  It is shown that the quasi-universal ratio $q=\lim_{T\to0}eS/C\sim\pm1$ of
the Seebeck coefficient to the specific heat in the limit of T=0 observed in a
series of strongly correlated metals can be understood on the basis of the
Fermi liquid theory description. In deriving this result, it is crucial that a
relevant scattering arises from impurities, but not from the mutual scattering
of quasiparticles. The systematics of the sign of $q$ is shown to reflect the
sign of the logarithmic derivative of the density of states and the inverse
mass tensor of the quasiparticles, explaining the systematics of experiments.
In particular, the positive sign of $q$ for Ce-based and $f^{3}$-based heavy
fermions, and the negative sign for Yb-based and $f^{2}$-based heavy fermions,
are explained. The case of non-Fermi liquid near the quantum critical point
(QCP) is briefly mentioned, showing that the ratio $q$ decreases considerably
toward antiferromagnetic QCP while it remains essentially unchanged for the
ferromagnetic QCP or QCP due to a local criticality.
