THE

LONDON, EDINBURGH, AND DUBLIN

=

PHILOSOPHICAL MAGAZINE

AND

JOURNAL OF SCIENCE.

CONDUCTED BY

SIR OLIVER JOSEPH LODGE, D.Sc., LL.D., F.R.S.
SIR JOSEPH JOHN THOMSON, O.M., M.A., Sc.D., LL.D., F.R.S
JOHN JOLY, M.A., D.Sc., F.R.S., F.G.S.
RICHARD TAUNTON FRANCIS, F.R.S.E.

AND

WILLIAM FRANCIS, F.L.S.

Nec aranearum sane textus ideo melior quia ex se fila gignunt, nec noster
vilior quia ex alienis libamus ut apes." JUST. LIPS. Polit. lib. i. cap. 1. Not.

VOL. I.-SEVENTH SERIES.

JANUARY-JUNE 1926.

LONDON:

TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET.

SOLD BY SMITH AND SON, GLASGOW ;— HODges, figgis, aND CO., DUBLIN ;—
AND VEUVE J. BOYVEAU, PARIS.

"Meditationis est perscrutari occulta; contemplationis est adm perspicua.... Admiratio generat quæstionem, quæstio investigation investigatio inventionem."-Hugo de S. Victore.

faxon

CONTENTS OF VOL. I.

(SEVENTH SERIES).

NUMBER I.-JANUARY 1926.

Dr. J. Chadwick and Mr. K. G. Emeléus on the d-Rays produced

by a-Particles in Different Gases. (Plates I. & II.)....

Prof. W. M. Thornton on Models of Electron Structure, Quantum

Action, and the Gravitational Field

Dr. H. Rinde on a Method for Determination of the Adsorption

of Ions on Colloidal Particles by means of Donnan's Membrane

Equilibrium Theory ...

Mr. M. H. Belz on the Distribution of Energy in the Continuous

X-ray Spectrum

Page

1

13 ✓

32

50

Prof. H. T. H. Piaggio and Mr. J. Critchlow on a supposed Rela-

tivity Method of Determining the Size of a Gravitating Particle.. 67

Messrs. R. V. Southwell and H. J. Gough on the Concentration of

Stress in the Neighbourhood of a Small Spherical Flaw; and

on the Propagation of Fatigue Fractures in Statistically Iso-

tropic" Materials

66

Dr. R. D. Rusk on the Absorption of Hydrogen in Potassium

Vapour Ares. ....

71

97

Mr. H. Rowe on the Adsorption of Gases by Activated Charcoal

at Very Low Pressures.-I. At Air Temperature

109

Dr. E. E. Witmer on Fraunhofer Diffraction Phenomena for a

General Polygonal Aperture. (Plate III.)...

132

139

... 219

Pro, H. R. Hassé on Langevin's Theory of Ionic Mobility.

Prof. C. G. Darwin on Mechanical Models for the Zeeman Effect .. 161

Dr. D. M. Dennison on the Analysis of Certain Molecular Spectra.. 195

Prof. E. F. Burton on the Relation between Temperature and Mini-
mum Sparking Potential

Mr. G. L. Addenbrooke on the Non-Metallic Elements. Connexions

between their Dielectric and other Physical Properties.-Part II. 225

Prof. A. J. Sutton Pippard and Mr. G. H. W. Clifford on an

Experimental Investigation of the Applicability of Saint-Venant's

Principle to the case of Frameworks having Redundant Bracing

Members

243

254

Prof. A. J. Sutton Pippard on the Effect of Curved Members upon

the Elastic Properties of a Framework ....

Mrs. T. Ehrenfest-Afanassjewa on Dimensional Analysis viewed

from the Standpoint of the Theory of Similitudes

Mr. H. E. H. Wrinch and Dr. D. M. Wrinch on the Roots of Hyper-

geometric Functions with a numerator and four denominators... 272

Mr. J. T. Combridge on the Field of a Thick Spherical Shell on

Einstein's Theory of Relativity

257

276

Prof. M. Saha and Mr. R. Sur on the Absolute Value of Entropy.. 279