THE 

 LONDON, EDINBURGH, and DUBLIN 



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PHILOSOPHICAL MAGAZINE 



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JOURNAL OF SCIENCE. 



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. 



11 Nec aranearum sane textus ideo melior quia ex se fila gignunt, nee noster 

 vilior quia ex alienis libamus ut apes." Just. Lips. Polil. lib. i. cap. 1. Not. 



VOL. XX.— FIFTH SERIES. 

 JULY— DECEMBER 1885. 



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