  In this work the modified Chaplygin gas is related to a cosmological scalar
field. Analytical results, more general than the solutions previously shown in
the literature, are presented for the case when the curvature is absent, and
one entirely new particular result is shown for a case where there is
curvature. Also, it is emphasized here that one interesting feature of the
scalar field associated to the modified Chaplygin gas is the possible presence
of two minima in its potential. Finally, it is argued that the scalar field
representation of the Chaplygin gas can be another useful tool in the study of
the evolution of perturbations and, as an example of this, a new analytical
result for the density contrast is presented.
