Often the electroscope will have a pair of suspended pith balls.
2.
This allows one to tell at a glance whether the pith balls are charged.
3.
In the axes of the tube is a glass thread, the lower end of this holds a bar of gum lac, with a gilt pith ball at each extremity.
4.
The pith ball can be charged by touching it to a charged object, so some of the charges on the surface of the charged object move to the surface of the ball.
5.
In summary, moving a charged object toward an electroscope's metal rod will indeed cause the rod to gain a force field within the rod that can separate pith balls and pairs of gold leafs.
6.
If one of the pith balls is touched to a charged object, charging it, the second one will be attracted and touch it, communicating some of the charge to the surface of the second ball.