PREFACE. 
vil 
tematic treatise. In this part of the volume a 
method of classifying the subjects of geological re- 
search has been adopted, in accordance with the 
elementary views given in the first part, so as to 
present a large mass of arranged information in a 
small compass. The advantages attending this 
systematic plan are too obvious to need remark. 
The reader will perceive that I have extensively 
consulted the able works of Bakewell, Philips, Ly- 
ell, De la Beche, Ure, Conybeare, Buckland, Man- 
tell, Cuvier, &c., of Europe ; and the State Geolo- 
gical Reports of Messrs. Hitchcock, Jackson, Beck, 
Conrad, Featherstonhaugh, Emmons, Hall, Vanux- 
em. Eights, Eaton, Wm. B. and H. D. Rogers, Du- 
catel, Hildreth, Briggs, Troost, Mather, Percival, 
Shepherd, and Houghton ; whose labours are shed- 
ding a flood of light upon the geological structure 
and mineral treasures of this country. Besides 
these, I have had free access to all the scientific pe- 
riodical journals, and been favoured by Professors 
Torrey and Francis of this city with numerous im- 
portant documents, for which I desire to express my 
grateful acknowledgments. I have also drawn 
largely upon Mr. Maclure and Professor Silliman, 
whose names, indeed, ought to stand first on the list 
of American geologists ; for the able " Sketch of the 
Geology of the United States" by the former, and the 
"Journal of Science and the Arts" conducted by the 
latter, have done, perhaps more to difiuse a taste for 
geological studies among us than all other causes 
united. It will be seen that, in some instances, I 
have not hesitated to employ the language of others 
in the description of facts, where it seemed appro- 
priate ; but in the expression of opinions I have 
