﻿VI CONTENTS OE VOL. XII. SIXTH SERIES. 



Page 

 Prof. E. Rutherford on the Mass and Velocity of the a particles 



expelled from Radium and Actinium. (Plate V.) 348 



Prof. E. Rutherford and Dr. 0. Hahn on the Mass of the 



a particles from Thorium. (Plate V.) 371 



Mr. J. A. Crowther on the Coefficient of Absorption of the 



(3 Rays from Uranium '. 379 



Profs. R. B. Moore and H. Schlundt on some New Methods 



for Separating Uranium X from Uranium 393 



Sir W. Ramsay and Dr. J. F. Spencer on Chemical and 

 Electrical Changes induced by Ultraviolet Light. (Plates 



VI. & VII.) 397 



Prof. E. L. Hancock on the Effect of Combined Stresses on 



the Elastic Properties of Iron and Steel. (Plate VIII.) . . 418 

 Prof. E. L. Hancock on Tests of Metals in Reverse Torsion. 



(Plates IX. & X.) 426 



Notices respecting New Books : — 



Dr. T. Muir's The Theory of Determinants in the 



Historical Order of Development 431 



Mr. T. B. Strong's Lectures on the Method of Science . 431 

 Dr. F. Niethammer's Moteurs a Collecteur a Courants 

 Alternatif s 432 



NUMBER LXXL— NOVEMBER. 



Prof. T. R. Lyle and Mr. J. M. Baldwin : Experiments on 



the Propagation of Longitudinal Waves of Magnetic Elux 



along Iron Wires and Rods , 433 



Mr. A. Campbell on the Use of Chilled Cast Iron for 



Permanent Magnets 468 



Mr. E. E. Burton on the Action of Electrolytes on Colloidal 



Solutions 472 



Prof. R. A. Lehfeldt on the Acceleration of Gravity at 



Johannesburg - 479 



Prof. C. A. Skinner : Comparative Observations on the 



Evolution of Gras from the Cathode in Helium and Argon . 481 

 Lord Rayleigh on the Interference-Rings, described by 



Ilaidinger, observable by means of Plates whose Surfaces 



are absolutely Parallel. (Plate XVI.) 489 



Mr. C. V. Raman on Unsymmetrical Diffraction-bands due 



to a Rectangular Aperture 494 



Mr. L. B. Tuckerman's Remarks on Prof. Jeans's Article 



" On the Thermodynamical Theory of Radiation " 498 



Prof. R. W. Wood on the Fluorescence and Magnetic 



Rotation Spectra of Sodium Vapour, and their Analysis. 



(Plates XI.-XV.) "... 499 



Notices respecting New Books : — 



Prof. J. A. Fleming's The Principles of Electric Wave 

 Telegraphy 525 



