Battery of sixty-four Leyden jars used by Joseph Priestley, 1775. A Leyden jar, or Leiden jar, is a device that "stores" static electricity between two electrodes on the inside and outside of a glass jar. A Leyden jar typically consists of a glass jar with metal foil cemented to the inside and the outside surfaces, and a metal terminal projecting vertically through the jar lid to make contact with the inner foil. It was the original form of a capacitor (originally known as a "condenser"). Joseph Priestley (1733-1804) was an English chemist whose first scientific work, The History of Electricity (1767), was encouraged by Benjamin Franklin. His most famous scientific research was on the nature and properties of gases.