Henry Cavendish
Cavendish claimed that the force between the two electrical objects gets smaller as they get further apart. If the distance between them doubled, the force would be one quarter what it was before.  This was the basis of the inverse-square law. He explained the concept of electric potential, which he called "the degree of electrification". He developed the thought of all points on a good conductor's surface have the same potential energy beside a common reference point. Having no way to measure electric current, he used his body as a machine which measures strength of electric current. All Cavendish's explorations in his notebook was found and confirmed by James Clerk Maxwell.