﻿CONTENTS OF VOL. XXIX. SIXTH SERIES. Vll 



Page 



NUMBER CLXXIV.— JUNE. 



Prof. II. Lamb and Miss L. Swain on a Tidal Problem .... 737 

 Mr. W. Barlow and Prof. W. J. Pope on Topic Parameters 



and Morphotropic Relationships 745 



Dr. A. C. Crehore on the Construction of Cubic Crystals 



with Theoretical Atoms. (Plate XI.) 750 



Dr. W. Marshall Watts on the Principal Series in the 



Spectra of the Alkali Metals 775 



Dr. Norman Campbell on Ionization by Positive Kays .... 783 

 Dr. "William Wilson on the Quantum-Theory of Radiation 



and Line Spectra 795 



Mr. K. K. Smith on Negative Thermionic Currents from 



Tungsten 802 



Dr. I. J. Schwatt on the Higher Derivative of a Function, 



the variable of which is a Function of an independent 



variable 823 



Mr. G. B. Jeffery on Self-Intersecting Lines of Force and 



Equipotential Surfaces 832 



Prof. R. R. Sahni on the Photographic Action of a, ft, and y 



Eays. (Plate XII.) 836 



Proceedings of the Geological Society : — 



Mr. Charles Irving Gardiner on the Silurian Inlier of 



Usk (Monmouthshire) 841 



Mr. Samuel Rennie Haselhurst : Some Observations 

 on Cone-in-Cone Structure and their Relation to its 

 Origin 843 



Index 844 



