  We consider eight-brane configurations in M(atrix) theory and compute their
interaction potentials with gravitons, membranes, and four-branes. We compare
these results with the interactions of D8-branes with D0-branes, D2-branes, and
D4-branes in IIA string theory. We find agreement between the two approaches
for eight-brane interactions with two-branes and four-branes. A discrepancy is
noted in the case with zero-branes.
