 Like Thomson (Kelvin) as noted above, Helmholtz also found a reciprocal relation, and this was another of the ideas noted by Onsager.Rayleigh (1873) (and in Sections 81 and 345 of Rayleigh (1896/1926)) introduced the dissipation function for the description of dissipative processes involving viscosity.More general versions of this function have been used by many subsequent investigators of the nature of dissipative processes and dynamical structures.