Pronunciation: [lˈe͡ɪdən d͡ʒˈɑː] (IPA) 
The Leyden Jar is an early electrical device that stores static electricity in a glass jar. The spelling of "Leyden Jar" is based on the name of the city of Leiden, where the device was invented in 1745. The word "Leyden" is pronounced /ˈlaɪdən/ in IPA phonetic transcription, with stress on the first syllable. The "J" in "Jar" is pronounced like a "y" sound in English, making the sound /ˈleɪdən jɑr/.
A Leyden jar is an early form of capacitor, which is an electronic component that stores electrical energy in an electric field. It consists of a glass jar or tube filled with a dielectric material, usually a conducting liquid or paste, and an electrode system consisting of a metal rod or foil inside the jar and an external metal coating. It was named after the Dutch physicist Pieter van Musschenbroek's hometown of Leyden (Leiden) in the Netherlands, where it was first developed in the 18th century.
The Leyden jar works on the principle of electrostatic induction. When a voltage is applied across the electrodes of the jar, opposite charges accumulate on the inner and outer surfaces, creating an electric potential difference. This potential difference is stored as electric energy in the jar's dielectric material. When the Leyden jar is discharged, the stored charges flow through a circuit and can be used to power various devices or experiments.
Leyden jars were pivotal in the study of electricity and played a significant role in early experiments on electromagnetism. They were used to generate high-voltage discharges, such as sparks, and were crucial in the development of many electrical devices, including early forms of electric batteries and generators. Despite being superseded by more advanced capacitors, Leyden jars remain an important symbol of early electrical research and innovation.
A jar or bottle, coated usually with tinfoil, used to accumulate electricity.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.
The word "Leyden Jar" is derived from the city of Leiden (also spelled as Leyden), located in the Netherlands. The invention of the Leyden Jar is attributed to the Dutch scientist Pieter van Musschenbroek, who developed it in 1745 while working at the University of Leiden. The device consists of a glass jar or container that stores static electricity, for which it came to be known as the "Leyden Jar". The name acknowledges both the invention's place of origin and the city where it was developed.
