Vol. 57. 



March 1821. 



No. 275. 



Published the Last Day of eveinj Month, 

 [PRICE 2s. ed.] 



THE 



PHILOSOPHICAL MAGAZINE 

 AND JOURNAL: 



COMPEBHBNDINO 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 



GEOLOGY, 



AGRICULTURE, 



MANUFACTURES AND COMMERCE. 



NUMBER CCLXXV. 

 For MARCH 1821. 



BY ALEXANDER TILLOCH, 



M.R.I.A. M.G.S. M.R.A.S. MUNICH, F.S.A. EDIN. AND PERTH, 

 M.S.E.I.N. OF FRANCE, &C. &C. &C. 



— - 1 ""^ 



LONDON: 



PRINTED BY RICHARD AND ARTHUR TAYLOR, SHOF.-LANE : 



, And sold by Cade.l and Davies ; Loncma., Hurst, Rees 

 ■ OuME,& Brown; H.GHi,Ev;SHERWOODandCo.,^HARD.NG, 

 Underwood; S.MPK.NandMARSHALL;London:CoNSTABLEl 



and Co. Edinburgh: Brash and Reid ; ^-^^^^^^^^ ^ '"" 

 MAN, Glasgow: and Gilbert unci Hodges, Dublin. 



