  The potential of a configuration of two Dirichlet branes for which the number
of ND-directions is eight is determined. Depending on whether one of the branes
is an anti-brane or a brane, the potential vanishes or is twice as large as the
dilaton-gravitational potential. This is shown to be related to the fact that a
fundamental string is created when two such branes cross. Special emphasis is
given to the D0-D8 system, for which an interpretation of these results in
terms of the massive IIA supergravity is presented. It is also shown that the
branes cannot move non-adiabatically in the transverse direction. The
configuration of a zero brane and an orientifold 8-plane is analyzed in a
similar way, and some implications for the type IA-heterotic duality and the
heterotic matrix theory are discussed.
