Wilson, C. T. R.
ions as nuclei of condensation, 47 et seq.
difference between positive and negative ions as condensation nuclei, 49
equality of charges carried by positive and negative ions, 50
construction of electroscope, 86, 88
natural ionization of air in vessels, 501
radio-activity of rain and snow, 505, 506
loss of charge in closed vessels, 531 et seq., 534
presence of ions in dust-free air shown by condensation, 533
number of ions produced per c.c., 533
effect of pressure and nature of gas on ionization in sealed vessels, 534
Wilson, H. A.
charge on ion, 51
Wilson, W. E.
radium in sun, 491
Wölfl, Hofmann and Gonder
properties of radio-active lead, 27, 413
Wood, A.
radio-activity of ordinary materials, 540
Zara, Levi Da and Vincenti
radium emanation in spring waters, 516
Zeeman
action of magnetic field on light, 77
Zeleny
velocity of ions, 42 et seq.
difference of velocity of ions, 45
potential gradient between electrodes, 65
Zerban and Hofmann
connection of activity of thorium with uranium, 29
Zinc Sulphide
scintillations produced in by α rays, 158
cause of luminosity of, 160, 549
CAMBRIDGE: PRINTED BY JOHN CLAY, M.A. AT THE UNIVERSITY PRESS.
