T H E 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



CONDUCTED BY 



SIR DAVID BREWSTER, K.H. LL.D. F.R.S.L.&E. Sec. 

 RICHARD TAYLOR, F.L.S. G.S. Astr.S. Nat.H.Mosc.&c 

 RICHARD PHILLIPS, F.R.S.L.&E. F.G.S. &c. 

 SIR ROBERT KANE, M.D. M.R.I.A, 



" Nee aranearum sane textus ideo nielior quia ex se fila gignunt, iicc itoster 

 vilior quia ex aiienis libamus ut apes." Just. Lips. Polit. lib. i. cap. 1 . Not. 



VOL. XXX. 



NEW AND UNITED SERIES OF THE PHILOSOPHICAL MAGAZINE, 

 ANNALS OF PHILOSOPHY, AND JOURNAL OF SCIENCE. 



JANUARY— JUNE, 1847. 



LONDON: 



IlICHAllD AND JOHN E. TAYLOR, RED LION ( OIJRT, FLEET STREET, 



Priii/crs and Publishers to the University of London; 



SOI.U BY LONGMAN, BROWS', GREEN, AND LONGMANS; SIMPKIN, MARSHALL 

 AND CO.; S. HIGHLEY ; WIIITTAKER AND CO.; AND SHERWOOD, 



GILBERT, AND PIPER, LONDON : BY ADAM AND CHARLES 



ni.ACK, AND THOMAS CLARK, EDINBURGH ; SMITH AND SON, 



<;l.ASC.OW ; HODGES ANU SMllH, DIJIILIN ; AND 



WILEY AND PUINAM, NEW YORK. 



