INDEX. 
Porter (Prof. A. W.) on the diffrac- 
tion images formed by a plane 
diffraction-grating, 174, 
Potential required to maintain a cur- 
rent in a gas, on the, 753. 
Preller (C. 8. Du R.) on the age of 
the Lake of Geneva, 416. 
Pump, on a new automatic gas-, 218. 
Radiation, on a possible variation of 
the solar, 78; on the pressure of, 
355; on the secondary, caused by 
the B and y rays ot radium, 669. 
Radioactive gas from crude petro- 
leum, on a, 498. 
substances, on the conduction 
of electricity through high vacua 
under the influence of, 157. 
Radioactivity, on the decay of the 
excited, from thorium, radium, and 
actinium, 373; of various mate- 
rials, on the, 618. 
Radium, on the atomic weight of, 
279; on the decay of the excited 
radioactivity from, 373; on, and 
the electron theory, 410; plan of 
a combination of atoms to have 
the properties of, 528 ; on the slow 
transformation products of, 636; 
on the secondary radiation caused 
by the B and y rays of, 669; on 
the classification of the a rays 
from, 719; on the ionization curves 
of, 726. 
Radium rays, on the penetrating, 
67 ; on the ionization produced in 
gases by, 610. 
Rainbow, on the theory of the, 598. 
Rankine (A. QO.) on the stretching 
and torsion of lead wire beyond 
the elastic limit, 538. 
Rayleigh (Lord) on fluid friction on 
even surfaces, 66; on the electrical 
vibrations associated with thin 
terminated conducting rods, 105; 
on the achromatization of approx- 
imately monochromatic interter- 
ence-fringes by a highly dispersive 
medium, 330; on the open organ- 
pipe problem in two dimensions, 
481. 
Recoherence, on, 165. 
Reid (C.) on aa Eocene outlier off 
the Cornish coast, 289. 
Richardson (L.) on the Keuper and 
Rhetic series in Gloucestershire 
and Worcestershire, 666. 
Richardson (O. W.) on the diffusion — 
763 
of hydrogen through hot platinum, 
1; on the effect of a luminous dis- 
charge on the ionization produced 
by hot platinum in gases, 400. 
Rods, on the electrical vibrations 
associated with thin terminated 
conducting, 105, 276. 
Rollins (W.) on -radium and the 
electron theory, 410. 
Rontgen rays, on the relative amount 
of ionization produced in gases by, 
of different types, 357; on the 
ionization produced in oases by, 
610. 
Rossignol (C. Le) on the rate of 
decay of thorium emanation, 107. 
Rutherford (Prof. E.) on the slow 
transfor mation products of radium, 
636. 
Schott (Dr. G. A.) on the kinetics 
of a system of particles illustrating 
the line and band spectrum, 384. 
Shaw (Dr. P. E.) on coherence and 
recoherence, 165. 
Silver, on the hard and soft states 
in, 262. 
Skinner (Prof.C. A.) on the relation 
of electrode fall in gases to the 
contact potential series, 387. 
Sodium vapour, quantitative deter- 
mination of the anomalous disper- 
sion of, 298. 
Solar radiation, on a possible varia- 
tion of the, and its effect on ter- 
restrial temperatures, 78. 
Solubility, on the theory of, 
704. 
Solutions, a theory of, 158. 
Spark, on the lengthening of the, 
from an induction-coil by the aid 
of auxiliary wires, 487. 
Spectra of the elements and their 
atomic weights, on relationships 
between the, 279. 
Spectrum, on the kinetics of a system 
of particles illustrating the line 
and band, 584. 
Spheres, on a graphical method of 
treating the impact of smooth 
elastic ‘Spheres, 215. 
Spiral waves, on the propagation of 
electric waves along, 417, 
Stretching of lead wire beyond the 
elastic limit, on the, 538. 
Strings, on the vibrations of, excited 
by plucking and by resonance, 
O79, 
