SUPPLEMENTARY NUMBER. 



Vol. 50. No. 334 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOUKNAL 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. F.C.S. 

 SIR WILLIAM THOMSON, Knt. LL.D. F.R.S. &c. 



AND 



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



FOURTH SERIES. 



N° 334.— SUPPLEMENT. DECEMBER 1875. 



WITH THREE PLATES, 



Illustrative of Prof. R. Bunsen's Spectral- Analytical Researches. 



NOTICE. 



As the present Number will complete the 50th Volume of the present 

 Series of the Philosophical Magazine, and the type will be entirely 

 renewed, it has been deemed advisable to commence the new year with 

 a Fifth Series, the First Number of which will be published on the 1st 

 January, 1876. 



LONDON: 



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



Printers and Publishers to the University of London. 

 Sold by Longmans, Green, Reader and Dyer j Kent and Co. ; Simpkin, Marshall and 

 Co. ; and Whittaker and Co. ; — and by A. and C. Black, and Thomas Clark, Edin- 

 burgh ; Smith and Son, Q-lasgow : — Hodges, Foster, and Co., Dublin: — Putnam, 

 New York : — and Asher and Co., Berlin. 



