Empirical curves of growth for the ion states and molecular hydrogen levels detected in the LLIV Arch toward PG 0804+761. The ions collectively fit on a curve of growth with ﹩b=8﹩ km s﹩^{-1}﹩, defined by four Fe II lines. The data points for these lines are shown together with their wavelengths. The molecular hydrogen lines from ﹩J=0﹩ and ﹩J=1﹩ fit on a curve of growth with ﹩b=6﹩ km s﹩^{-1}﹩. The individual species are labeled in the lower right corner.