A process for efficiently computing moments in an interconnected circuit begins by partitioning the circuit into sets of line-like two-port circuits. The rotator is associated with adjustment mechanisms that are actuatable in view of displacing the rotator along the axis of rotation thereof and causing it to selectively move into differentiated positions so as to enable substances having different physical characteristics to be dispensed. Also, stock sensors in the same quantity as the pair of holding members are installed to check for each pair of holding members whether a vial bottle is held on the pair of holding members or not.