Vol. 50. DECEMBER 1875. No. 333. 



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. 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° 333.— DECEMBER 1875. *)\ 



WITH TWO PLATES, 

 Illustrative of Mr. Gr. Darwin's Paper on Maps of the World, and 

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



With this, the regular Number for December 1875, is published, and 

 should be delivered to Subscribers, the Supplement (No. 334) to 

 Vol. L., containing papers by Mr. R.H.M.Bosanquet, Mr.W. H.Wa- 

 lenn, Prof. R. Bunsen, Mr. J. W. L. G-laisher, Mr. W. Weston, 

 Prof. Chalets, together with Proceedings of the Royal Society, Geolo- 

 gical Society, Intelligence and Miscellaneous Articles, and the Title-page, 

 Table of Contents, and Index to Vol. L. 



LONDON: 



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

 Printers and Publishers td the University of London. 

 Sold by Longmans, Grreen, Reader and Dyer ; 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, G-lasgow : — Hodges, Foster, and Co., Dublin: — Putnam, 

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



