IV CONTENTS OF VOL. XLIX. FIFTH SERIES. 



NUMBER CCXCVIL— FEBEUAEY. 



Page 

 Prof. E. Eutherford on Radioactivity produced in Substances 



by the Action of Thorium Compounds 161 



Mr.'G-. F. C, Searle on the Elasticity of Wires 193 



Dr. Henry Eobert Wright on Photometry of the Diffuse 



Eeflexion of Light on Matt Surfaces 199 



Mr. K. E. Johnson'- on the Theory of the Function of the 



Condenser in an Induction-Coil 216 



Lord Eayleigh on the Passage of Argon through thin Films 



• of Indiarubber 220 



Dr. Charles H. Lees on the Conductivities of certain Hetero- 

 geneous Media for a Steady FJux having a Potential .... 221 

 Mr. S. H. Burbury on the Law of Partition of Kinetic 



Energy 226 



Prof. A. McAulay's Notes on the Electromagnetic Theory of 

 Light. — I. Geometrical Properties of the Wave-Surface &c. 

 II. Eeflexion and Eefractiou at the Boundary of Crystals, 

 treated by a Theorem of Sir William Eowan Hamilton . . 228 

 Intelligence and Miscellaneous Articles : — 



Chemical Effects produced by Becquerel's Eays, by 



M. P. and Mme. Curie 24-2 



On the Chemical Action of the a?-Rays, by P. Villard . . 244 



NUMBER CCXCVIII.— MAECH. 



Mr. J. H. Jeans on the Striated Electrical Discharge 245 



Dr. Louis Trenchard More on the Coincidence of Eefracted 

 Eays of Light in Crystalline Media 262 



Mr. E. Hosking on the Viscosity of Solutions 274 



Dr. Charles H. Lees on the Thermal Conductivities of 

 Mixtures and of their Constituents 286 



Hon. E. J. Strutt on the Discharge of Electricity through 

 Argon and Helium 293 



Mr. H. Morris- A_irey on an Experiment bearing on the 

 Hypothesis of Electrolytic Convection in Geissler-tubes . . 307 



Prof. W. F. Barrett on some JNovel Thermo-Electric Phe- 

 nomena 309 



Dr. Silvan us P. Thompson on Obliquely-crossed Cylindrical 

 Lenses 316 



