the
flame?"

"I should say, fire," replied Uncle Bagges.

"Oh, no! The flame is hollow. The bright
flame we see is something no thicker than a
thin peel, or skin; and it doesn't touch the
wick. Inside of it is the vapour I told you
of just now. If you put one end of a bent
pipe into the middle of the flame, and let the
other end of the pipe dip into a bottle, the
vapour or gas from the candle will mix with
the air there; and if you set fire to the
mixture of gas from the candle and air in the
bottle, it would go off with a bang."

"I wish you'd do that, Harry," said
Master Tom, the younger brother of the juvenile
lecturer.

"I want the proper things," answered
Harry. "Well, uncle, the flame of the candle
is a little shining case, with gas in the inside
of it, and air on the outside, so that the case
of flame is between the air and the gas. The
gas keeps going into the flame to burn, and
when the candle burns properly, none of it
ever passes out through the flame; and none
of the air ever gets in through the flame to
the gas. The greatest heat of the candle is
in this skin, or peel, or case of flame."

"Case of flame!" repeated Mr. Bagges.
"Live and learn. I should have thought a
candle-flame was as thick as my poor old
noddle."

"I can show you the contrary," said Harry.
"I take this piece of white paper, look, and
hold it a second or two down upon the candle-
flame, keeping the flame very steady. Now
I'll rub off the black of the smoke, and—
there—you find that the paper is scorched in
the shape of a ring; but inside the ring it is
only dirtied, and not singed at all."

"Seeing is believing," remarked the uncle.

"But," proceeded Harry, "there is more in
the candle-flame than the gas that comes out
of the candle. You know a candle won't
burn without air. There must be always air
around the gas, and touching it like, to make
it burn. If a candle hasn't got enough air,
it goes out, or burns badly, so that some of
the vapour inside of the flame comes out
through it in the form of smoke, and this is
the reason of a candle smoking. So now you
know why a great clumsy dip smokes more
than a neat wax candle; it is because the
thick wick of the dip makes too much fuel in
proportion to the air that can get to it."