﻿THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



CONDUCTED BY 



SIR OLIVER JOSEPH LODGE, D.Sc, LL.D., F.R.B. 



SIR JOSEPH JOHN THOMSON, O.M., M.A., So.D., LL.D., F.R.S. 



JOHN JOLY, M.A., D.Sc, F.R.S., F.G.S. 



RICHARD TAUNTON FRANCIS 



AND 



WILLIAM FRANCIS, F.L.S. 



"Nee araisearuni sane textus ideo melior quia ex se ftla gigiiunt, nee noster 

 ilior quia ^x alienis libamus ut apes." Just. Lips. Polit. lib. L cap. 1. Not. 



VOL. XLIV.— SIXTH SERIES. 

 JULY— DECEMBER 1922. 



LONDON-. 

 TAYLOR AND FRANCIS, RED LION COURT. FLEET STREET. 



SOLD BY SMITH AND SON, GLASGOW ;— HODGES, FIGGIS, AND CO., DUBLIN ; - 

 AND VEUVE J. BOYVEAU, PAKI C , 



