JOS FARADAY 



because the wick is large; but if, as Argand did so cleverly, 

 I open a passage to the middle of the flame, and so let air 

 come in there, you will see how much more beautifully it 

 burns. If I shut the air off, look how it smokes; and why? 

 We have now some very interesting points to study: we 

 have the case of the combustion of a candle ; we have the case 

 of a candle being put out by the want of air; and we have 

 now the case of imperfect combustion, and this is to us so 

 interesting that I want you to understand it as thoroughly 

 as you do the case of a candle burning in its best possible 

 manner, I will now make a great flame, because we need 

 the largest possible illustrations. Here is a larger wick 

 [burning turpentine on a ball of cotton]. All these things 

 are the same as candles, after all. If we have larger wicks, 

 we must have a larger supply of air, or we shall have less 

 perfect combustion. Look, now, at this black substance 

 going up into the atmosphere; there is a regular stream of 

 it. I have provided means to carry off the imperfectly- 

 burned part, lest it should annoy you. Look at the soots 

 that fly off from the flame; see what an imperfect combus- 

 tion it is, because it can not get enough air. What, then, is 

 happening? Why, certain things which are necessary to 

 the combustion of a candle are absent, and very bad results 

 are accordingly produced; but we see what happens to a 

 candle when it is burnt in a pure and proper state of air. 

 At the time when I showed you this charring by the ring of 

 flame on the one side of the paper, I might have also shown 

 you, by turning to the other side, that the burning of a 

 candle produces the same kind of soot charcoal, or carbon. 

 But, before I show 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 show 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 



