  We calculate the emission and absorption rates of fixed scalars by the
near-extremal five-dimensional black holes that have recently been modeled
using intersecting D-branes. We find agreement between the semi-classical and
D-brane computations. At low energies the fixed scalar absorption cross-section
is smaller than for ordinary scalars and depends on other properties of the
black hole than just the horizon area. In the D-brane description, fixed scalar
absorption is suppressed because these scalars must split into at least four,
rather than two, open strings running along the D-brane. Consequently, this
comparison provides a more sensitive test of the effective string picture of
the D-brane bound state than does the cross-section for ordinary scalars. In
particular, it allows us to read off the value of the effective string tension.
That value is precisely what is needed to reproduce the near-extremal 5-brane
entropy.
