TO STRATIFIED ROCKS. 45 
In uiistratified crystalline rocks, wholly desti- 
tute of animal or vegetable remains, we search 
in vain for those most obvious evidences of con- 
trivance, which commence with the first traces 
of organic life, in strata of the transition period ; 
the chief agencies which these rocks indicate, 
are those of fire and water ; and yet even here we 
find proof of system and intention, in the pur- 
pose which they have accomplished, of supply- 
ing and accumulating at the bottom of the water 
the materials of stratified formations, which, in 
after times, were to be elevated into dry lands, 
in an ameliorated condition of fertility. Still 
more decisive are the evidences of design and 
method, which arise from the consideration of the 
conflicting theories that have been proposed to explain the most 
difficult and complicated problems of Geology, I select those 
which appear to carry with them the highest degree of probabi- 
lity; but as results remain the same from whatever cause they 
have originated, the force of inferences from these results will be 
unaffected by changes that may arise in our opinions as to the phy- 
sical causes by which these have been produced. As in estimat- 
ing the merits of the highest productions of human art it is not 
requisite to understand perfectly the nature of the machinery by 
which the work has been effected in order to appreciate the skill 
and talent of the artist by whom it was contrived ; so our minds 
may be fully impressed with a perception of the magnificent re- 
sults of creative intelligence, which are visible in the phenomena 
of nature, although we can but partially comprehend the mecha- 
nism that has been instrumental to their production ; and although 
the full developement of the workings of the material instruments 
by which they were effected, has not yet been, and perhaps may 
never be, vouchsafed to the prying curiosity of man. 
