﻿Vol. 41. MAY 187L 



No. 274. 



Published the First Day of every Month—Price 2s. 6d. 



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 BY 



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



AND 



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



FOURTH SERIES. 



N° 274.— MAY 1871. 



LO NDON: 



PBINTED BY TAYLOB AND FBANCIS, BED LION COUBT, FLEET STBEET, 



Printers and Publishers to the University of London. 



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