We propose to test current unifying models of active galactic
 nuclei by searching for and studying broad mid-infrared hydrogen
 recombination lines in several Seyfert 2/narrow line X-ray galaxies.
 Our observations will:
 1) provide a qualitative test for such unifying models by
    succeeding or failing to detect a classical broad line
    region (velocity width >3000 km/s) in each of these sources
    at wavelengths where the interstellar dust obscuring the
    nuclei likely becomes transparent;
 2) give quantitative estimates of the column of obscuration
    for material moving at different velocities;
 3) establish the physical properties of the obscuring dust
    particles by determining an extinction curve from line
    ratios.
 Points 2) and 3) taken together will give valuable information
 on the location of the obscuring medium, be it a very thick,
 parsec scale torus, or the nuclear molecular cloud layer on
 10^2 pc scale.
 The key lines required for this study lie at wavelengths where
 the Earth's atmosphere has no or poor transmission.