Elster and Geitel, photo-electric activity and absorption, 207;
photo-electric properties of gelatin, 212; Emanation of radium,
therapeutic use of, 256-259; advantages of, in medicine, 256;
volume of, 257; how obtained, 257; use of, in needles, 258.
Equilibrium amount, meaning of, 254, 255.
Evolution and acceleration of activity, 79; of the universe not
eternal a pane ante, 298.
F.
Faraday and ionisation, 57.
Finality of progress a part, post, 289.
Flahault, experiments on colour of flowers, 108.
Fletcher, A. L., proportionality of thorium and uranium, 26,
G.
Galileo, discovery of Jupiter's moons, 162.