  We describe two experiments to study the influence of fluctuations in the
electron charge on the transport properties of a quantum dot. First, we scan a
device from single- to double quantum-dot behavior by varying the conductance
of a connecting point contact. Second, we measure the dependence of the
charging energy on the conductance of the barriers. The experiments are
compared with traces obtained from a theory based on a Luttinger liquid type
description. This theory predicts a scaling behaviour of the charging energy,
in good agreement with our experiments.
