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Common Science 



this: The heat from the flame above was conducted 

 out to the sides by the wire screen as soon as it reached 

 the screen; so very little heat could get through the 

 screen to the gas below. Therefore the gas below the 

 screen never got hot enough for the chemical change of 

 oxidation, or burning, to take place. So the gas below 

 it did not catch fire. 



Another simple experiment with the Bunsen burner, 

 that shows the same thing in a different way, is this : 



Experiment 98. Light the Bunsen burner. Open the air 

 valve at the bottom all the way. Hold the wood end of a 

 match (not the head) in the center of the inner greenish 

 cone of flame, about half an inch above the mouth of the 

 burner. Does the part of the match in the center of the 

 flame catch fire? Does the part on the edge? What do 

 you suppose is the reason for this? Where are the cold gas 



FIG. 171. Why doesn't the flame above the wire gauze set fire to the gas below ? 



