  We propose that the finite size of the Kondo screening cloud, xi_K, can be
probed by measuring the charge quantization in a one-dimensional system coupled
to a small quantum dot. When the chemical potential, mu in the system is varied
at zero temperature, one should observe charge steps whose locations are at
values of mu that are controlled by the Kondo effect when the system size L is
comparable to xi_K. We show that, if the standard Kondo model is used, the
ratio between the widths of the Coulomb blockade valleys with odd or even
number of electrons is a universal scaling function of xi_K/L. If we take into
account electron-electron interactions in a single-channel wire, this ratio
also depends on the parameters of the effective Luttinger model; in addition,
the scaling is weakly violated by a marginal bulk interaction. For the geometry
of a quantum dot embedded in a ring, we show that the dependence of the charge
steps on a magnetic flux through the ring is controlled by the size of the
Kondo screening cloud.
