INDEX to VOL. CII. (A) Absorption bands, wave-lengtli measurement of (Hartridge), 575. Address of the President, 1922, 373. a- and /3-rays, theory of scattering (Jeans), 437. a-particle passing through matter, changes in charge of (Henderson), 496. «-ray, loss of energy of, in passage through matter (Kapitza), 48. a-ray photographs, analysis of (Blackett), 294. Aluminium crystal, distortion during tensile test (Taylor and Elam), 643. Argon, ionisation by electron collisions (Horton and Davies), 131. Armstrong (E. F.) and Hilditch (T. P.) A Study of Catalytic Action at Solid Surfaces.— Part VIII, 21 ; Part IX, 27. Astbury (W. T.) The Crystalline Structure and Properties of Tartaric Acid, 506. Atmosphere, outer, and theory of meteors (Lindemann and Dobson), 411. Atmospheric disturbances, directional observations of (Watt), 460. Atomic hydrogen, incandescence in (Wood), 1. Backliurst (I.) Variation of the Intensity of Reflected X-radiation with the Tem­ perature of the Crystal, 340. Bakerian Lecture (Taylor and Elam), 643. Berry (A.) and Swain (L. M.) On the Steady Motion of a Cylinder through Infinite Viscous Fluid, 766. /3-rays, scattering of (Wilson), 9. Blackett (P. M. S.) On the Analysis of u-Ray Photographs, 294. Brodetsky (S.) The Line of Action of the Resultant Pressure in Discontinuous Fluid Motion, 361 ; ----- Discontinuous Fluid Motion past Circular and Elliptic Cylinders 542. Cale (F. M.) See McLennan and Cale. Campbell (J. H. P.) See Whytlaw-Gray. Carbon arc ultra-violet spectrum (Simeon), 484. Catalytic Action (Armstrong and Hilditch), 21, 27. Christie (Sir W.) Obituary notice of, xi. Clark (M. L.) See McLennan and Clark. Colloidal behaviour, theory of (Hill), 705. Colloids, periodic opacity of (Holker), 710. Colour vision, investigation by Rayleigh test (Houstoun), 353. Copper films, structure and chemical activity of (Hinshelwood), 318. Cyanogen spectrum, note on origin of (Rayleigh), 453. Davies (A. C.) See Horton and Davies. Davy (N.) See Shaw and Davy. Dobson (G. M. B.) See Lindemann and Dobson. Donnan equilibrium and colloidal theory (Hill), 705. Earthquake wave propagation (Jeans), 554. Eddington (A. S.) The Propagation of Gravitational Waves, 268. XXXV111 Elam (C. F.) See Taylor (G. I.) and Elam (C. F.). Electric discharge, evolution of heat and supply of energy during (Roberts), 72. Electrode potential drop, measurements of, with electrolysis (Marsh and Evans), 328. Electrode, potential, significance of (Heyrovsk^), 628. Electrolytes, opacity of colloids in (Holker), 710. Electrons from tungsten filament, energy of (Jones), 734. Evans (A. E.) See Marsh and Evans. Fluid motion, discontinuous (Brodetsky), 361, 542. Fluid, motion of cylinder through (Berry and Swain), 766 ; of particles in (Jeffery), 161. Fluorescence of sesculin (McLennan and Gale), 256. Gowland (W.) Obituary notice of, xvi. Grace (S. F.) Free Motion of a Sphere in a Rotating Liquid parallel to the Axis of Rotation, 89. Gravitational waves, propagation of (Eddington), 268. Gravitative attraction, effect of temperature on (Shaw), 46. Grove-Hills (E. H.) Obituary notice of, xx. Gyromagnetic ratio, magnitude of (Richardson), 538. Haloes, pleochroic, of various geological ages (Joly), 682. Hartridge (11.) The Coincidence Method for the Wave-length Measurement of Absorp­ tion Bauds, 575. Henderson (G. H.) Changes in the Charge of an a-Particle passing through Matter, 496. Hevrovsky (J.) The Significance of the Electrode Potential, ,628. Hicks (W. M.) On the Mutual Threading of Yortex Rings, 111. Hilclitch (T. P.) See Armstrong and Hilditch. Hill (A. V.) The Potential Difference occurring in a Donnan Equilibrium and the Theory of Colloidal Behaviour, 705. Hinshelwood (C. N.) On the Structure and Chemical Activity of Copper Films, 318. Holker (J.) The Periodic Opacity of Certain Colloids in progressively increasing Con­ centrations of Electrolytes, 710. Horton (F.) and Davies (A. C.) A Spectroscopic Investigation of the Ionisation of Argon by Electron Collisions, 131. Houstoun (R. A.) An Investigation of the Colour Vision of 527 Students by the Rayleigh Test, 353. Hydrogen, incandescence in atomic (Wood), 1. Hydrogen positive rays and field of force (Thompson), 197. Hydrogenation of phenol (Armstrong and Hilditch), 21. Ionisation of argon by electron collisions (Horton and Davies), 131. Ionising potentials, new method for studying (Smyth), 283. Iridescent colour and structure (Rayleigh), 668, 674. Iron and steel at temperatures below 280° C. (Thompson and Whitehead), 587. Jackson (L. C.) and Onnes (H. K.) Investigations on the Paramagnetic Sulphates at Low Temperatures, 678 ; ----- ------ Investigations on the Paramagnetism of Crystals at Low Temperatures, 680. Jeans (J. H.) The Theory of the Scattering of a- and /3-rays, 437 ; ----- The Propaga­ tion of Earthquake Waves, 554. Jeffery (G. B.) The Motion of Ellipsoidal Particles immersed in a Viscous Fluid, 161. Joly (J.) Pleochroic Haloes of Various Geological Ages, 682. XXXIX Jones (J. H.) The Kinetic Energy of Electrons emitted from a Hot Tungsten Filament, 734. Kapitza (P. L.) The Loss of Energy of an a-Ray Beam in its Passage through Matter. Part I.— Air and C02, 48. Kapteyn (J. C.) Obituary notice of, xxix. Kempe (Sir A. B.) Obituary notice of, i. Knott (C. G.) Obituary notice of, xxvii. Light, molecular scattering in vapours and liquids (Ramanathan), 151. Light, scattered by mercury vapour, polarisation of (Rayleigh), 190. Lindemann (F. A.) and Dobson (G. M. B.) A Theory of Meteors, and the Density and Temperature of the Outer Atmosphere to which it leads, 411. Liquid, rotating (Grace), 89 ; (Taylor), 180. Lubrication, cylindrical Journal, at high eccentricity (Stanton), 241. McAulay (A.) Multenions and Differential Invariants.—II, 210. McLennan (J. C.) and others. On the Absorption of X 5460‘97 A. by Luminous Mercury Vapour, 33. McLennan (J. C.) and Cale (F. M.) On the Fluorescence of iEsculin, 256. McLennan (J. C.) and Clark (M. L.) On the Excitation of Characteristic X-Rays from Light Elements, 389. Marsh (S.) and Evans (A. E.) On Measurements of Electrode Potential Drop with Direct and Alternating Current Electrolysis, 328. Mercury vapour, absorption of X 5460 97 A. by (McLennan and others), 33. Meteors, theory of (Lindemann and Dobson), 411. Mosharrafa (A. M.) On the Quantum Theory of the Simple Zeeman Effect, 529. Multenions and invariants (McAulay), 210. Nitrogen, spectrum of active (Rayleigh), 453. Obituary Notices of Fellows deceased :— Kempe (A. B.), i. Grove-Hills (E. H.), xx. Christie (W. H. M.), xi. Walker (G. W.), xxii. Gowland (W.), xvi. Knott (C. G), xxvii. Kapteyn (J. C.), xxix. Onnes (H. K.) See Jackson and Onnes. Paget (Sir R. A. S.) The Production of Artificial Vowel Sounds, 752. Paramagnetic sulphates and crystals at low temperatures (Jackson and Onnes), 678, 