Vol. 21. JUNE 1886. No. 133 



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



THE 

 LONDON, EDINBUKGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AJ5TD 



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.8. 

 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° 133.— JUNE 1886. 



WITH ONE PLATE. 



Illustrative of Prof. Thompson's Notes on some New Polarizing Prisms. 



LONDON: 



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