VI CONTENTS OF VOL. XXXI. SIXTH SERIES. 



Page 



Prof. G. A. J. Cole on a Composite Gneiss near Barna 

 in the County of G-alway 414 



Prof. S. H. Reynolds on the Igneous Eocks associated 

 with the Carboniferous Limestone of the Bristol 

 District 414 



Messrs. E. H. Eastall and W. H. Wilcockson on the 

 Accessory Minerals of the Granitic Eocks of the 

 English Lake District 415 



Mr. E. P. Mennell on the Eocks of the Lyd Valley, 

 above Lydford (Dartmoor) , 416 



NUMBER CLXXXV.— MAT. 



Prof. E. C. C, Baly and Mr. E. GL Tryhorn : Light Absorption 

 and Fluorescence. — IV. Change in Absorption with Con- 

 centration 417 



Mr. II. F. Biggs on the Energy of the Secondary Beta Eays 



produced by partly-absorbed Gamma Rays 430 



Mr. A, J, Dempster on the Ionization and Dissociation of 



Hydrogen Molecules and the Formation of H 3 438 



Mr. S. Butter worth on the Coefficients of Mutual Induction 



of Eccentric Coils 443 



Mr. S. S. Eichardson : Magnetic Rotary Dispersion in 

 Relation to the Electron Theory. — Part II. The Number 



of Electrons and Additive Relations 454 



Dr. 3. Brocl^tsky and Dr. B. Hodgson on the Absorption of 



Gases in Vacuum-Tubes, and Allied Phenomena 478 



Prof. I. J. Sch watt on the Expansion of a Function 490 



Notices respecting New Books : — 



Prof. Karl Pearson's Tables for Statisticians and Bio- 

 metricians 493 



Proceedings of the Geological Society:- — 



Mr. W. E. Jones on the Origin of the Tin-Ore Deposits 



of the Kinta District, Perak 495 



Intelligence and Miscellaneous Articles: — 



On Mutual- and Self-Inductance Series, by S. Butter- 

 worth . . . . . . 496 



NUMBER CLXXXVL— JUJNE. 



Profs. O. W. Richardson and Charles Sheard : The Variation 

 of the Positive Emission Currents from Hot Platinum with 

 the Applied Potential Difference 497 



