74 CHEMICAL AFFINITY. 



amount of this new power at our disposal. 

 Here you see it is [causing the ends of the 

 wires to touch] that is the electric light we 

 used yesterday, and by means of these wires we 

 can cause water to submit itself to this power ; 

 for the moment I put them into metallic con- 

 nection (at A and B) you see the water boiling in 

 that little vessel (c), and you hear the bubbling 

 of the gas that is going through the tube (D). 

 See how I am converting the water into vapour, 

 and if I take a little vessel (E), and fill it with 

 water, and put it in the trough over the end of 

 the tube (i>), there goes the vapour ascending 

 into the vessel. And yet that is not steam, for 

 you know that if steam is brought near cold 

 water, it would at once condense, and return 

 back again to water; this then cannot be steam, 

 for it is bubbling through the cold water in 

 this trough, but it is a vaporous substance, and 

 we must therefore examine it carefully, to see 

 in what way the water has been changed. And 

 now, in order to give you a proof that it is not 

 steam, I am going to show you that it is com- 

 "bustible, for if I take this small vessel to a 

 light, the vapour inside explodes in a manner 

 that steam could never do. 



