CONTENTS OF VOL. XXVIII. SIXTH SERIES. V 



Page 

 Prof. A. LI. Hughes on the Contact Difference of Potential of 



Distilled Metals 337 



Prof. L. L. Campbell on Disintegration of the Aluminium 



Cathode 347 



Mr. W. Lawrence Bragg on the Crystalline Structure of 



Copper 355 



Prof. J. C. McLennan on the Absorption Spectrum of Zinc 



Vapour. (Plate VI.) 360 



Mr. D. C. H. Florance on Secondary y Radiation 363 



Mr. H. A. McTaggart on Electrification at Liquid-Gas Surfaces 367 

 Mr. L. Isserlis : The Application of Solid Hypergeometrical 



Series to Frequency Distributions in Space. (Plate VII.) . 379 

 Mr. Allan Ferguson on the Surface-tensions of Liquids in 



contact with different Gases 403 



Dr. T. Martin Lowry on an Oxidizable Variety of Nitrogen. 



(Plates VILI.-XI.) 412 



Notices respecting New Books :— 



Dr. A. LI. Hughes's Photoelectricity 416 



NUMBER CLXVL— OCTOBER. 



Prof. E. M. Wellisch : Experiments on the Active Deposit 

 of Radium 417 



Mr. Gervaise Le Bas on the Theory of Molecular Volumes. — 

 Part IV 439 



Dr. "W. F. G. Swann on the Electrical Resistance of Thin 

 Metallic Films, and a Theory of the Mechanism of Con- 

 duction in such Films 467 



Profs. F. C. Brown and L. P. Sieg on the Seat of Light 

 Action in Certain Crystals of Metallic Selenium, and some 

 New Properties in Matter 497 



Mr. Edwin Edser on the Reflexion of Electromagnetic Waves 

 at the Surface of a Moving Mirror 508 



Miss Jadwiga Szmidt on the Distribution of Energy in the 

 Different Types of y Rays emitted from Certain Radio- 

 active Substances 597 



Lieut. H. P. Walmsley on the Distribution of the Active 

 Deposit of Radium in Electric Fields 539 



Sir Ernest Rutherford and Mr. H. Robinson on the Mass and 

 Velocities of the a Particles from Radioactive Substances 

 (Plate XII.) 550 



Prof. Richard C. Tolman on the Relativity Theory : General 

 Dynamical Principles , 570 



Prof. Richard C. Tolman on the Relativity Theory : The 

 Equipartition Law in a System of Particle's 583 



Mr. Ernest Vanstone on the Unit-Stere Theory of Molecular 

 A^olume : A Criticism ' . 600 



Mr. Gervaise Le Bas : A Reply to a criticism of the Unit- 

 Stere Theory 6O7 



