VI CONTENTS OF VOL. XXV. — FIFTH SERIES. 



Page 

 Prof. S. P. Thompson on a Modified Water-dropping Influence- 

 machine 283 



Mr. H. Tomlinson on the Effect of Magnetization on the 



Thermoelectrical and other Physical Properties of Bismuth 285 

 Mr. T. H. Blakesley on a Method of Determining the Differ- 

 ence between the Phase of two Harmonic Currents of 



Electricity having the same Period 295 



Mr. J. E. Heyes on Valency, Validity, and Residual Affinity 297 

 Mr. E. J. Smith on the Application of Hydraulic Power to 



Mercurial Pumps 313 



Prof. A. Righi on some Electrical Phenomena provoked by 



Radiation 314 



Proceedings of the Geological Society : — 



Prof. A. H. Green on the Geology and Physical 



Geography of the Cape Colony 316 



Mr. E. Wethered on the Examination of Insoluble 

 Residues obtained from the Carboniferous Lime- 



"stone at Clifton 318 



Mr. T. M. Reade on an Estimate of Post-Glacial Time 319 

 Mr. C. Davison on the Movement of Scree-Material .... 320 

 Mr. G. A. J. Cole on some Additional Occurrences of 



Tachylyte 321 



On the Production of Intense Magnetic Fields, by Prof. Stefan 322 

 Experiments on that Form of the Discharge of Electricity 



known as St. Elmo's Eire, by A. v. Obermayer 323 



Influence of Light on the Thermal Conductivity of Crystallized 

 Selenium, by MM. Bellati and E. Lusana . '. 324 



NUMBER CLVL— MAT. 



Mr. T. P. Dale on the Numerical Relation between the Index 

 of Refraction and the Wave-length within a Refractive 

 Medium, and on the Limit of Refraction 325 



Mr. T. M. Reade on Tidal Action as au Agent of Geological 

 Change 338 



Dr. A. Griinwald on Mathematical Spectral Analysis of Mag- 

 nesium and Carbon -'MM 



Mr. L. Bell on the Absolute Wave-length of Light, -Part 11. 350 



Mr. H. Tomlinson on the Temperature at which Nickel begins 

 to lose suddenly its Magnetic Properties 372 



Mr. O. Heaviside on Electromagnetic Waves, especially in 

 relation to the Vorticity of the Impressed Forces ; and the 

 Forced Vibrations of Electromagnetic Systems 379 



Mr. J. Parker on the Thermodynamics of Cryohydrates .... 4U0 



