CHEMICAL HISTORY OF A CANDLE 165 



I have also to show you a little more distinctly the his- 

 tory of carbon and oxygen in their union to make carbonic 

 acid. You are now better able to understand this than 

 before, and I have prepared three or four experiments by 

 way of illustration. This jar is filled with oxygen, and here 

 is some carbon which has been placed in a crucible for the 

 purpose of being made red-hot. I keep my jar dry, and ven- 

 ture to give you a result imperfect in some degree, in order 

 that I may make the experiment brighter. I am about to 

 put the oxygen and the carbon together. That this is carbon 

 (common charcoal pulverized) you will see by the way in 

 which it burns in the air [letting some of the red-hot char- 

 coal fall out of the crucible]. I am now about to burn it in 

 oxygen gas, and look at the difference. It may appear to you 

 at a distance as if it were burning with a flame : but it is not 

 so. Every little piece of charcoal is burning as a spark, and 

 while it so burns it is producing carbonic acid. I specially 

 want these two or three experiments to point out what I 

 shall dwell upon more distinctly by-and-by that carbon burns 

 in this way, and not as a flame. 



Instead of taking many particles of carbon to burn I will 

 take a rather large piece, which will enable you to ?ee the 

 form and size, and to trace the effects very decidedly. Here 

 is the jar of oxygen, and here is the piece of charcoal, to 

 which I have fastened a little piece of wood, which I can set 

 fire to, and so commence the combustion, which I could not 

 conveniently do without. You now see the charcoal burn- 

 ing, but not as a flame (or if there be a flame it is the 

 smallest possible one, which I know the cause of, namely, 

 the formation of a little carbonic oxide close upon the sur- 

 face of the carbon). It goes on burning, you see, slowly 

 producing carbonic acid by the union of this carbon or 

 charcoal (they are equivalent terms) with the oxygen. I 

 have here another piece of charcoal, a piece of bark, which 

 has the quality of being blown to pieces exploding as it 

 burns. By the effect of the heat we shall reduce the lump 

 of carbon into particles that will fly off; still every particle, 

 equally with the whole mass, burns in this peculiar way 

 it burns as a coal and not like a flame. You observe a mul- 

 titude of little combustions going on, but no flame. I do 



