  We present new data for the electrical conductivity of foams in which the
liquid fraction ranges from two to eighty percent. We compare with a
comprehensive collection of prior data, and we model all results with simple
empirical formul\ae. We achieve a unified description that applies equally to
dry foams and emulsions, where the droplets are highly compressed, as well as
to dilute suspensions of spherical particles, where the particle separation is
large. In the former limit, Lemlich's result is recovered; in the latter limit,
Maxwell's result is recovered.
