THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



CONDUCTED BY 



LORD KELVIN, LL.D. F.R.S. &c. 

 GEORGE FRANCIS FITZGERALD, M.A. Sc.D. F.R.S. 



WILLIAM FRANCIS, Ph.D. F.L.S. F.R.A.S. F.C.S. 



" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster 

 vilior quia ex alienis libamus ut apes." Just. Lips. Polit. lib. i. cap. 1. Not. 



VOL. XLL— FIFTH SERIES. 

 JANUARY— JUNE 1896. 



LONDON: 

 TAYLOR AND FRANCIS, EED LION COURT, FLEET STREET. 



SOLD BY SIMPKIN, MARSHALL, HAMILTON, KENT, AND CO., LD.J WniTTAKER AND CO. J 



AND BY ADAM AND CHARLES BLACK ; T. AND T. CLARK, EDINBURGH ; 



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



PUTNAM, NEW YORK;— VEUVE J. BOYVEAU, PARIS J 



AND ASnER AND CO., BERLIN. 



