50 future's jflfctracles. 



If we rub the wax with the fur and then 

 take it away the wax has a charge of electricity 

 and will attract light objects. If we had rubbed 

 a piece of metal or some good conductor it 

 would have been warmed instead of electrified. 

 In both cases the particles of the substances 

 have been affected, and if the atomic theory is 

 correct and it seems plausible in the former 

 case the atoms are partly put into electrical 

 motion and partly into a state of electrical 

 strain that we call static (standing) elec- 

 tricity; while in the latter case the atoms are 

 put into the peculiar motion that belongs to 

 heat. The former we call electricity, and the 

 latter we call heat. The electro-atomic motion 

 under some circumstances readily turns to 

 heat, which seems to be the tendency of all 

 forms of energy. The electric light is a result 

 of this tendency. All non-conductors, or elec- 

 trics, have a complex molecular structure, and, 

 while their atoms when subjected to friction 

 are put into a state of electrostatic strain, they 

 are not able readily to respond as a conductor 

 of dynamic electricity. The electric-light 

 filament in the incandescent lamp is a much 

 poorer conductor than the copper wire that 

 leads up to it. The copper wire is readily 

 responsive to the electrical influence, but the 

 carbon filament is not. So electrical action 

 that freely passes along the wire, is resisted 

 and becomes heat action in the filament, and 



