The results of the previous paper are extended to second-order systems, i.e., systems with inertia. Using a generalized definition of the thermodynamic forces, reciprocal relations for the dissipative coefficients in the equations describing irreversible processes are derived. A dissipation function can again be defined, and it can again be used to express the probability functional for fluctuations.

• Received 13 May 1953

DOI:https://doi.org/10.1103/PhysRev.91.1512