THE 



PHILOSOPHICAL MAGAZINE: 



COMPREHENDING 



THE VARIOUS BRANCHES OF SCIENCE, 



THE LIBERAL AND FINE ARTS, 

 AGRICULTURE, MANUFACTURES, 



AND 



COMMERCE. 



BY ALEXANDER TILLOCH, 



MEMBER OF THE LONDON PHILOSOPHICAL SOCiETY, ETC. ETC. -^ 



«« Nee aranearum fane textus ideo raelior, quia ex fe fila gignunt, Necnofter 

 •ilior quia ex alienis libamus ut apes." Just. Lips. Monii. PoUt. lib. i. cap. i. 



VOL. XII. 



LONDON: 



Printed for Alexander Tilloch; 



And Sold by Meffrs. Richardson, Cornhill ; Cadell and Davies, 



Strand; DeuRniT, Piccadilly; Mo r ray and High ley, No. 32, 



fleet-ftreet ; Symonds, Pater-notler Row ; Bell, No. 148, 



Oxford-ftreet ; Vernor nnd Hood, Poultry ; Harcinc, 



Ko. 36, St. James's-ftreet; Bell .-iiid Bradfutk, 



Kdinbuigli; Brash and Reid, Gl.iigow; 



and W. Gilbert, Dublih. 



IfVilii and Tj^lir, FrinUrt, Chantry Lint.'] 



