h 31. FEBRUARY 1866. No. 207, 



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THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



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

 Nicholson's i Journal' and Thomson's 'Annals of Philosophy ' 



CONDUCTED ttV 



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

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

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



FOURTH SERIES, 



N° 207.— FEBRUARY 1866. 



WITH TWO PLATES, 



Illustrative of Sir David Brewster's Paper on the Bands formed by 

 the Superposition of Paragenic Spectra produced by the Grooved 

 Surfaces of Glass and Steel. 



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