This paper presents some very simplified general treatments which will allow workers to derive equations for any linear kinetic metabolic process. This is done through the use of the Laplace transforms. A general equation is presented to describe the disposition function in Laplace operators for the central compartment of a linear n compartment mammillary model with elimination occurring from any of the compartments. Input functions describes IV bolus, zero-order infusion, intramuscular injection or GI absorption. The Laplace transform for the amount of drug or metabolite in the central compartment is given by the products of the input and disposition functions.