TO 



WILLIAM MACLURE, 



PRESIDENT OF THE ACADEMY OF NATURAE SCIENCES OF 

 PHILADELPHIA- AND OF THE A3IERICAN GEOLO- 



GICAL society: 



ME3I11ER OF THE AMERICAN PHILOSOPHICAL SOCIETY, 



&C. &C. 



this book is dedicated as a small, but sincere tribute of 

 resj^ect and friendship, 



by his much obliged friend 



THE AUTHOR. 





