Greeks• Over 2,000 years ago, the Greeks discovered that amber rubbed with fur attracts light objects, such as dust or feathers. Two rubbed amber rods were found to repel each other.
Otto Von Guerike• Made a large ball of sulfur which he could rotate with one hand and rub with the other. Apart from being able to attract small pieces of paper, it (rather unexpectedly) produced a crackle and minute sparks in the process of rubbing.
Benjamín Franklin• saw the connection between the tiny electric sparks from a sulfur ball and the huge sparks of lightning – they were both flows of electric "fluid." He proved his point in his famous experiment where the moist cord from a kite flying in a thundercloud conveyed the electrical charge in the thundercloud to earth.
Louis Galvani• The Italian Galvani made another important, though accidental, discovery toward the end of the 18th century. He found that wires of brass and iron in contact with the leg of a recently killed frog made its muscles contract, as they contracted when the store of electricity from a Leyden jar was passed through the leg. Galvani thought that the leg had, in some mysterious way, produced electricity on its own.
Alessandro Volta• He showed that the muscular contraction of the frogs leg observed by Galvani had nothing to do with the frog itself, but was caused by the brass and iron wires in contact with the salty moisture in the legs. In fact, they made a primitive form of electric cell. Volta made his own electric cell from plates of copper and zinc in a solution of salt. He went on to construct a more useful battery (or pile as it was called) by joining a number of cells together.