  The magnetic state of the noncentrosymmetric antiferromagnet CeNiC$_2$ has
been studied by magnetic susceptibility, heat capacity, muon spin relaxation
($\mu$SR) and inelastic neutron scattering (INS) measurements. CeNiC$_2$
exhibits three magnetic phase transitions at $T_{N_1}$ = 20 K, $T_{N_2}$ = 10 K
and $T_{N_3}$ = 2.5 K. The presence of long range magnetic order below 20 K is
confirmed by the observation of oscillations in the $\mu$SR spectra between 10
and 20 K and a sharp increase in the muon depolarization rate. INS studies
reveal two well-defined crystal electric field (CEF) excitations around 8 and
30 meV. INS data have been analyzed using a CEF model and the wave functions
were evaluated. We also calculated the direction and magnitude of the ground
state moment using CEF wave functions and compare the results with that
proposed from the neutron diffraction. Our CEF model correctly predicts that
the moments order along the $b-$axis (or $y$-axis) and the observed magnetic
moment is 0.687(5) $\mu_B$, which is higher than the moment observed from the
neutron diffraction (0.25 $\mu_B$/Ce). We attribute the observed reduced moment
due to the Kondo screening effect.
