  Variational principles for magnetohydrodynamics were introduced by previous
authors both in Lagrangian and Eulerian form. In this paper we introduce
simpler Eulerian variational principles from which all the relevant equations
of non-barotropic magnetohydrodynamics can be derived. The variational
principle is given in terms of five independent functions for non-stationary
barotropic flows. This is less then the eight variables which appear in the
standard equations of barotropic magnetohydrodynamics which are the magnetic
field $\vec B$ the velocity field $\vec v$, the entropy $s$ and the density
$\rho$.
