  In this paper, we report results of the first studies on the thermoelectric
power (TEP) of the magnetic heusler alloy Ni$_{2.19}$Mn$_{0.81}$Ga. We explain
the observed temperature dependence of the TEP in terms of the crystal field
(CF) splitting and compare the observed behavior to that of the stoichiometric
system Ni$_2$MnGa. The resistivity as a function of temperature of the two
systems serves to define the structural transition temperature, T$_M$, which is
the transition from the high temperature austenitic phase to low temperatures
the martensitic phase. Occurrence of magnetic (Curie-Weiss) and the martensitic
transition at almost the same temperature in Ni$_{2.19}$Mn$_{0.81}$Ga has been
explained from TEP to be due to changes in the density of states (DOS) at the
Fermi level.
