CONTENTS OF VOL. V. SIXTH SERIES. Vll 



Page 

 Dr. E. T. Glazebrook : Theoretical Optics since 1840. — A 



Survey 537 



Dr. E. J. Mills on the Numerics of the Elements.— Part III. 543 

 Mr. J. J. E. Durack on the Specific Ionization produced by the 



Corpuscles given out by Radium 550 



Prof. E. Rutherford and Mr. F. Soddy on Condensation of 



the Radioactive Emanations. (Plate XIV.) 561 



Prof. E. Rutherford and Mr. F. Soddy on Radioactive Change. 576 

 Mr. J. Brown on Removal of the Voltaic Potential-Difference 



by Heating in Oil 591 



Notices respecting New Books : — 



Dr. W. L. Hooper and Mr. R. T. Wells's Electrical 



Problems for Engineering Students 595 



Intelligence and Miscellaneous Articles : — 



On the Heat evolved when a Liquid is brought into Con- 

 tact with a finely-divided Solid, by Tito Martini .... 595 



NUMBER XXX.— JUNE. 



Mr. J. H. Jeans on the Kinetic Theory of Gases developed 

 from a New Standpoint 597 



Prof. A. Battelli and Mr. L. Magri on Oscillatory Discharges. 

 (Plate XV.) 620 



Prof. W. B. Morton on the Connexion between Speed of 

 Propagation and Attenuation of Electric Waves along 

 Parallel Wires 643 



Mr. W. H. Derrimau on an Oscillating Table for Deter- 

 mining Moments of Inertia 648 



Messrs. K. Honda and S. Shimizu on the Wiedemann Effect 

 in Ferromagnetic Substances. (Plate XVI.) 650 



Prof. Karl Pearson on a General Theory of the Method of 

 False Position 658 



Dr. R. A. Lehfeldt on a Potentiometer for Thermocouple 

 Measurements 668 



Dr. R. A. Lehfeldt on a Resistance Comparator 672 



Prof. S. P. Langley on " Good Seeing." (Plate XVII.) .... 674 



Lord Rayleigh on the Proportion of Argon in the Vapour 

 rising from Liquid Air 677 



Hon. R. J. Strutt on Radioactivity of Ordinary Materials . . 6S0 



Mr. C, G. Barkla on Secondary Radiation from Gases subject 

 to X-Rays 685 



Prof. J. S. Townsend on the Specific Ionization produced by 

 Corpuscles of Radium 60S 



Messrs. J. C. McLennan and E. F. Burton : Experiments 

 on the Electrical Conductivity of Atmospheric Air 699 



Notices respecting New Books : — 



Prof. S. Arrhenius's Text-Book of Electrochemistry . . 708 



Prof. J. M. Pernter's Meteorlogische Optik . . . . . 709 



Mr. J. Castell-Evans's Physico-Chemieal Tables 710 



Index 711 



