Vol.4. AUGUST 1877. No. 23. 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AND 



JOURNAL OF SCIENCE. 



Being a Continuation of TillocKs ^Philosophical Magazine, 

 Nicholson^ s 'Journal^ and Thomsons '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. 



FIFTH SERIES, ' , 



N° 23.— AUGUST 1877. ■ '^''^' 



WITH TWO PLATES, 



Illustrative of Mr. W. Bailt's Paper on a New Automatic Motion for 

 the Spectroscope, and Professors W. E. Ayeton- and J. Peeet's on 

 Ice as an Electrolyte. 



LONDON: 



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

 Printers and Publishers to the University of London. 

 Sold by Longmans, G-reen, Evader and Dyer j Kent and Co. ; Simpkin, Marshall and 

 Co. ; and Whittaker and Co. ;— and by A. and 0. Black, and Thomas Clark, Edin- 

 burgh ; Smith and Son, G-lasgow : — ^Hodges, Foster, and Co., DubUn ; — Putnam, 

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



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