  The melting temperature ($T_m$) of a solid is generally determined by the
pressure applied to it, or indirectly by its density ($n$) through the equation
of state. This remains true even for helium solids\cite{wilk:67}, where quantum
effects often lead to unusual properties\cite{ekim:04}. In this letter we
present experimental evidence to show that for a two dimensional (2D) solid
formed by electrons in a semiconductor sample under a strong perpendicular
magnetic field\cite{shay:97} ($B$), the $T_m$ is not controlled by $n$, but
effectively by the \textit{quantum correlation} between the electrons through
the Landau level filling factor $\nu$=$nh/eB$. Such melting behavior, different
from that of all other known solids (including a classical 2D electron solid at
zero magnetic field\cite{grim:79}), attests to the quantum nature of the
magnetic field induced electron solid. Moreover, we found the $T_m$ to increase
with the strength of the sample-dependent disorder that pins the electron
solid.
