Metastable spin-magnetized gases can exhibit unusual magnetohydrodynam
ic properties. The gas relaxation to a stable spin compensated state r
eleases chemical energy and can lead to interesting chemical and radia
tive phenomena. Such a gas could be produced by the strong magnetic fi
elds of the z-pinch necks or by pulling out of electrons with non-comp
ensated spins from a ferromagnetic electrode by a strong current disch
arge.