c4p10-both
The discovery of electricity has so far been accomplished in four clearly distinct stages. The first extends from the time when men first knew of electrical phenomena to the beginning of the natural scientific age; the second includes the seventeenth and the greater part of the eighteenth centuries; the third begins with Galvani's discovery and closes with the first observations of radiant electricity; and the fourth brings us to our own day. We shall here concern ourselves with a few outstanding features of each phase, enough to characterize the strange path along which man has been led by the discovery of electricity.