﻿0^ 



TO 



HENRY WALKER, Esq., 



OF LANARK, 

 AND 



FRANCIS WALKER, Esq., F.L.S., F.G.S., &c., 



OF SOUTHGATE, 



TO WHOM THIS WORK HAS BEEN GREATLY INDEBTED 



DURING ITS PROGRESS FOR THEIR NUMEROUS 



AND VALUABLE CONTRIBUTIONS, 



THE PRESENT VOLUME 



IS DEDIGATEr, 



IN TESTIMONY OF THE 



ESTEEM AND FRIENDSHIP OF 



THE AUTHOR. 



London, December 1, 1836. 



