EXERCISE 26 

 OF WHAT IS THE CENTRAL PAET OF THE FLAME COMPOSED? 



Materials. Glass tubing ; candle flame ; holding clamp or wire ; matches. 



Directions. Prepare a glass tube several inches in length by drawing out one end so as to 

 secure a small opening. With a metal clamp or wire hold it nearly vertical, with the large end 

 down, and place the large end in the center of the candle flame. Bring a lighted match to the 

 tip of the tube and observe what happens. 



After completing this part of the experiment, remove the tube from the flame and allow it to 

 cool. What is the nature of the material which condenses and hardens on the inside of the tube ? 



What are your conclusions, and the reasons for them ? 



NOTE. This exercise may be performed by the teacher in a more striking manner if the tube used 

 is from 8 to 10 inches long and ^ inch in diameter. It should be clamped firmly in position at an 

 inclination of about 45, and its whole length must be heated by passing a flame back and forth along 

 the tube to prevent cooling and condensation of the gas before it reaches the tip of the tube. 



Additional problems. In the above experiment why is it necessary to keep the long tube warm ? 

 When the gas which was discovered at the center of the flame has passed through the bright zone, 

 is it the same kind of gas ? 



With an inverted funnel gather the escaping gas, and try to light it. 



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