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The Chemistry of a Candle.
HE Wilkinsons were having a small party,-it con
younger members of the family, home for the holidays, had been just admitted to assist after dinner. Uncle Bagges was a gentleman from whom his affectionate relatives cherished expectations of a testamentary nature. Hence the greatest attention was paid by them to the wishes of Mr. Bagges, as well as to every observation which he might be pleased to make.
"Eh! what? you sir," said Mr, Bagges, facetiously addressing himself to his eldest nephew, Harry,-" Eh! what? I am glad to hear, sir, that you are doing well at school. Now-eh? now are you clever enough to tell me where was Moses when he put the candle out?"
"That depends, uncle," answered the young gentleman, on whether he had lighted the candle to see with at night, or by daylight, to seal a letter."
"Eh! Very good, now! 'Pon my word, very good," exclaimed Uncle Bagges. "You must be Lord Chancellor, sir-Lord Chancellor, one of these days."
"And now, uncle," asked Harry, who was a favourite with the old gentleman, "can you tell me what you do when you put a candle out?"
"Clap an extinguisher on it, you young rogue, to be
"Oh! but I mean, you cut off its supply of oxygen," said Master Harry.
"Cut off its ox's-eh? what? I shall cut off your nose, you young dog, one of these fine days."
"He means something he heard at the Royal Institution," observed Mrs. Wilkinson. "He reads a great deal about chemistry, and he attended Professor Faraday's lectures there on the chemical history of a candle, and has been full of it ever since."
"Now, you sir," said Uncle Bagges, "come you here to and tell me what you have to say about this chemical, ch?-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 teach 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
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 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.
66 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 candleflame 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."
"Dear me! Well, I suppose there is a reason for everything," exclaimed the young philosopher's mamma.
"What should you say, now," continued Harry, “if I told you that the smoke that comes out of a candle is the very thing that makes a candle light? Yes; a candle shines by consuming its own smoke. The smoke of a candle is a cloud of small dust, and the little grains of the dust are bits of charcoal, or carbon, as chemists call it. They are made in the flame, and burnt in the flame, and, while burning, make the flame bright. They are burnt the moment they are made; but the flame goes on making more of them as fast as it burns them; and that is how it keeps bright. The place they are made in, is in the case of flame itself, where the strongest heat is. The great heat sepa