On 11 October 1745 he independently invented the Kleistian jar, more commonly known as the Leyden jar after's Gravesande's graduate student Pieter van Musschenbroek of Leyden.
On 11 October 1745 he independently invented the Kleistian jar which could store electricity in large quantities. This became more commonly known as the Leyden jar after's Gravesande's graduate student Pieter van Musschenbroek of Leyden.