CHEMICAL HISTOKY OF A CAND1UB MS 



might come to masses of matter which may be weighed in the 

 balance, and which we can take account of as to hundred- 

 weights and as to tons, as you will see almost immediately. 



Now, as regards this very property of oxygen supporting 

 combustion, which we may compare to air, I will take a piece 

 of candle to show it you in a rough way and the result will 

 be rough. There is our candle burning in the air ; how will it 

 burn in oxygen? I have here a jar of this gas, and I am 

 about to put it over the candle for you to compare the 

 action of this gas with that of the air. Why, look at it; it 

 looks something like the light you saw at the poles of the 

 voltaic battery. Think how vigorous that action must be. 

 And yet, during all that action, nothing more is produced 

 than what is produced by the burning of the candle in air. 

 We have the same production of water, and the same phe- 

 nomena exactly, when we use this gas instead of air, as we 

 have when the candle is burnt in air. 



But now we have got a knowledge of this new substance, 

 we can look at it a little more distinctly, in order to satisfy 

 ourselves that we have got a good general understanding of 

 this part of the product of a candle. It is wonderful how 

 great the supporting powers of this substance are as regards 

 combustion. For instance, here is a lamp which, simple 

 though it be, is the original, I may say, of a great variety 

 of lamps which are constructed for divers purposes for 

 light-houses, microscopic illuminations, and other uses; and 

 if it was proposed to make it burn very brightly, you would 

 say, "If a candle burnt better in oxygen, will not a lamp 

 do the same? " Why, it will do so. Mr. Anderson will give 

 me a tube coming from our oxygen-reservoir, and I am 

 about to apply it to this flame, which I will previously make 

 burn badly on purpose. There comes the oxygen: what a 

 combustion that makes ! But if I shut it off, what becomes 

 of the lamp? [The flow of oxygen was stopped, and the lamp 

 relapsed to its former dimness.] It is wonderful how, by 

 means of oxygen, we get combustion accelerated. But it 

 does not affect merely the combustion of hydrogen, or car- 

 bon, or the candle, but it exalts all combustions of the com- 

 mon kind. We will take one which relates to iron, for 

 instance, as you have already seen iron burn a little in the 



