Leyden jar, c 1780-1798.
© Science Museum / Science & Society Picture Library
Large Leyden jar with wooden cap fitted with metal hook and short length of chain. This was a device for storing an electrical charge, or capacitor, which the Italian physiologist, Luigi Galvani (1737-1798) used with an electrostatic machine to research the effects of electricity on animal nerves and muscles. Galvani's name is still asociated with electricity (galvanism) and his discoveries led to the invention of the voltaic pile, a kind of battery.