CHEMICAL HISTORY OP A CANDLE 



157 



Here is an experiment which I think will help you in part 

 in this way. We will put our candle there, and place over it 

 a chimney, thus. I think my candle will go on burning, 

 because the air-passage is open at the bottom and the top. 

 In the first place, you see the moisture appearing that you 

 know about. It is water produced from the candle by the 

 action of the air upon its hydrogen. But, besides that, some- 

 thing is going out at the top: it is not moisture it is not 

 water it is not condensible; and yet, after all, it has very 

 singular properties. You will find that the air coming out 



FIG. 83 



of the top of our chimney is nearly sufficient to blow the 

 light out I am holding to it; and if I put the light fairly 

 opposed to the current, it will blow it quite out. You will 

 say, that is as it should be, and I am supposing that you 

 think it ought to do so, because the nitrogen does not sup- 

 port combustion, and ought to put the candle out, since the 

 candle will not burn in nitrogen. But is there nothing else 

 there than nitrogen ? I must now anticipate that is to say, I 

 must use my own knowledge to supply you with the means 

 that we adopt for the purpose of ascertaining these things, 

 and examining such gases as these. I will take an empty 

 bottle here is one and if I hold it over this chimney, I 



