INDEX. 761 
Galvanometers, on an arrangement 
for reading deflexions of, 111. 
Garrett (A. E.) on chemical dis- 
sociation and electrical conduct- 
ivity, 437. 
Garrett (C. A. B.) on coherence and 
recoherence, 165; on the lateral 
vibration of bars, 581. 
Gas, on a radioactive, from crude 
petroleum, 498; on the potential 
required to maintain a current in 
a, 700. 
Gases, on cathode disintegration in 
the discharge through, 145; on 
the rate of recombination of ions 
in, 206, 211; on the relative 
amount of ionization produced in, 
by Roéntgen rays of different types, 
357; on the relation of electrode 
fall in, to the contact potential 
series, 387; on the effect of a 
luminous discharge on the ion- 
ization produced by hot platinum 
in, 400; on the conductivity of, 
contained in small vessels, 556; 
on the ionization produced in, by 
Rontgen and radium rays, 610; 
on the genesis of ions in, 738. 
Gas-pump, on a new automatic, 218. 
Geological Society, proceedings of 
the, 289, 413, 664. 
Gimingham (C. T.) on the rate of 
decay of thorium emanation, 107. 
Gravitation, on the electric origin of, 
685. 
Hardening and softening, on a phase 
theory of, 266. . 
Harrison (Dr. E. P.) on the variation 
with temperature of the magnetic 
permeability of nickel and iron, 
179. 
Haselfoot (C. E.) on the electrical 
effects produced by the explosion 
_ of hydrogen and oxygen, 471. 
Holborn (L.) on cathode disintegra- 
tion in the discharge through gases 
at low pressures, 145. 
Hurst (H. E.) on the genesis of ions 
by the motion of positive ions, 
738. 
Hydrogen, on the diffusion of, through 
hot platinum, 1; on the electrical 
effects produced by the explosion 
of, and oxygen, 471. | 
Images, on the diffraction, formed 
bya plane diffraction - grating, 
174. : 
Impact of smooth elastic spheres, 
on a graphical method of treating 
the, 215. 
Induction-coil, on the lengthening 
of the spark from an, by the aid 
of auxiliary wires, 487. 
Insulation, onelectric,in vacuum, 534, 
Interference-fringes, on the achro- 
matization of approximately mono- 
chromatic, by a highly dispersive 
medium, 524, 
Ionization, on the relative amount 
of, produced in gases by Réntgen 
rays of different types, 357; on 
the ettect of a luminous discharge 
on the, produced by hot platinum 
in gases, 400; on the, produced 
in gases by Rontgen and radium 
rays, 610; on saturation currents 
in, 650. 
Ionization curves of radium, on the, 
726. 
Tons, on the rate of recombination of, 
in gases, 206, 211 ; on the genesis 
of, by the motion of positive ions, 
738. 
Iron, on the variation with tem- 
perature of the magnetic permea- 
bility of, 179; on the magnetization 
of, in bulk, 620. 
Irreversible cycles, on 
theorem for, 509. 
Jaffé (G.) on the conductivity of 
gases contained in small vessels, 
556, 
Jeans (J. A.) on the determination 
of the size of molecules from the 
kinetic theory of gases, 692; on 
the persistence of molecular veloci- 
ties in the kinetic theory of gases, 
700. 
Jukes-Browne (A. J.) on the valley 
of the Teign, 289. 
Kayser (Prot. H.) on new standards 
of optical wave-length, 568. 
Kelvin (Lord) on the front and rear 
of a free procession of waves in 
deep water, 454; on a plan of a 
combination of atoms to have the 
properties of polonium or radium, 
528; cn electric insulation in 
vacuum, 534. 
Kinetic theory of gases, on the 
determination of the size of mole- 
cules from the, 692; on the per- 
sistance of molecular velocities in 
the, 700, 
Clausius’ 
