In 1901, Rudolf Wegscheider introduced the principle of detailed balance for chemical kinetics. In particular, he demonstrated that the irreversible cycles A 1 ⟶ ⟶ A 2 ⟶ ⟶ ⋯ ⋯ ⟶ ⟶ A n ⟶ ⟶ A 1 are impossible and found explicitly the relations between kinetic constants that follow from the principle of detailed balance. In 1931, Lars Onsager used these relations in his works, for which he was awarded the 1968 Nobel Prize in Chemistry.