VI CONTENTS OF VOL. XXXIV. SIXTH SERIES. 



NUMBEE CCIV.— DECEMBEE. 



Prof. Frank Horton on the Application of Thermionic Currents 

 to the Study of Ionization by Collision 461 



Dr. H. S. Allen on Atomic Frequency and Atomic Number. — 

 Frequency Formulae with Empirical Constants 478 



Dr. H. 8. Allen on Electronic Frequency and Atomic Number 488 



Mr. T. Chaundy on a Method of Line-Coordinates for Investi- 

 gating the Aberrations of a Symmetrical Optical System. . 496 



Prof. H. C. Plummer on the Action of Coupled Circuits and 

 Mechanical Analogies 510 



Sir Oliver Lodge on Astronomical Consequences of the Elec- 

 trical Theory of Matter 517 



Dr. S. A. Shorter and Dr. F. Tinker on the Kinetic Theory 

 of the Ideal Dilute Solution 521 



Proceedings of the Greological Society : — 



Dr. E. J. G-arwood and Miss E. Goodyear on the Geology 

 of the OJd Eadnor District, with special reference to an 

 Algal Development in the Woolhope Limestone .... 528 



Index , 529 



