Line profiles observed toward W49N. Top: emission spectra from the ARO 12 m antenna at ≈1′ spatial resolution. Brighter emission below 20 km s^-1 from the W49N H II region-molecular cloud complex has been truncated to allow better viewing of weaker emission from the Galactic plane clouds. Middle: absorption from weaker-lined transitions including CF⁺ studied at the PdBI. Bottom: absorption in stronger and more ubiquitously distributed species observed at the 30 m. The absorption data are plotted as line/continuum ratios, displaced as needed to fit the plot. In some cases the profiles have been scaled to make weak features more easily visible, with a scale factor as shown at the right hand side of the spectrum.