THE 



PHILOSOPHICAL MAGAZINE 



AJ^JD JOURNAL: 



COM PREHENDING 



THE VARIOUS BRANCHES OF SCIENCE, 

 THE LIBERAL AND FINE ARTS, 



GEOLOGY, 

 AGRICULTURE, 



MANUFACTURES, AND COMMERCE. 



BY ALEXANDER TILLOCH, 



M.R.I.A. M.R A.S. Munich, M.G.S. M.A.S F.S.A. Edin. and Pertu, 

 M.S E.I.N. OF France, Sec. &c. &c. 



" Nee araneanim sane textus ideo melior quia ex se fila gignunt, nee noster vilior qui« 

 ex alienis libamus ut apes," Just. Lips. Monit. Polit. lib, i. cap. 1, 



W't^r-;;^/ VOL. LVIl. 



For JANUARY, FEBRUARY, MARCH, APRIL, MAY, and 

 JUNE, 1821. 



LONDON: 



rRINTKD BY niCHARD AND ARTHUK TAYLOR, SHOE LANB: 

 Aiirf M)l.l by C'ADKi.Lancl Davies; Longman, HiuibT, Rees, Ok.me, and 

 Browm; Hioiilet; Sherwood and Co.; Haudini; ; Under- 

 wood; Simhkin and Maiuhiali., Londmi: Constable 

 and Co. Edinburgh: Urasu and Reid; Duncan 

 and PiNMAN,(;I.isj>ow: and GiLBtliT and 

 Hooul;*, Dublin. 



