 Thomsen–Berthelot principle

In thermochemistry, the Thomsen–Berthelot principle is a hypothesis in the history of chemistry which argued that all chemical changes are accompanied by the production of heat and that processes which occur will be ones in which the most heat is produced.This principle was formulated in slightly different versions by the Danish chemist Julius Thomsen in 1854 and by the French chemist Marcellin Berthelot in 1864.