﻿r ol. 37. JUNE 1869. No. 251 



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,' 

 Nicholsons 'Journal? and Thomson's 'Annals of Philosophy? 



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

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



FOURTH SERIES. 



N° 251.— JUNE 1869. 



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