  We present the chemical compositions for eight bright giants in the globular
cluster NGC 1851. Our analysis reveals large star-to-star abundance variations
and correlations of the light elements O, Na, and Al, a feature found in every
well studied globular cluster. However, NGC 1851 also exhibits large
star-to-star abundance variations of the s-process elements Zr and La. These
s-process elements are correlated with Al, and anticorrelated with O.
Furthermore, the Zr and La abundances appear to cluster around two distinct
values. A recent study revealed a double subgiant branch in NGC 1851. Our data
reinforce the notion that there are two stellar populations in NGC 1851 and
indicate that this cluster has experienced a complicated formation history with
similarities to omega Centauri.
