We describe two experiments to study the influence of fluctuations in
the electron charge on the transport properties of a quantum dot. Firs
t, we scan a device from single- to double quantum-dot behavior by var
ying the conductance of a connecting point contact. Second, we measure
the dependence of the charging energy on the conductance of the barri
ers. The experiments are compared with traces obtained from a modeling
that assumes a scaling behavior of the charging energy. Good agreemen
t is obtained.