  The measured melting curve $T_{m}(\nu)$ between the crystal and liquid phases
is analyzed using thermodynamics to extract the change of magnetization $\Delta
M$ as a function of the Landau level filling factor \ $\nu,$ near $\nu=1$. \ An
explanation of $\Delta M$($\nu)$ is proposed \ in terms of Skyrmions. \ Near
$\nu=3$, a Wigner crystal is the most probable solid phase, experiments
excluding Skyrmions.
