  Halpha and Hbeta spectroscopy with the Wisconsin H-Alpha Mapper (WHAM)
reveals a strong concentration of high velocity emission in a ~ 5 by 5 deg area
centered near (l.b) = (27,-3), known as the Scutum Cloud. The high velocities
imply that we are detecting optical emission from near the plane of the Galaxy
out to the tangent point at heliocentric distances of D \gtrsim 6 kpc, assuming
the gas participates in circular Galactic rotation. The ratio of the Halpha to
Hbeta emission as a function of velocity suggests that dust along these lines
of sight produces a total visual extinction of A_v ~ 3 at D ~ 6 kpc. This makes
it possible to use optical emission lines to explore the physical conditions of
ionized gas in the inner Galaxy. At a Galactocentric distance R_G ~ 4 kpc, for
example, we find that the H^+ has an rms midplane density of ~ 1 cm^-3 with a
vertical scale height of ~ 300 pc. We also find evidence for an increase in the
flux of Lyman continuum photons and an increase in the ratio of ionized to
neutral hydrogen toward the inner Galaxy. We have extended the measurements of
E(B-V) in this direction to distances far beyond what has been accessible
through stellar photometry and find E(B-V)/N_H to be near the local mean of 1.7
x 10^-22 cm^2 mag, with evidence for an increase in this ratio at R_G ~ 4 kpc.
Finally, our observations of [NII] 6583, [SII] 6716, and [OIII] 5007 toward the
window reveal that in the inner Galaxy the temperature of the gas and the
ionization state of oxygen increase with increasing height from the midplane.
