  The emission of a scalar with low energy $\omega$, from a $D (4\le D\le 8 )$
dimensional black hole with n charges is studied in both string and
semiclassical calculations. In the lowest order in $\omega$, the weak coupling
string and semiclassical calculations agree provided that the
Bekenstein--Hawking formula is valid and the effective central charge
$c_{eff}=6$ for any D. When the next order in $\omega$ is considered however,
there is no agreement between the two schemes unless D=5, n=3 or D=4, n=4.
