Thales of Miletus, a greek philosopher, noted that rubbing amber, jet, and a few other substances would enable them to attract feathers or bits of straw or leaves.
This was the first reference pertaining to electricity that we know of.
The first script on this experiment is in the Plato dialog named "Timeo".
The roman Pliny the Elder wrote about similar experiment in A.D. 70 in his "Natural History". He also mentioned schocks given by a torpedo fish.