Radium, and Other Radio-Active Substances; Polonium, Actinium, and Thorium #260331

What constitutes Fluorescence, Stokes' Law, exceptions thereto, Internal and surface dispersion, Derivation of the word fluorescence, Luminescence, Fluorescent liquids, Fluorescent paint ings and writing, Effect of ultra-violet light, fluorescent solids, fluorescent screens, Willemite, Prof. R. W. Wood's ultra-violet screen, The rhodamin screen for the mercury arc.