32 NOTES ON THE TWO ELECTRICITIES. 



I found by this addition to the electrical machine, 

 that upon turning the glass cylinder a constant suc- 

 cession of sparks took place between the balls. As 

 the common electrical machine has all its projections 

 rounded off, it does not, when insulated, give off 

 with facility electricity to the atmosphere, or to the 

 surrounding bodies, or withdraw electricity from 

 them. This constant succession of sparks between 

 the balls, must therefore be derived from the machine 

 itself. In order to prove that the electricity thus 

 made manifest was not derived from the atmosphere, 

 I replaced the conductors with the metallic points in 

 their former position, connecting, however, the balls 

 at their extremities with the balls of the conductors 

 of the machine. Upon again turning the glass 

 cylinder, the electric sparks between the balls (fig- 

 6) did not now take place. It was therefore 

 obvious that the metallic points of the insulated con- 

 ductors, instead of supplying additional electricity to 

 the machine by withdrawing it from the atmosphere, 

 withdrew electricity from the machine, and gave it 

 off to the atmosphere ; and in a dark room this was 

 indicated by the appearance of minute sparks of 

 electricity at the metallic points of the conductors. 



40. If heat is a binary compound, of which the 

 elements are the two electricities, is it by the decom- 



