312 Common Science 



SECTION 47. Burning: Oxidation. 



What makes smoke ? 



What makes fire burn ? 



Why does air keep us alive? 



Why does an apple turn brown after you peel it ? 



If oxygen should suddenly lose its power of com- 

 bining with other things to form compounds, every 

 fire in the world would go out at once. You could 

 go on breathing at first, but your breathing would 

 be useless. You would shiver, begin to struggle, and 

 death would come, all within a minute or two. Plants 

 and trees would die, but they would remain standing 

 until blown down by the wind. Even the fish in the 

 water would all die in a few minutes, more quickly 

 than they usually do when we take them out of the 

 water. In a very short time everything in the world 

 would be dead. 



Then suppose that this condition lasted for hundreds 

 and hundreds of years, the oxygen remaining unable 

 to combine with other elements. During all that time 

 nothing would decay. The trees would stay as they 

 fell. The corpses of people would dry and shrivel, but 

 they would lie where they dropped as perfectly pre- 

 served as the best of mummies. The dead fish would 

 float about in the oceans and lakes. 



This is all because life is kept up by burning. And 

 burning is simply the combining of different things with 

 oxygen. If oxygen ceased to combine with the wood or 

 gas or whatever fuel you use, that fuel could not burn ; 

 how could it when " burning " means combining with 

 oxygen? The heat in your body and the energy with 



