392 
Ions (cont.) 
disturbance of potential gradient by 
movement of, 63 
number of, produced by a particle, 155 
production of, in insulators, 172 
number produced per e.c., in closed 
vessels, 375 
Joly 
absorption of radium rays by at- 
mosphere, 343 (see foot-note) 
Kauffmann 
variation of e/m with velocity of 
electron, 108 et seq. 
Kelvin 
theory of radio-activity, 320 
age of sun and earth, 343, 344 
Kelvin, Smolan and Beattie 
discharging power of uranium rays, 7 
Kunz 
phosphorescence of willemite, and 
kunzite, 168 
Kunzite 
phosphorescence of, under radium 
rays, 168 
Laborde and Curie 
heat emission of radium, 19, 158 
origin of heat from radium, 319 
Langevin 
coefficient of recombination of ions, 38 
velocity of ions, 39 et seq. 
energy required to produce an ion, 55 
secondary radiation produced by X- 
rays, 146 
Larmor 
electrons and matter, 108 
structure of the atom, 126 
radiation from accelerated electrons, 
340 
Lead, radio-active 
preparation of, 26 
radiations from, 26 
Le Bon 
rays from bodies exposed to sunlight, 
5) 
discharging power of quinine sulphate, 
9, 372 
Lenard 
ionization of gases by ultra-violet 
light, 9 
action of ions on a steam jet, 44 
negative charge carried by Lenard 
rays, 102 
absorption of cathode rays propor- 
tional to the density, 113 
Lerch, von 
chemical properties of emanation X, 
275 
INDEX 

Lerch, yon (cont.) : 
electrolysis of solution of emanation 
X, 276 
effect of temperature on excited act- 
ivity, 278 
Lockyer 
inorganic evolution, 349 
Lodge 
connection of heat emission with a 
rays, 164 
instability of atoms, 340 
Lorentz 
structure of atoms, 126 
Lowry and Armstrong 
radio-activity and phosphorescence, 
323 : 
Luminosity 
of radium compounds, 168 
change of, in radium compounds with 
time, 168 
spectrum of phosphorescent light from 
radium bromide, 169 
of radium compounds unaffected by 
temperature, 173 
Magnetic field 
effect of on rays, 92 
deflection of B rays by, 95 et seq. 
nA » a rays by, 117 et seq. 
8 » ‘ions activants” by, 288 
Marckwald 
preparation of radio-tellurium, 21 
Mass 
apparent mass of electron, 107 et seq. 
variation of mass of electron with 
speed, 108 et seq. 
of a particle, 122, 125 
Materials 
radio-activity of ordinary, 370, 378 
Matteucci 
rate of dissipation of charge in closed 
vessels, 373 
McClung 
coefficient of recombination of ions, 
McClung and Rutherford 
energy required to produce an ion, 55 
variation of current with thickness of 
layer of uranium, 149 
estimate of energy radiated from radio- 
elements, 154 
radiation of energy from radium, 317 
McLennan 
absorption of cathode rays, 62 
radio-activity of snow, 356 
excited radio-activity at Niagara Falls, 
366 
McLennan and Burton 
penetrating radiation from the earth, 
366 
