r ol. 13. JANUARY 1882. No. 78. 



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



THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE, 



AST) 



JOUENAL OF SCIENCE. 



Being a Continuation of TillocKs 'Philosophical Magazine? 

 Nicholson's 'Journal? and Thomson's 'Annals of Philosophy.'' 



CONDUCTED BY 



SIB, ROBERT KANE, LL.D. F.R.S. M.R.LA. 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° 78.— JANUARY 1882, 



WITH TWO PLATES. 



Illustrative of Mr. L. Weight's Paper on some Spiral Figures observable 

 in Crystals, illustrating the Eelation of their Optic Axes, and Mr. T. 

 Batxey's on the Connexion between the Atomic Weight and the Che- 

 mical and Physical Properties of Elements. 



LONDON: 



FEINTED BY TAYEOB, AND FRANCIS, BED DION COTTBT, FLEET STHEET, 



Sold by Longmans, Green, 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, Glasgow : — Hodges, Foster and Co., Dublin: — Putnam, 

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



