THE CAUSE OF FLAMES 63 



collecting on the inside of the test tube? 

 Continue to heat the wood until smoke 

 comes out of the open end. Try lighting 

 this with a match. How does it burn, with 

 a flame or a glow? What must it be? 

 Where did it come from? 



b. Continue to heat the bits of wood 

 until the smoke ceases to come off, then 

 remove from the flame. After the tube 

 has cooled a little pour out what remains 

 from the wood. What does it look like? 

 How does it burn? Why does it burn 

 this way? 



c. Light a candle, let it burn for a short 

 . . ,, time, and then blow it out. Have a burning 

 \ '\ /7 match all ready to hold over the candle. It 



should ignite. What burns? 



d. Light a candle and hold a glass tube in 

 the flame as shown in the illustration. A 

 gas will pass up the tube and may be ignited 

 at the top. Where does the gas come from? 



e. If there is gas, try the experiment as 

 shown in the illustration. 



Review Questions, 14. 



1. What is our guide from which we may learn 

 direction in the open country? How can you find the 

 guide? 



2. What direction is 45 to the east of north? What 

 direction is S. 45 W?. 



