  We present experimental results that demonstrate a glassy behavior in the
conductance of quench condensed insulating granular metals that is different
from that observed in continuous disordered systems. Exciting the granular
system by biasing the sample with a high electric field results in a slow
conductance change both during the excitation and during the relaxation back to
its steady state. The time scales for these processes are many orders of
magnitudes longer than the typical hopping time. We find that, initially, this
conductance change has an opposite sign to that observed in similar experiments
performed on continuous films. Only after relatively long times this trend is
reversed and the samples exhibit conventional behavior. We suggest that the
granular systems exhibit a new glassy process related to charge redistribution
among the grains. This process combines with the relaxation processes that are
characteristic of disordered systems to give rise to a unique relaxation
profile.
