  We propose an empirical sulphur abundance determination method based on the
strong sulphur emission lines, [S II] 6716, 6731 and [S III] 9069, 9531 in H II
regions. From a compilation of literature data we have made a calibration of
sulphur abundance versus ([S II] + [S III])/Hbeta, similar to what has been
widely used for the more easily observable iso-electronic element oxygen. This
enables abundance determinations in extragalactic H II regions without
measurements of weak temperature sensitive lines for use in model calculations.
  As a first application of the empirical calibration 15 spectra covering the
wavelength range 3650-10000 AA have been obtained of H II regions at various
galactocentric distances in the spiral galaxy NGC 300, by employing specially
designed multiaperture slitmasks which allow simultaneous observations of
several H II regions. Sulphur and oxygen abundances are determined and an
oxygen gradient in agreement with previously published work is found as well as
a somewhat steeper sulphur abundance gradient. This results in a slight
decrease of log S/O with increasing radius.
  The quite low values of S/O seem to confirm the trend demonstrated by Diaz et
al. (1991) of a decrease in log S/O at high metallicities, but still more data
are needed before any definite conclusions can be drawn. We find as expected
that the radiation softness parameter eta decreases with increasing radius and
the slope is comparable to what is found for spiral galaxies of similar
metallicity.
