2 ee 
222 Prof. Silliman’s Address before the 
zed communities the most ample means of wealth and of un- 
limited improvement. Geology, although not carried to perfec- 
tion, is truly a science ; for— 
‘Its ascertained facts are numerous; they are correctly observed 
and reported ; they are skillfully aitindh and arranged, and a suffi- 
cient number of general as well as particular conclusions, has 
been drawn from them, to furnish the basis of a most interesting 
science. Its boundaries are daily extending, and will be extend- 
ed without limit by continued observations; its evidence will 
therefore constantly accumulate, and although its theoretical 
speculations may change, nothing can occur to subvert the grand 
conclusion that the earth has a regular structure, and that its ma- 
terials have been arranged, under the operation of general laws 
of great energy and duration,’ the physical expression of omnis- 
cient intelligence and omnipotent sway, guided by benevolent 
design, which becomes more and more apparent and convincing 
with every new and successful research in geology.” 
OF ITS OBJECT, MEANS, AND ENDS. 
Geology discloses the structure of the earth, and the nature of 
the mineral masses of which it is composed—the order of theit 
succession and arrangement—the chemical composition of the 
rocks—the distinct minerals and the remains of organized beings 
which they contain—the veins and beds of metals—the strata of 
coal, limestone, plaster of Paris, mineral salt, clay, sand, and 
other materials useful or indispensable to civilized society ; and 
it investigates the proximate causes which have produced 
various effects that we behold, and which still continuing to 0P& 
rate will, in all future time, go on to produce their appropriate 
results. 
It might seem to a common observer, that, treading only upon 
the crust of the earth, we can know very little of the deep inte 
rior of a , whose diameter is eight thousand miles ; and that 
therefore attempt to ascertain its structure, must be equally 
iiiaieiions and vain. But the geologist finds much more 
ample sources of information than might at first ap 
~ “Every artificial excavation—every well and cellar—every eut 
fora fort; fora common road, a erent) ora eanal—every stone- 
ee ee 
* The Satay salad wb Maucl's Wena Wah. Am. edition. 
