IV CONTENTS OF VOL. XXV. SIXTH SERIES. 



Page 

 Mr. D. C. H. Florance : A Study of the Ionization produced 



by ft and y Rays at High Pressures (Plate I.) 172 



Messrs. E. Marsden and H. Richardson on the Retardation 



of a Particles by Metals 184 



Mr. J. Chadwick on the Excitation of y Pays by a Rays. . . . 193 

 Notices respecting New Books : — 



Prof. Dr. Otto Sackur's Lehrbuch der Thermochemie und 



Thermodynamik 197 



Proceedings of the Geological Society : — 



Mr. H. H. Thomas and Prof. 6. T. Jones on the Pre- 

 Cambrian and Cambrian Rocks of Brawdy, Hayscastle, 



and Brimaston (Pembrokeshire) 197 



Prof. 0. T. Jones on the Geological Structure of Central 



"Wales and the Adjoining Region 198 



Mr. P. Lake and Prof. S. H. Reynolds on the Geology 



of Mynydd Gader, Dolgelly 199 



Intelligence and Miscellaneous Articles: — 



Correction to paper on " The Relation of Airy's Integral 

 to the Bessel Functions," bv Prof. J. W. Nicholson. . 200 



NUMBER CXLVL— FEBRUARY. 



Mr. C. G. Darwin on Some Orbits of an Electron 201 



Mr. E. H. Parker on some Properties of Red Vulcanized 



Fibre- 210 



Mr. E. Jacot on a Relation between Ionization by Cathode 



Rays and certain Chemical Effects 215 



Mr. D. L. Webster on the Theory of the Scattering of 



Rontgen Radiation 234 



Mr. Norman Shaw on the Charged Surface Layers in Contact 



Potential Phenomena between Metals . 241 



Mr. W. T. David on Thermal Radiation from Hot Gases . . 256 

 Mr. J. H. T. Roberts on the Disintegration of Metals at High 



Temperatures. Condensation Nuclei from Hot Wires. 



(Plate II.) 270 



Dr. C. G. Barkla and Mr. G. H. Marty n on the Photographic 



Effect of X-Kays and X-Ray Spectra 296 



Prof. J. Joly on the Apophorometer ... 301 



Prof. E. Rutherford and Mr. H. Robinson on the Heating 



Effect of Radium and its Emanation 312 



Mr. C. F. Hogley on the Solubility of the Active Deposit of 



Thorium in Various Solvents 330 



Dr. A. LI. Hughes on the Photo-Electric Effect in some 



Compounds 332 



