44 nature's flfctracles. 



doubt but that the ether plays an important 

 part in all electrical phenomena as a medium 

 through which energy is transferred; but 

 ether-waves that are set in motion by the elec- 

 trical excitation of ordinary matter are no 

 more electricity than the ether-waves set up 

 by the sun in the cold regions of space are heat. 

 They become heat only when they strike mat- 

 ter. Heat, as such, begins and ends in matter ; 

 so (I believe) does electricity. 



Do not be discouraged with these feeble at- 

 tempts to explain the theory of electricity. All 

 I even hope to do is to establish in your minds 

 this fundamental thought, to wit, that there is 

 really but one Energy, and that it is always 

 expressed by some form of motion or the abil- 

 ity to create motion. Motions differ, and 

 hence are called by different names. 



If I should set an emery-wheel to revolving 

 and hold a piece of steel against it the piece 

 of steel would become heated and incandescent 

 particles would fly off, making a brilliant dis- 

 play of fireworks. The heat that has been de- 

 veloped is the measure of the mechanical 

 energy that I have used against the emery- 

 wheel. Now, let us substitute for the emery- 

 wheel another wheel of the same size made of 

 vulcanized rubber, glass or resin. I set it to 

 revolving at the same speed, and instead of 

 the piece of steel, I now hold a silk handker- 

 chief or a catskin against the wheel with the 



