Vol. 32. DECEMBER 1866. No. 218. 



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, 3 

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



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SIR DAVID BREWSTER, K.H. LL.D. F.R.S. L.&E &c 

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



FOURTH SERIES. 



N° 218.— DECEMBER 1866. 



WITH A PLATE, 

 Illustrative of Mr. R. Templeton's Paper on the Index of Refraction 

 of the Lens. 



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