IT CONTENTS OF VOL. X. SIXTH SERIES. 



Page 

 Mr. W. C. Clinton on the Voltage Ratios of an Inverted 



Rotary Converter ] 60 



Prof. E. Rutherford on some Properties of the a Rays from 



Radium 1 63 



Dr. O. W. Richardson on the Structure of Ions formed in 



Gases at High Pressures 177 



Mr. R. J. Sowter on Ellipsoidal Lenses 180 



Mr. W. A. D. Rudge on the Properties of Radium in Minute 



Quantities 183 



Notices respecting New Books : — 



Miss Ida Freund's The Study of Chemical Composition. .. 184 

 Dr. G. Jaumann's Die Grundlagen der Bewegungslehre. 185 

 Messrs. H. Le Chatelier and O. Boudouard's High-Tem- 

 perature Measurements 185 



Bulletin of the Bureau of Standards 186 



Dr. A. N. Meldrum's Avogadro and Dalton 186 



Dr. P.M. Perkin's Practical Methods of Electro-Chemistry. 186 

 Proceedings of the Geological Society : — 



Messrs. H. J. 0. White and L. Treacher on the Age and 



Relations of the Phosphatic Chalk of Taplow 188 



Mr. R. H. Rastall on the Blea-Wyke Beds and the Dogger 



in North-East Yorkshire 189 



Mr. G. P. J. Preumont on the Geological Aspect of some 

 of the North-Eastern Territories of the Congo Pree 



State 190 



Dr. P. Marshall on the Geology of Duuedin (N. Zealand). 191 

 Mr. T. F. Sibly on the Carboniferous Limestone of the 

 Weston-super-Mare District 192 



NUMBER LVL— AUGUST. 



Prof. E. Rutherford on the Charge carried by the a. and fl Rays 



of Radium 193 



Dr. J. A. Fleming on the Ratio between the Mean Spherical 



and the Mean Horizontal Candle-Power of Incandescent 



Electric Lamps 208 



Mr. G. B. Dyke on the Flux of Light from the Electric Arc 



with Varying Power-Supply (Plate II.) 216 



Mr. J. W. Nicholson on Electrical Vibrations between Confocal 



Elliptic Cylinders, with special reference to Short Waves . . 225 

 Mr. A. A. Robb on the Conduction of Electricity through 



Gases between Parallel Plates 237 



Dr. O. W. Richardson on the Rate of Recombination of Ions 



in Gases 242 



