Joseph Priestley FRS (/ˈpriːstli/; 24 March 1733 – 6 February 1804) was an English chemist, natural philosopher, separatist theologian, grammarian, multi-subject educator, and liberal political theorist. He published over 150 works, and conducted experiments in electricity and other areas of science. He was a close friend of, and worked in close association with Benjamin Franklin involving electricity experiments.