Vlll 



Page 



Demonstrators . 



municated by Professor H. B. Dixon, F.RS 400 



On the Modulus of Torsional Kigiclity of Quartz Fibres and its Tem- 

 " perature Coefficient. By Frank Horton, D.Sc., B.A., St. Johns 

 Collesre Cambridge, late Mackinnon Student. Communicated by 

 Professor J. J. Thomson, F.RS. (Abstract) 401 



On the Influence of the Time Factor on the Correlation between the 

 Barometric Heights at Stations more than 1000 Miles apart. By 

 F. E. Cave -Browne-Cave, Girton College, Cambridge. Communicated 

 by Professor Karl Pearson, F.R.S 403 



On the Drift produced in Ions by Electromagnetic Disturbances, and a 

 Theory of Radio-activity. By George W. Walker, M.A., A.RC.Sc., 

 Fellow of Trinity College, Cambridge, Lecturer on Physics in the 

 University of Glasgow. Communicated by Professor A. Gray, 

 F.RS. ..... 414 



On the Ultra- Violet Spectrum of Gadolinium. By Sir William 

 Crookes, D.Sc., F.RS 420 



On the " Blaze-currents " of the Gall Bladder of the Frog. By Alice M. 

 Waller. Communicated by Augustus D. Waller, M.D., F.R.S 423 



On the Compressibility of Gases between One Atmosphere and Half 

 an Atmosphere of Pressure. By Lord Rayleigh, O.M., F.RS. 

 (Abstract) 446 



No. 505. March 16, 1905. 



The Theory of Photographic Processes : On the Chemical Dynamics of 

 Development. By S. E. Sheppard, B.Sc., and C. E. K. Mees, B Sc., 

 Communicated by Sir William Ramsay, K.C.B., F.RS 447 



Polarised Rontgen Radiation. By Charles G. Barkla, D.Sc., B.A., 

 King's College, Cambridge, Oliver Lodge Fellow, University of 

 Liverpool. Communicated by Professor J. J. Thomson, F.R.S. 

 (Abstract) 474 



On the Conversion of Electric Oscillations into Continuous Currents by 

 means of a Vacuum Valve. By J. A. Fleming, M.A., D.Sc., F.RS., 

 Professor of Electrical Engineering in University College, London .... 476 



On an Instrument for the Measurement of the Length of Long Electric 

 Waves, and also Small Inductances and Capacities. By J. A. 

 Fleming, M.A., D.Sc., F.R.S., Professor of Electrical Engineering in 

 University College, London 488 



The Effects of Momentary Stresses in Metals. By Bertram Hopkinson, 

 M.A., Professor of Mechanism and Applied Mechanics in the Uni- 

 versity of Cambridge. Communicated by Professor Ewing, F.R.S 498 



Phosphorescence caused by the Beta and Gamma Rays of Radium. By 

 Cr. T. Beilby. Communicated by Professor J. Larmor, Sec. RS 506 



Phosphorescence caused by the Beta and Gamma Rays of Radium. 

 Part II By G. T. Beilby. Communicated by Professor J. Larmor, 

 bee. R.S KI i 



