An early form of capacitor consisting of a glass jar with layers of metal foil on the outside and inside.
- ‘It is easy to imagine Ben Franklin practicing abduction when he first witnessed a spark discharge from the Leyden jars in which he had stored large electric charges.’
- ‘The Leyden jar is a primitive capacitor, first used for containing electrical spirits and demons by Rabbi Levi of Prague in the sixteenth century.’
- ‘One experimenter described to the Royal Society an encounter with a Leyden jar - a primitive capacitor - that left him with a bleeding nose and ‘a heaviness in my head, as if I had a stone lying upon it’.’
Mid 18th century: named after Leyden(see Leiden), where it was invented (1745).