118 FARADAY 



over a candle] all the products of that candle, and you v/ill 

 presently see that the tube will become quite opaque. 

 Suppose I take another candle, and place it under a jar, 

 and then put a light on the other side, just to show you 

 what is going on. You see that the sides of the jar become 

 cloudy, and the light begins to burn feebly. It is the 

 products, you see, which make the light so dim, and 

 this is the same thing which makes the sides of the jar so 

 opaque. If you go home, and take a spoon that has been in 

 the cold air, and hold it over a candle not so as to soot it' 

 you will find that it becomes dim just as that jar is dim. 

 If you can get a silver dish, or something of that kind, you 

 will make the experiment still better ; and now, just to carry 

 your thoughts forward to the time we shall next meet, let 

 me tell you that it is water which causes the dimness, and 

 when we next meet I will show you that we can make it, 

 without difficulty, assume the form of a liquid. 



