1875

Gabriel Lippmann invests the capillary electrometer, which could be used to record electrical activity of the heart: “He was engaged on a study of the relationships between capillarity and electrical effects at the boundary between mercury and a solution of potassium bichromate in dilute sulphuric acid. The measuring instrument was the accidental result of a purely physical investigation” (Burnett, 60-61); It was first used in 1887 by Augustus Waller, London physiologist, in conjunction with a mirror galvanometer, to record electrical activity of a man’s heart ( Burnett, 60-61; Fye II, 861).