Electroscope n. : An instrument for detecting the presence of electricity, or changes in the electric state of bodies, or the species of electricity present, as by means of pith balls, and the like.

Example:
What happens if you discharge the Electroscope by touching it with your finger?

Taxonomy
electroscope, ball, terminal, pith ball, polarity, leaf electroscope, atoms, the leaves, pith, Gold leaf electroscope, gold leaves, pith balls, electroscopes, gold-leaf, free encyclopedia, magnitude, attraction, presence.

Defination from the web:
electroscope is an early scientific instrument that is used to detect the presence and magnitude of electric charge on a body. ... The first electroscope, a pivoted needle called the versorium, was invented by British physician William Gilbert around ...