How the measurement of residual volume developed after Davy (1800).

H. Davy measured the residual volume of his own lungs in 1800, by inhaling a hydrogen mixture contained in a mercurial air holder. Using the same principle, Nestor Grehant determined the functional residual capacity, and the volume of the dead space, in 1864. Both used a forced breathing method, that was substituted by a prolonged dilution method by D.D. Van Slyke and C.A.L. Binger in 1923. It was in 1941 that G.R. Meneely and M.L. Kaltreider replaced hydrogen with helium. The open circuit nitrogen washout method was proposed by R.E. Darling, A. Cournand and D.W. Richards in 1940, and the body plethysmograph by A.B. DuBois et al. in 1956. So the three methods, still in common use today for measuring the static lung volumes, had been described by the mid-1950s.