Unpublished letter and paper, on medical electricity by John Birch Birch's paper describes the application of electricity and electric shocks to treat certain diseases. Birch describes his contributions to and the design of an electric machine, as well as his system of practice developed from years of experiments with electricity. Birch uses his machine to relieve acute pain, stop spasms, revive paralysed muscles, and remove 'obstructions'. Preceded by an introductory letter from Birch to William Watson. Subject: Medicine Written at Essex Street [London]. January 1787