  Although variations in elemental abundance ratios in the Milky Way Galaxy
certainly exist, details remain uncertain, particularly in the inner Galaxy,
where stars and H II regions in the Galactic plane are obscured optically. In
this paper we revisit two previously studied, inner Galaxy H II regions:
G333.6-0.2 and W43. We observed three new positions in G333.6-0.2 with the
Kuiper Airborne Observatory and reobserved the central position with the
Infrared Space Observatory's Long Wavelength Spectrometer in far-infrared lines
of S++, N++, N+, and O++. We also added the N+ lines at 122 and 205 micron to
the suite of lines measured in W43 by Simpson et al. (1995). The measured
electron densities range from ~40 to over 4000 cm-3 in a single H II region,
indicating that abundance analyses must consider density variations, since the
critical densities of the observed lines range from 40 to 9000 cm-3. We propose
a method to handle density variations and make new estimates of the S/H and N/H
abundance ratios. We find that our sulfur abundance estimates for G333.6-0.2
and W43 agree with the S/H abundance ratios expected for the S/H abundance
gradient previously reported by Simpson et al. The estimated N/H, S/H, and N/S
ratios are the most reliable because of their small corrections for unseen
ionization states (< 10%). We compute models of the two H II regions to
estimate corrections for the other unseen ionization states. We discuss these
predictions and conclude that only a few of the latest models adequately
reproduce H II region observations, including the well-known, relatively-large
observed Ne++/O++ ratios in low- and moderate-excitation H II regions.
