CHEMICAL AFFINITY 



support combustion. Again, here is another experiment 

 which will serve to illustrate the force, if I may so call 

 it, of oxygen. I have here a circular flame 

 of spirit of wine, and with it I am about 

 to show you the way in which iron burns, 

 because it will serve very well as a com- 

 parison between the effect produced by air 

 and oxygen. If I take this ring flame, I 

 can shake, by means of a sieve, the fine 

 particles of iron filings through it, and you 

 will see the way in which they burn. 

 [The lecturer here shook through the flame 

 some iron filings, which took fire and fell 

 through with beautiful scintillations.] But if I now hold the 

 flame over a jar of oxygen [the experiment was repeated over 

 a jar of oxygen, when the combustion of the filings as they 

 fell into the oxygen became almost insupportably brilliant], 

 you see how wonderfully different the effect is in the jar, 

 because there we have oxygen instead of common air. 



FIG. 26 



