PROCEEDINGS OF THE ROYAL SOCIETY OP LONDON S e r ie s A CONTAINING PAPERS OF A MATHEMATICAL ANT) PHYSICAL CHARACTER. VOL. CVII. LONDON: P rinted fop. THE ROYAL SOCIETY and S old bv HARRISON AND SONS, Ltd., ST. MARTIN’S LANE, PRINTERS IN ORDINARY TO HIS MAJESTY. A pril, J925. LONDON : HARRISON AND SONS, LTD., PRINTERS IN ORDINARY TO HIS MAJESTY, ST. m a r t in ’s LANE. CONTENTS. --- o o ^ O o ---- SERIES A. VOL. CVII. Minutes of Meetings, December 1, 4, 1924 ; January 15, 22, 29, February 5, 12, 19, 26, and March 5, 12, 19, 26, 1925. No. A 741.—January 1, 1925. PAGE Address of the President, Sir Charles S. Sherrington, at the Anniversary Meeting, December 1, 1924 ............................................................................................................... 1 On the Total Reflexion of Light. By Sir Arthur Schuster, For. Sec. R.S.................. 15 The Structure of the Spectrum of Ionised Nitrogen. By A. Fowler, F.R.S., Yarrow Research Professor of the Royal Society, Imperial College, South Kensington. (Plate 1) .................................................................................................. 31 Spheroidal Wave-Functions. By J. W. Nicholson, M.A., D.Sc., F.R.S., Fellow of Balliol College, Oxford.................................................................................................. 43 thermionic Effects caused by Vapours of Alkali Metals. By Irving Langmuir and K. H. Kingdon, of the Research Laboratory, General Electric Company, Schenectady, N.Y. Communicated by Prof. Sir E. Rutherford, F.R.S.............. 61 1:2: 3—Triaminopropane and its Complex Metallic Compounds. By Frederick George Mann, Ph.D., and Sir William Jackson Pope, F.R.S.................................. 80 The Union of Hydrogen and Oxygen in Presence of Silver and Gold. By D. L. Chapman, M.A., F.R.S., Fellow of Jesus College, Oxford ; J. E. Ramsbottoin, D.Sc., Ph.D., Superintendent Chemical Department, Royal Aircraft Establish­ ment, larnborough ; and C. G. Trotman, B.A., Jesus College, Oxford............... 92 The General Law of Electrical Conduction in Dielectrics. By Spencer W. Richardson, M.A., D.Sc., F.Inst.P. Communicated by Sir William Bra^g, K.B.E., F.R.S....................................................................................................................... 101 Recent Developments in Tensile Testing. By J. V. Howard, D.Sc., and S. L. Smith, D.Sc., A.C.G.I. Communicated by W. E. Dalby, F.R.S............................. 113 The Effect of Superposed Alternating Current on the Polarisable Primary Cell Zinc-Sulphuric Acid-Carbon. Part I.—Low-Frequency Current. By A. J. Allmand, D.Sc., and V. S. Puri, M.Sc., Ph.D. Communicated by Prof. S. Smiles, F.R.S....................................................................................................................... 126 The Spark-Spectra of Indium and Gallium in the Extreme Ultra-Violet Region. By Mollie Weinberg, M.A., M.Sc., Physical Laboratory, University of Toronto. Communicated by Prof. J. C. McLennan, F.R.S. (Plate 2)............... 138 IV PAG-E On the Atomic Fields of Helium and Neon. By J. E. Jones, D.Sc., 1851 Exhibition Senior Research Student, Trinity College, Cambridge. Communicated by Prof. S. Chapman, F.R.S................................................................................................... 157 No. A 742.—February 2, 1925. Experiments on the Distortion of Single-Crystal Test-Pieces of Aluminium. By H. C. H. Carpenter, F.R.S., Professor of Metallurgy, Imperial College of Science and Technology, and Miss C. F. Elam, M.A., Armourers’ and Brasiers’ Company Research Fellow. (Plate 3 ) .......................................................................... 171 On the Thirteen Semi-regular Solids of Archimedes, and on their Development by the Transformation of certain Plane Configurations. By D’Arcy Wentworth Thompson, F.R.S................................................................................................................. 181 On the Formation of Water Waves by Wind. By Harold Jeffreys, M.A., D.Sc., Fellow and Lecturer of St. John’s College, Cambridge. Communicated by Prof. G. I. Taylor, F.R.S. (Plates 4 and 5) ............................................................. 189 The Thermal and Electrical Conductivities of some Pure Metals. By F. H. Schofield, B.A., B.Sc. Communicated by Sir Joseph Petavel, F.R.S.................... 206 The Colours Due to Thin Films on Metals. By Ulick R. Evans. Communicated by C. T. Heycock, F.R.S.................................................................................................... 228 On the Quantum Dynamics of Degenerate Systems. By A. M. Mosharrafa, D.Sc., Ph.D. Communicated by Prof. O. W. Richardson, F.R.S....................................... 237 On the Effect of Temperature on the Anomalous Reflection of Silver. By M. de Selincourt, Scholar of Brasenose College, Oxford. Communicated by Prof. F. A. Lindemann, F.R.S......................................................................................... 247 The Catalytic Activity of Copper. Part V.