In matrix theory the effective action for graviton-graviton scattering is a
double expansion in the relative velocity and inverse separation. We discuss
the systematics of this expansion and subject matrix theory to a new test. Low
energy supergravity predicts the coefficient of the v6/r14 term, a
two-loop effect, in agreement with explicit matrix model calculation.Comment: 15 pages, 1 epsf figure, LaTeX. Minor change