680. Quantum theory and electro-magnetic phenomena ( Wilson), 478. Quartz, effect of long grinding on (Ray), 640. Ramanathan (K. R.) The Molecular Scattering of Light in Vapours and in Liquids and its Relation to the Opalescence observed in the Critical State, 151. Ray (R. .C.) The Effect of Long Grinding on Quartz (Silver Sand), 640. Rayleigh (Lord) Polarisation of the Light Scattered by Mercury Vapour near the Resonance Periodicity, 190; ----- Spectrum of Active Nitrogen as Affected by Admixture of the Inert Gases, with Note on Origin of Cyanogen Spectrum, 453; ----- Studies of Iridescent Colour, and the Structure producing it.—I. Colours of Potassium Chlorate Crystals, 668 ; II. Motlier-of-Pearl, 674. * x l Richardson (O. W.) The Magnitude of the Gyromagnetic Ratio, 538. Roberts (J. K.) The Relation between the Evolution of Heat and the Supply of Energy during the Passage of an Electric Discharge through Hydrogen, 72. Rotating liquid, motion of sphere in (Grace), 89 ; (Taylor), 180. Shaw (P. E.) and Davy (N.) The Effect of Temperature on Gravitative Attraction, 46. Sherrington (Sir C. S.) Presidential Address, 1922, 373. Simeon (F.) The Carbon Arc Spectrum in the Extreme Ultra-violet, 484. Smokes, behaviour, number and size of particles (Whytlaw-Gray and others), 600. Smyth (H. D.) A New Method for Studying Ionising Potentials, 283. Speakman (J. B.) See Whytlaw-Gray. Sphere in rotating liquid, motion of (Grace), 89 ; (Taylor), 180. Stanton (T. E.) On the Characteristics of Cylindrical Journal Lubrication at High Values of the Eccentricity, 241. Swain (L. M.) See Berry and Swain. Tartaric acid, crystalline structure and properties (Astbury), 506. Taylor (G. I.) The Motion of a Sphere in a Rotating Liquid, 180 ; ----- Stability of a Viscous Liquid contained between Two Rotating Cylinders, 541. Taylor (G. I.) and Elam (C. F.) The Distortion of an Aluminium Crystal during a Tensile Test, 643. Tensile distortion of aluminium (Taylor and Elam), 643. Thompson (F. C.) and Whitehead (E.) On the Changes in Iron and Steel at Tem­ peratures below 280° C., 587. Thomson (G. P.) The Scattering of Hydrogen Positive Rays, and the Existence of a Powerful Field of Force in the H Molecule, 197. .f Ultra-violet carbon arc spectrum (Simeon), 484. Viscous fluid, motion of particles in (Jeffery), 161. Vortex rays, mutual threading of (Hicks), 111. Vowel sounds, production of artificial (Paget), 752. Walker (G. W.) Obituary notice of, xxii. Watt (R. A. W.) Directional Observations of Atmospheric Disturbances, 1920-21, 460. Whitehead (E.) See Thompson and Whitehead. Whytlaw-Gray (R. and others) Smokes. Part I.—-A Study of Behaviour and Number of Particles, 600. Part II.—Size of the Particles, 615. Wilson (H. A.) On the Scattering of /3-Rays, 9. Wilson (W.) The Quantum Theory and Electromagnetic Phenomena, 478. Wood (R. W.) Spontaneous Incandescence of Substances in Atomic Hydrogen Gas, 1. X-radiation, variation of the intensity of reflected (Backhurst), 340. X-rays, excitation of, from light elements (McLennan and Clark), 389. Zeeman effect, quantum theory of (Mosliarrafa), 529. end of the hundred and second volume (series a). MINUTES OF MEETINGS.—SESSION 1921-22. November 2, 1922. Sir CHARLES SHERRINGTON, President, in the Chair. The following papers were read :— I. “ Polarization of the Light Scattered by Mercury Vapour near the Resonance Periodicity.” By Lord Rayleigh, F.R.S.