FLAME. 45 



A. Because any " al'kali" (such as 

 potash) will arrest the hydrogen (as it 

 escapes from the fuel), and prevent its 

 combination with the oxygen of air. 



Q. What is an al'kali ? 



A. The con'verse of an acid; as 

 bitter is the con'verse of sweet, or insipid 

 the con'verse of pungent. 



Q. Why does a JET of FLAME sometimes burst 

 into the room THROUGH THE BARS OF A STOVE ? 



A. The iron bars conduct heat to 

 the interior of some lump of coal : and 

 its volatile gas (bursting through the 

 weakest part) is kindled by the 

 glowing coals over which it passes. 



Q. Why is this JET sometimes of a GREENISH 



YELLOW Colour ? 



A. When a lump of coals lies over 

 the hot bars, or the caals below it are 

 not red hot, the gas which bursts from 

 the lump escapes unburnt, and is of a 

 greenish colour. 



Q. Why does the gas escape UNBURNT ? 

 A. Because neither the bars nor 

 coals (over which it passes) are red-hot. 



