﻿VoL37 - MARCH 1869. 



No. 248. 



>iian Institution. 



WILLIAM WESLEY, 



fcoofcsoUcr anu tfublisfjcr, 

 81, Fleet Street, London. 



the First Day of every Month.— Price 2s. Qd. 



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of Tilloch's 'Philosophical Magazine,' 

 Nicholson's 'Journal,' and Thomson's < Annals of Philosophy.' 



CONDUCTED HV 



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

 AUGUSTUS MATTHIESSEN, Ph.D. F.R.S. F.C.S. 



AND 



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



FOURTH SERIES. 



N° 248.— MARCH 1869. 



LO ND O N: 



PRINTED BY TAYLOR AND FRANCIS, RED LION COURT, FLEET STREET 

 Printers and Publishers to the University of London. 



