A note on the formation of stellar absorption lines

Microphotometer measures of the total absorptions of lines of O II within the wing of Hγ, and of CaH within the wing of HЄ, show departures from the normal absorptions predicted from the multiplet intensities of these lines. The departures increase with the wing absorption, but the effect is more pronounced for O II than for CaH. Eddington's theory of absorption lines leads to a theoretical evaluation of the effect. The remaining discrepancies between this theory and actual observation are unexplained.