Question #63

There were many different devices used in the 17th and 18th century to study static electricity. One of the main ones was the Leyden Jar. This was invented in 1775 and was used to store electric charges. Today the inner and outer charges store equal (but opposite) charges. The original make of this “jar” was that it was a glass jar filled with water and usually contained a cork with a metal chain passing through it. Today it is made out of dielectric, which is an insulator with a layer of metal foil on the inside and outside. The outside is grounded and a charge is given to the inside, which then creates that equal, but opposite charge. Then when the two surfaces (the outside and the inside) are connected with a conductor there is a spark. This spark makes everything turn back to normal. The amount of charge these devices can store depends on the applied voltage and its capacitance. Which basically means it depends on the area of the foil or metal used, the exact material between the two layers and the thickness of the material. This would be a typical set up:

There was one machine in particular that actually was used in treating various health issues, such as: treating paralysis muscle spasms, and to control heart rates. Those being the main uses but they were also used for filling the body with electricity, drawing sparks from the body, and applying sparks from the generator to the body. These machines were called the Ramsden electrostatic machines. Another interesting fact was that these machines were actually used to charge the Leyden Jar. All you had to do was to touch the top of the Leyden Jar which then formed static electricity which would then be stored in the jar.