CONTENTS OF VOL. XXI. SIXTH SERIES. Vll 



Page 

 Prof. E. Rutherford on the Scattering of ex and [3 Particles by 



Matter and the Structure of the Atom 069 



Profs. H. Rubens and O. von Baeyer on Extremely Long 



Waves emitted by the Quartz Mercury Lamp 689 



Proceedings of the Geological Society : — 



Mr. T. O. Bosworth on the Keuper Marls around Charn- 

 wood Eorest 695 



NUMBER CXXVL— JUNE. 



Lord Rayleigh on the Motion of Solid Bodies through Viscous 



Liquid 697 



Prof. H. A. Wilson on the Velocity of the Ions of Alkali 



Salt Vapours in Flaines 711 



Prof. H. A. Wilson on the Number of Electrons in the Atom 718 

 Dr. R. W. Boyle on the Behaviour of Radium Emanation at 



Low Temperatures 722 



Dr. W. E. Gr. Svvann on the Longitudinal and Transverse 



Mass of an Electron , . 733 



Mr. John R. Airey on the Oscillations of Chains and their 



Relation to Bessel and Neumann Functions 736 



Prof. James E. Ives : An Approximate Theory of an Elastic 



String vibrating, in its fundamental mode, in a Viscous 



Medium 742 



Mr. H. Bateman on some Problems in the Theory of 



Probability 745 



Prof. R. A. Millikan and Mr. Harvey Fletcher on the Question 



of Valency in Gaseous Ionization 753 



Mr. Arnold L. Fletcher on the Radioactivity of some Igneous 



Rocks from Antarctic Regions 770 



Mr. Andrew Stephenson on Water Waves as Asymmetric 



Oscillations, and on the Stability of Free Wave-Trains . . 773 



Index 77i> 



