The method to derive the rate matrix K of a chemical reaction in a dir
ect and straightforward way is here completed with the introduction of
a new rule due to the application of the detailed balance principle.
This principle let us discover a further characteristic of the rate ma
trices for cyclic reactions, a characteristic that can be used both to
check the validity of the rate matrix and to improve the mechanical m
ethod used to derive the structure of these matrices in a straightforw
ard way.