—The Comparison of the Rates of Dehydrogenation of Various Alcohols. By W. G. Palmer, Fellow of St. John’s College, Cambridge, and F. H. Constable, Strathcona Research Student, St. John’s College, Cambridge. Communicated by Sir William Pope, F.R.S. ... 255 The Catalytic Action of Copper. Part VI.—An Explanation of the Repro­ ducibility of the Catalyst, and of the Periodic Change in its Activity, together with some Experiments on the Activation of the Catalyst by Alternate an^ Reduction. By H. Constable, Strathcona Research Student of St. John's College, Cambridge.. Communicated by Sir William Pope, F.R.S. 270 Catalytic Action of Copper. Part VII.—A Study of the Effect of Pressure t> i ^ °^ ^ e^}r^10oenation of Alcohols. By F. H. Constable, Strathcona WUHam Pope F E S St JollI,’s ColleSe> Cambridge. Communicated by Sir 279 A ^ r i a f T p d ,° l“ aking SmaU Pots °f Electrically Fused Refractory ' y r e i S' Tnttoa- Communicated by Dr. W. Rosenhain, F.R.S. 287 ° “ tDym!ndCBAM sTUTer nt °f„ the Critic!‘1 PotentiaIs °f G *** E- «• E. Ruthertod'; US C^-Wge. Communicated by Prof. Sir 291 V PAGE On the Determination of Resistance in Terms of Mutual Inductance. By Albert Campbell, B.A. Communicated by F. E. Smith, F.R.S........................................... 310 The Absorption of X-Rays. By E. C. Stoner, B.A., Lecturer in Physics at Leeds University, and L. H. Martin, M.Sc., 1851 Exhibition Scholar (Melb.), Trinity College, Cambridge. Communicated by Prof. Sir E. Rutherford, F.R.S............ 312 Ionisation by Alpha-Particles in Monatomic and Diatomic Gases. By R. W. Gurney, B.A., Trinity Hall, Cambridge. Communicated by Prof. Sir E. Rutherford, F.R.S............................................................................................................... 332 The Stopping-Power of Gases for Alpha-Particles of Different Velocities. By R. W. Gurney, B.A., Trinity Hall, Cambridge. Communicated by Prof. Sir E. Rutherford, F.R.S....................................................................................................... 340 The Ejection of Protons from Nitrogen Nuclei, Photographed by the Wilson Method. By P. M. S. Blackett, Moseley Research Student of the Royal Society and Fellow of King’s College, Cambridge. Communicated by Prof. Sir E. Rutherford, F.R.S. (Plates 6 and 7) ............................................................. 349 The Apparent Tripling of Certain Lines in Arc Spectra. By T. Royds, D.Sc., Director, Kodaikanal Observatory. Communicated by J. Evershed, F.R.S. (Plate 8 ) ............................................................................................................................... 360 No. A 743.—March 2, 1925. On the Life Statistics of Fellows of the Royal Society. By Sir Arthur Schuster, F R -S....................................................................................................................................... 368 The Thermionic Work-Functions and Photo-electric Thresholds of the Alkali Metals. By O. W. Richardson, F.R.S., Yarrow Research Professor of the Royal Society, and A. F. A. Young, Ph.D., King’s College, London................... 377 On Experiments relating to the Spectrum of Nitrogen. By T. R. Merton, M.A., D. Sc., I.R.S., Professor of -Spectroscopy in the University of Oxford, and J. G. Pilley, B.A.............................................................................. ........................’ ....... 4U The Heat Developed during Plastic Extension of Metals. By W. S. Farren, M.A., and G. I. laylor, I.R.S., Yarrow Research Professor of the Royal Society....... 422 An Experimental Study of the Vibrations in the Blades and Shaft of an Airscrew. By A. I age, A.R.C.Sc., of the Aerodynamics Department, National Physical Laboratory. Communicated by II. Lamb, F.R.S....................................................... 451 Theimal Diffusion Measurements. By T. L. Ibbs, M.C., M.Sc. Communicated by Prof. S. W. J. Smith, F.R.S..................................... ..................................... 470 Overvoltage and Transfer Resistance. By Edgar Newbery, D.Sc., F.I.C., Univer­ sity of Cape Town. Communicated by Prof. Sir E. Rutherford, F.R.S. (Pl&tcs 9-11) .......................... .............. 486 The Magnetic Properties of Iron Crystals. By W. L. Webster, B.A., 1851 Research Student of the University of Toronto. Communicated by Prof. Sir E. Rutherford, F.R.S.............................................................. 496 VI PAGE On the