D 



THE 



EDINBURGH ENCYCLOPEDIA; 



CONDUCTED BY 



DAVID BREWSTER, LL.D. 



F. R. S, LOND. AND ED1N. AND M. II. I. A. 



( CIKRKSI'ONDING MEMBER OF THE ROYAL ACADEMY OP SCIENCES OF PARIS, AND OF THE ROYAL ACADEMY OF SCIENCES OF 

 PRUSSIA J MEMBER OF THE ROYAL SWEDISH ACADEMY OF SCIENCES ; OF THE ROYAL SOCIETY OF SCIENCES OF DENMARK ; OF 

 THE ROYAL SOCIETY OF GOTTINGEN, AND OF THE ROYAL ACADEMY OF SCIENCES OF MODENA ; HONORARY ASSOCIATE OF THK 

 ROYAL ACADEMY OF SCIENCES OF LYONS ; ASSOCIATE OF THE SOCIETY OF CIVIL ENGINEERS ; MEMBER OF THE SOCIETY OF THE AN- 

 TIQUARIES OF SCOTLAND; OF THE GEOLOGICAL SOCIETY OF LONDON, AND OF THE ASTRONOMICAL SOCIETY OF LONDON; OF THF. 



UII'RICAN ANTIQUARIAN SOCIETY ; HONORARY MEMBER OF THE LITERARY AND PHILOSOPHICAL SOCIETY OF NEW YORK, OF THK 

 HISTORICAL SOCIETY OF NEW YORK; OF THE LITERARY AND PHILOSOPHICAL SOCIETY OF UTRECHT; OF THE PHILOSOPHICAL 

 SOCIETY OF CAMBRIDGE ; OF THE LITERARY AND ANTIQUARIAN SOCIETY OF PERTH ; O< THE NORTHERN INSTITUTION, AND OF 

 THE ROYAL MEDICAL AND PHYSICAL SOCIETIES OF EDINBURGH; OF THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA; OF 

 THE SOCIETY OF THE FRIENDS OF NATURAL HISTORY OF BERLIN ; OF THE NATURAL HISTORY SOCIETY OF FRANKFORT ; OF THE 

 1'IULOSOPHICAL AND LITERARY SOCIETY OF LEEDS, OF THE ROYAL GEOLOGICAL SOCIETY OF CORNWALL, AND OF THE PHILOSOPHICAL 

 SOCIETY OF YORK. 



WITH THE ASSISTANCE OF 



GENTLEMEN EMINENT IN SCIENCE AND LITERATURE. 



IN EIGHTEEN VOLUMES. 



VOLUME IV. 



EDINBURGH: 



PRINTED FOR WILLIAM BLACKWOOD ; 



AND JOHN WAUGH, EDINBURGH ; JOHN MURRAY ; BALDWIN & CRADOCK ; 

 J. M. RICHARDSON, LONDON; AND THE OTHER PROPRIETORS. 



M.DCCC.XXX. 





