THE 

 LONDON, EDINBURGH, asd DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



CONDUCTED BY 



SIR ROBERT KANE, LL.D. F.R.S. M.R.I.A. F.C.S. 

 SIR WILLIAM THOMSON, Knt. LL.D. F.R.S. &c. 



AND 



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. XIV.— FIFTH SERIES. 

 JULY— DECEMBER 1882. 



DEC 16 ._ 



TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET. 



SOLD BY LONGMANS, GREEN, READER, AND DYER; KENT AND CO. ; SIMPKIN, MARSHALL, 



AND CO. ; AND WIIITTAKER AND CO. ; AND BY ADAM AND CHARLES BLACK, 



AND THOMAS CLARK, EDINBURGH; SMITH AND SON, GLASGOW; 



HODGES, FOSTER, AND CO., DUBLIN; PUTNAM, NEW 



YORK; — AND ASHER AND CO., BERLIN. 



