What is a Leyden jar?
Q: What is a Leyden jar?
A: A Leyden jar (or Leiden jar) is a device for storing static electricity. It is a large glass bottle, usually lined on both the inside and the outside with some type of metal foil. Some of the early ones had water inside, allowing experimenters to collect a large amount of charge. They are considered to be the first form of electrical storage.
Q: Who invented the first electrical storage jar?
A: The first electrical storage jar was created by Ewald Georg von Kleist on 11 October 1745. He was the dean of the cathedral of Cammin in Pomerania, on the north coast of Germany at that time.
Q: How did von Kleist create his invention?
A: Von Kleist used a small experimental friction generator and thought he might be able to capture and hold a small amount of static electricity in a bottle because he knew that electricity could not pass through glass. He underestimated how much electricity it could actually hold by thousands of times.
Q: What peculiarity allows electricity to continue flowing into the Leyden Jar?
A: A peculiarity of electricity allows it to continue flowing into the bottle provided that there is an electrically conductive surface connected to the earth which neutralises any pressure from charge trying to flow back out. In von Kleist's case, this electrically conductive surface was just his hand but it was enough for him to receive such an electric shock when he accidentally touched a nail driven through its cork that it threw him across the room.
Q: Who gave this invention its name "Leyden Jar"?
A: Pieter van Musschenbroek, who was then University of Leyden's main physics professor, worked out that its storage capacity was vastly improved only if held in one's hand and sent letters about this discovery to scientists in France which gave rise to its name "Leyden Jar".
Q: For how long did this invention remain as main tool for electrical storage?
A: The Leyden Jar remained as main tool for electrical storage until chemical batteries and modern day generators were invented many years later.
