  We consider an ideal gas of massive hadrons in thermal and chemical
equilibrium. The finite-size gas expands longitudinally in accordance with
Bjorken law. Also the transverse expansion in a form of the rarefaction wave is
considered. We show that J/Psi suppression in such an environment, when
combined with the disintegration in nuclear matter, agrees qualitatively well
with NA38 and NA50 data.
