Definition of Leyden jar in English:

Leyden jar

Pronunciation /ˈlīdn ˌjär/ /ˈlaɪdn ˌdʒɑr/


  • An early form of capacitor consisting of a glass jar with layers of metal foil on the outside and inside.

    ‘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’.’
    • ‘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.’


Mid 18th century named after Leyden (see Leiden), where it was invented (1745).