Leyden-jar

noun, Electricity.
1.
a device for storing electric charge, consisting essentially of a glass jar lined inside and outside, for about two-thirds of its height, with tinfoil.
noun
1.
(physics) an early type of capacitor consisting of a glass jar with the lower part of the inside and outside coated with tin foil
n.

1755, phial used for accumulating and storing static electricity, from Leyden (modern Leiden), city in Holland; so called because it was first described (in 1746) by physicist Pieter van Musschenbroek of Leyden (1692-1761). The place name is said to be from Germanic *leitha- “canal.”
Leyden jar
(līd’n)
An early device for storing electric charge that uses the same principle as a modern capacitor. It consists of a glass jar with conductive metal foil covering its inner and outer surfaces, with the glass insulating these surfaces from each other. The inner surface is charged (by an external source) through an electrode penetrating the top of the jar; the inner and outer foil layers can then hold an equal and opposite charge.