THE 



PHILOSOPHICAL MAGAZINE, 



OR 



ANNALS 



OF 



CHEMISTRY, MATHEMATICS, ASTRONOMY, 



NATURAL HISTORY, AND 



GENERAL SCIENCE. 



BV 



RICHARD TAYLOR, F.S.A. L.S. G.S. M. Astr. S. &c. 



AND 



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



" Nee aranearum sane textus ideo melior quia ex se fila gignunt, nee noster 

 vilior quia ex .ilienis libamus ut apes." Just. Lips. Monit. Polit. lib. i. cap. 1. 



VOL. VIL 



NEW AND UNITED SERIES OF THE PHILOSOPHICAL MAGAZINE 

 AND ANNALS OF PHILOSOPHY. 



JANUARY-JUNE, 1830. 



LONDON: 



PRINTED BY RICHARD TAYLOR, RED LION COURT, FLEET STREET, 



Printer to the Universiti/ of London. 



SOLD BY LONGMAN, REES, OBME, BROWN, AND GREEN; CADELL ; BALDWIN 

 AND CRADOCK; SHERWOOD, GILBERT, AND PII'ER ; SIMPKIN 



AND MARSHAL!. ; UNDERWOOD; AND S. HIOHLEY, LONDON : 



AND BY ADAM BLACK, EDINBURGH; SMITH AND SON, 

 GLASGOW ; AND HODGES AND M'ARTHUR, DUBLIN. 



Sir, ■ ■ •— ' ,i.A' 



