In 600 BC, Thales of Miletus noticed that an animal rubbing on amber produced sparks and attracted small feathers. In 1600, William Gilbert dubbed this phenomenon electricity, because in Greek amber was called electron. In 1705, Francis Hauksbee realized friction produced a glow and sparks, and he built the electric machine. Stephen Gray used Hauksbee's device to prove that electricity flows and can be transported and found that some materials block the flow of electricity while others conduct it. In 1745, Peter van Musschenbroek studied how water could be electrified and created the Leyden Bottle. At the same time, Benjamin Franklin proved that electricity is a fluid that flows through any body, from a person with a lot of it (positive) to someone who doesn't have enough of it (negative). Franklin then famously conducted his kite experiment where he attracted lightening and transmitted its electricity to a lightening rod.