144 



FARADAY 



FIG. 77 



atmosphere. Here is a jar of oxygen, and this is a piece of 

 iron wire ; but if it were a bar as thick as my wrist, it would 

 burn the same. I first attach a little piece of 

 wood to the iron; I then set the wood on fire, 

 and let them both down together into the jar. 

 The wood is now alight, and there it burns as 

 wood should burn in oxygen; but it will soon 

 communicate its combustion to the iron. The 

 iron is now burning brilliantly, and will con- 

 tinue so for a long time. As long as we supply 

 oxygen, so long can we carry on the combustion 

 of the iron, until the latter is consumed. 



We will now put that on one side, and take some other sub- 

 stance; but we must limit our experiments, for we have not 

 time to spare for all the illustrations you would have a right 

 to if we had more time. We will take a piece of sulphur: 

 you know how sulphur burns in the air; well, we put it into 

 the oxygen, and you will see that whatever can burn in air 

 can burn with a far greater intensity in oxygen, leading 

 you to think that perhaps the atmosphere itself owes all its 

 power of combustion to this gas. The sulphur is 

 now burning very quietly in the oxygen; but you 

 can not for a moment mistake the very high 

 and increased action which takes place when it 

 is so burnt, instead of being burnt merely in 

 common air. 



I am now about to show you the combustion of 

 another substance phosphorus. I can do it better 

 for you here than you can do it at home. This 

 is a very combustible substance; and if it be so 

 combustible in air, what might you expect it would be in 

 oxygen? I am about to show it to you not in its fullest 

 intensity, for if I did so we should almost blow the appa- 

 ratus up; I may even now crack the jar, though I do not 

 want to break things carelessly. You see how it burns in 

 the air. But what a glorious light it gives out when I intro- 

 duce it into oxygen! [Introducing the lighted phosphorus 

 into the jar of oxygen.] There you see the solid particles 

 going off which cause that combustion to be so brilliantly 

 luminous. 



5 



FIG. 78 



