EXERCISE 9 



In order to understand living things we ought to know a great deal about burning. We all know 

 that air has something to do with burning. 



Problem. How is air related to fire ? 

 What to use. Lighted candle for fire ; jar ; glass plate. 

 What to do. After making certain that the candle will burn in air, cut off 

 the supply of air by inverting the jar over the lighted candle. 



Record. Tell in detail what you saw happen to the candle and to the jar. 

 Conclusion. What do the results show about the relation between air and fire ? 



Questions. 1. How can you tell that it was not the glass of the jar that produced the result? 

 2. How can you tell that the flame was not poisoned by gases given off by the fire ? 



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