We investigate whether dual strings could be solutions of the
magnetohydrodynamics equations in the limit of infinite conductivity. We find
that the induction equation is satisfied, and we discuss the Navier-Stokes
equation (without viscosity) with the Lorentz force included. We argue that the
dual string equations (with a non-universal maximum velocity) should describe
the large scale motion of narrow magnetic flux tubes, because of a large
reparametrization (gauge) invariance of the magnetic and electric string
fields. It is shown that the energy-momentum tensor for the dual string can be
reinterpreted as an energy-momentum tensor for magnetohydrodynamics, provided
certain conditions are satisfied. We also give a brief discussion of the case
when magnetic monopoles are included, and indicate how this can lead to a
non-relativistic "electrohydrodynamics" picture of confinement.Comment: 10 pages. LaTex. A minor correction has been mad