Cbeon? of Electricity 43 



ver, for instance, will have to weigh nearly 

 twice as much as the iron in order to contain 

 the same number of atoms, but it will absorb 

 the same amount of heat as the piece of iron 

 containing the same number of atoms, if both 

 are raised to the same temperature. In view 

 of the above fact it seems that heat acts es- 

 pecially upon the atoms of matter and is a 

 peculiar form of atomic motion. Heat is one 

 kind of motion of the atoms, while electricity 

 may be another form of motion of the same. 

 The two motions may be carried on together. 

 The earth has a compound motion. It re- 

 volves upon its axis once in twenty-four hours, 

 and it also revolves around the sun once each 

 year. So you see that there are different kinds 

 of motion that may be communicated to the 

 same body all producing different results. 



The motion of the individual atom as heat 

 may be, and is, as rapid as light itself when 

 the temperature is sufficiently high, but it does 

 not travel along a conductor rapidly as the 

 electro-atomic motion will. If we apply heat 

 to the end of a metal rod it will travel slowly 

 along the rod. But if we make the rod a con- 

 ductor of electricity it travels from atom to 

 atom with a speed nearer that of the light ray 

 through the ether. Some modern writers have 

 attempted to explain all the phenomena of 

 electricity as having their origin in a certain 

 >f forces upon tin < -thcr, and there is no 



