THE 
LONDON, EDINBURGH, ann DUBLIN 
PHILOSOPHICAL MAGAZINE 
AND 
JOURNAL OF SCIENCE. 
CONDUCTED BY 
SIR DAVID BREWSTER, K.H. LL.D. F.R.S.L. & E. &e. 
SIR ROBERT KANE, M.D., F.R.S., M.R.LA. 
WILLIAM FRANCIS, Pu.D. F.L.S. F.R.AS. F.C.S. 
JOHN TYNDALL, F.R.S. &e. 
“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. XIX.—FOURTH SERIES. 
JANUARY—JUNE, 1860. 
LONDON. 
TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET, 
Printers and Publishers to the University of London ; 
SOLD BY LONGMAN, GREEN, LONGMANS, AND ROBERTS ; SIMPKIN, MARSHALL 
AND CO.; WHITTAKER AND CO.; AND PIPER AND CO., LONDON :—— 
BY ADAM AND CHARLES BLACK, AND THOMAS CLARK, 
EDINBURGH; SMITH AND SON, GLASGOW ; HODGES 
AND SMITH, DUBLIN ; AND PUTNAM, 
NEW YORK. 
