We propose to observe with ISO two galaxy clusters to search for dust
distributed in their intracluster medium.  The presence of
intracluster dust has long been controversially been
debated. Observational evidence for dust was indirect, based mainly on
number counts of background objects.  An ISOPHOT observation at 120 um
and 185 um utilizing the C200 array revealed the first direct evidence
for intracluster dust in the Coma cluster of galaxies from FIR
observations. Two scans across the cluster showed an enhanced 120 um
emission about the cluster center. The proposed observations will be
used to extend this measurement to two other clusters, which show
marginal evidence of diffuse extended emission already on 60 and 100
micron IRAS maps.