But we must speak of candles as they are in commerce. Here are a couple of candles commonly called dips. They are made of lengths of cotton cut off, hung up by a loop, dipped into melted tallow, taken out again and cooled; then re-dipped until there is an accumulation of tallow round the cotton. However, a candle, you know, is not now a greasy thing like an ordinary tallow candle, but a clean thing; and you may almost scrape off and pulverise the drops which fall from it without soiling anything. The candle I have in my hand is a stearine candle, made of stearine from tallow. Then here is a sperm candle, which comes from the purified oil of the spermaceti whale. Here, also, are yellow beeswax and refined beeswax from which candles are made. Here, too, is that curious substance called paraffin, and some paraffin candles made of paraffin obtained from the bogs of Ireland. I have here also a substance brought from Japan, a sort of wax which a kind friend has sent me, and which forms a new material for the manufacture of candles. Now, as to the light of the candle. We will light one or two, and set them at work in the performance of their proper function. You observe a candle is a very different thing from a lamp. With a lamp you take a little oil, fill your vessel, put in a little moss, or some cotton prepared by artificial means, and then light the top of the wick. When the flame runs down the cotton to the oil, it gets stopped, but it goes on burning in the part above. Now, I have no doubt you will ask, how is it that the oil, which will not burn of itself, gets up to the top of the cotton, where it will burn? We shall presently examine that; but there is a much more wonderful thing about the burning of a candle than this. You have here a solid substance with no vessel to contain it; and how is it that this solid substance can get up to the place where the flame is? Or, when it is made a fluid, then how is it that it keeps together? This is a wonderful thing about a candle.