CHAPTER VI 

 OXIDATION AND ITS RELATION TO LIFE 



BURNING 



The Discovery of Fire. There was a time in the history of the 

 race when fire was not known. There are many ways in which it 

 may have been discovered. It may have been from lightning, 

 from volcanoes, or from oil-wells, which have often burned for 

 hundreds of years after being set on fire. 



Fire has done much to advance civilization. The primitive 

 savage learned to cook his food, to get warmth for his crude home, 

 and to have a light as a protection against the long, cold nights 

 when wild beasts were on all sides ready to devour him. 



Next, fire became a thing of interest in the home. People 

 gathered around the hearthstone, and were taught by its influence 

 to become more social. To-day the whole social world owes a 

 great deal to fire and its resultant forces, steam, which furnishes 

 power for our boats, trains, and lighting systems, and heat, which is 

 so important in every walk of life. 



Cause of Burning. Place a lighted candle in a dish containing about 1 inch 

 of water. Invert over the candle a tall olive bottle, standing in the water. 



The water will gradually rise in the bottle a few inches and the candle will 

 go out. 



Something has caused a partial vacuum in the bottle, thus 

 allowing the water to be pushed up into the bottle. Spmething which 

 caused the candle to burn seems to have disappeared, since the 

 candle went out before the vacuum was complete enough to raise 

 the water to the level of the flame. The part of the air which 

 seems to have disappeared, and which caused the candle to burn, 

 was oxygen. 



Experiment with Oxygen. Fill a deep " cake tin " nearly full of water. 

 Make a zinc shelf to this tin by bending a zinc strip about 3 or 4 inches wide 



135 



