128 ELECTRICITY. 



the room. The outside of that wire is covered 

 with gutta-percha; it would not serve to keep 

 the force from you when touching it with your 

 hands, because it would burst through, but it 

 answers our purpose for the present. And so 

 you perceive how easily I can manage to send 

 this power of electricity from place to place by 

 choosing the materials which can conduct the 

 power. Suppose I want to fire a portion of 

 gunpowder, I can readily do it by this transfer- 

 able power of electricity. I will take a Leyden 

 jar, or any other arrangement which gives us 

 this power, and arrange wires so that they may 

 carry the power to the place I wish ; and then 

 placing a little gunpowder on the extremities of 

 the wires, the moment I make the connection 

 by this discharging rod, I shall fire the gun- 

 powder [the connection was made and the gun- 

 powder ignited]. And if I were to show you a 

 stool like this, and were to explain to you its 

 construction, you could easily understand that 

 we use glass legs, because these are capable of 

 preventing the electricity from going away to 

 the earth. If, therefore, I were to stand on this 

 stool, and receive the electricity through this 

 conductor, I could give it to anything that I 



