CONTENTS OF VOL. XXVII.— SIXTH SERIES. Vll 



NUMBER CLXL— MAY. 



Page 



Sir J. J. Thomson on the Forces between Atoms and 

 Chemical Affinity ; . 757 



Prof. J, S. TowDsend and Mr. P. J. Edmunds on the Dis- 

 charge of Electricity from Cylinders and Points . . e 789 



Mr. Harold Smith on the Spectroscopy of the Electric Brush 

 Discharge in "Weak Acids and Solutions. (Plate XL) . . 801 



Mr. E. Marsden on the Passage of a Particles through 

 Hydrogen 824 



Miss Margaret B. Moir on the Magnetic Properties of a 

 Graded Series of Chrome Steels at Ordinary and Low 

 Temperatures 830 



Dr. C. V. Burton : An Experiment indicating that Matter 

 takes up no Rooin in the ^Ether 843 



Sir Ernest Rutherford and Dr. E. N. da C. Andrade on the 

 "Wave-Length of the Soft y Rays from Radium B. 

 (Plate XII.) 854 



Dr. E. N. da C. Andrade on Regular Surface Markings in 

 Stretched Wires of Soft Metals. (Plate XIII.) 869 



Prof. H. L. Callendar on Thermodynamics of Radiation .... 870 



Prof. W. H. Bragg on the Intensity of Reflexion of X Rays 

 by Crystals 881 



Prot. R. W. Wood and Mr. G. A. Hemsalech on the Fluor- 

 escence of Gases excited by Ultra-Schumann Waves. 

 (Plates XIY. & XV.) 899 



Dr. Manne Siegbahn on the Use of the Telephone as an 

 Oscillograph. (Plate XYI.) 909 



Intelligence and Miscellaneous Articles : — 



John Henry Poynting 914 



NUMBER CLXIL— JUNE. 



Dr. R. D. Kleeman on the Disintegration of an Ion Cluster 

 in a Gas under the Influence of an Electric Eield 917 



Dr. S. A. Shorter : Contribution to the Therm odynamical 



Theory of Ternary Mixtures 942 



Mr. S. Smith on the Initial Stages of Ionization by 

 Collision 963 



Mr. Gervaise Le Bas on the Theory of Molecular Volumes. — 

 Part III 976 



Dr. G. A. Shakespear on some Modifications in an ordinary 

 Balance which conduce to ease and quickness of weighing. 990 



Mr. G. H. Livens on a Theory of the Rotational Optical 

 Activity in Isotropic Media 994 



Prof. R. W. Wood and M. G. Riband on the Magneto- 

 optics of Iodine Vapour 1009 



Prof. R. W. Wood and M. L. Dunoyer on the Separate 

 Excitation of the Centres of Emission of the D Lines of 

 Sodium. (Plate XVII.) 1013 



