CONTENTS OF VOL. VIII.—SIXTH SERIES. Vv 
NUMBER XLV.—SEPTEMBER. 
Page 
Prof. R. W. Wood on a Quantitative Determination of the ; 
Anomalous Dispersion of Sodium Vapour in the Visible 
and Ultra-Violet Regions. (Plates XXII.) .......... 293 
Prof. R. W. Wood on the Achromatization of Approximately 
Monochromatic Interference Fringes by a Highly Dis- 
persive Medium, and the consequent Increase in the 
Allowable Path-difference. With a Note by Lord Rayleigh. 324 
Prof. J. J. Thomson on Momentum in the Electric Field .. 331 
Mr. R. K. McClung on the Relative Amount of Ionization 
produced in Gases by Rintgen Rays of Different Types .. 357 
Miss H. Brooks on the Decay of the Excited Radioactivity 
from Thorium, ‘Radium; and Actinium *.-....°.°. 0.7... 2... 373 
Prot. G: A. Schott on he Kinetics of a System of Particles 
illustrating the Line and Band Spectrum ........... 384 
Prof. Clarence A. Skinner on the Relation of Electrode Fall 
in Gases to the Contact Potential Series .............. 387 
Dr. O. W. Richardson on the Effect of a Luminous Discharge 
on the: Ionization produced by Hot Platinum in Gases at 
(i LEAS ST e)c) SNC A enact oe ae rae 400 
Prof. J. Trowbridge and Mr. W. Rollins on Radium and 
Beebe PNCOLY . 15. e/a ine -nece je ace dw aoe teamlne nes 410 
Proceedings of the Geological Society :— 
Prof. G. De Lorenzo on the History of Volcanic Action 
memes Ee hieerean: Mreldsintit..$22 6320220. uo Les vee 413 
Mr. A. J. R. Atkin on the Genesis of the Gold-Deposits 
faeeankerville (be Columblay -2.f00 0 ee eee OO Al5 
Mr. H. H. Arnold-Bemrose on some Quartzite-Dykes 
- in Mountain-Limestone near Snelston (Derbyshire) .. 415 
Dr. Du Riche Preller on Phenomena bearing upon the 
meron tie Wake o: Geneva. Fo... eee ee) cen g: 416 
NUMBER XLVI.—OCTOBER. 
Prof. J. A. Fleming on the Propagation of. Electric Waves 
along Spiral Wires, and on an Appliance for Measuring 
the Length of Waves used in Wireless Telegrapby. (Plate 
ea DN em eet See sie ek ge wc Shh el AML ES Snaly ule 5 34 417 
Mr. A. E. Garrett and Dr. R. 8. Willows on Chemical 
Dissociation and Electrical Conductivity .............. 437 
Lord Kelvin on the Front and Rear of a Free Procession of 
Vian cammembcep,. Water it see Ghid. oes hea eae se alee 454 
Mr. C. E. Haselfoot and the Rev. P. J. Kirkby on the 
Electrical Effects produced by the Explosion of Hydregen 
mnie apres VSPA derek ithe SoA Woe a o's Va Sath. 4 8 471 
Lord Rayleigh on the Open Organ-Pipe Problem in Two 
PDE bene Wisely ey 8 Lean Sow ha al he alah dte sa 481 
