PREFACE. 
XV 
confess, that wherever we have met with 
materials to our mind we have freely made 
use of them. This, however, has not been 
done without acknowledgment, as the 
names of the different authors, from whom 
we have derived information, are for the 
most part mentioned throughout the work. 
It will be but just in this place to confess 
our obligations to the engaging Spectacle de 
la Native, since we have taken from that 
book whatever has suited our purpose. 
From the excellent mineralogical works of 
Patrin * and Brongniart -f* we have also re- 
ceived great assistance, which we the more 
readily mention here, as we have not al- 
ways noticed their names when we have 
quoted their books. “ I am very sensible,” 
says Rollin, “ that it is not so much for a 
person’s reputation to make use of other 
men’s labours, and that it is in a manner 
renouncing the name and quality of author. 
* Histoire Naturelle des Miner aux, Paris 1803. 
t Traite Elementaire de Mineralogie , Paris 1807. 
