Vol. 12. y^ JULY 1881. No. 72. 



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 TillocKs { Philosophical Magazine? 

 Nicholson s Journal? and Thomsons l 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° 72.— JULY 1881. 



WITH A PLATE. 



Illustrative of Prof. J. H. Pointing's Paper on Change of 

 State : Solid -T/iqffflk*..*.,-. — N n m 





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