78 CHEMICAL AFFINITY. 



collected in the other tube (o). Something is 

 coming out of the water there (at H) which 

 burns [setting fire to the gas], but what comes 

 out of the water here (at o), although it will not 

 burn, will support combustion very vigorously. 

 [The Lecturer here placed a match with a 

 glowing tip in the gas, when it immediately 

 rekindled.] 



Here, then, we have two things, neither of 

 them being water alone, but which we get out 

 of the water. Water is therefore composed of 

 two substances different to itself, which appear 

 at separate places when it is made to submit to 

 the force which I have in these wires, and if I 

 take an inverted tube of water and collect this 

 gas (H), you will see that it is by no means the 

 same as the one we collected in the former ap- 

 paratus (fig. 24). That exploded with a loud 

 noise when it was lighted, but this will burn 

 quite noiselessly it is called hydrogen; and 

 the other we call oxygen that gas which so 

 beautifully brightens up all combustion, but 

 does not burn of itself. So now we see that 

 water consists of two kinds of particles attracting 

 each other in a very different manner to the 

 attraction of gravitation or cohesion, and this 



