Molecular column densities along the sight-line to W49N. Black histograms show the data and blue curves show a multi-Gaussian fit to the data. In the case of the SH data, the red curve indicates a convolution of the multi-Gaussian fit with the hyperfine structure; it is this curve that should be compared with the black histogram (see text). Red boxes indicate the velocity ranges for which results are presented in Tables 1 and 2, with the red numbers at the top showing the integrated column density in units of 10¹² cm^-2. Blue symbols above each panel indicate the velocity centroid and full width at half maximum for each Gaussian absorption component.