PREFACE. 



In the compilation of these pages no originality is claimed, but 

 the labours of modern authors have been freely appealed to, and 

 it is trusted, on every occasion, with due respect. A list of the 

 several authors consulted has been added at the end of the book. 



I have to acknowledge several obligations to my friend Dr. 

 Houston of this city, whose scientific acquirements and connec- 

 tion with the Museum of the College, have well qualified him for 

 the many auxiliary favours he has conferred on me. 



P. E. 



Dublin, 33 Aungier Street, 

 September, 1838. 



