138 CORRELATION OF THE PHYSICAL FORCES. 



glass jar two leaves of gold, which I can cause 

 to move to and fro by this rack work. I will 



Fig. 46. 



Fig. 47. 



connect each of these gold leaves with separate 

 ends of this battery, and if I have a sufficient 

 number of plates in the battery I shall be able 

 to show you that there will be some attraction 

 between those leaves even before they come in 

 contact : if I bring them sufficiently near when 

 they are in communication with the ends of the 

 battery, they will be drawn gently together, and 

 you will know when this takes place, because 



