  The chemical abundances of metal-poor stars are excellent sources of
information for setting new constraints on models of Galactic chemical
evolution at low metallicities. In this paper we present an attempt to fit the
elemental abundances observed in the bright, metal-poor giant HD 175305, and
derive isotopic fractions using a parametric model. The observed abundances can
be wellmatched by the combined contributions froms- and r-processmaterial. The
component coefficients of the r- and s-processes are C1 = 3.220 and C3 = 1.134,
respectively. The Smisotopic fraction in this star where the observed
neutron-capture elements are produced is predicted to be f 152+154 =0.582,which
suggests that, even though the r-process is predominantly responsible for the
synthesis of the neutron-capture elements in the early Galaxy, the onset of the
s-process had already occurred at this metallicity of [Fe/H] = -1.6.
