ABSTRACT
William Gilbert, in the sixteenth century, proved that many other substances are ‘electric’and that they have two electrical effects. When rubbed with fur, amber acquires ‘resinous electricity’; glass, however, when rubbed with silk, acquires ‘vitreous electricity’. Electricity repels the same kind and attracts the opposite kind of electricity. Scientists thought that the friction actually created the electricity (their word for charge). They did not realize that an equal amount of opposite electricity remained on the fur or silk.
