AT THE CAPE OF GOOD HOPE. 
305 
stone was deposited by the sea rising to an incalculable height above 
the granite. The phenomena attending the junction of the sand- 
stone with the granite agrees with this view of the subject, and 
can be as satisfactorily explained on the Wernerian, as those at- 
tending the junction of the granite and schistus can on the Huttonian 
theory. The intermediate beds between the sandstone and granite 
are of a coarse earthy fracture. The superincumbent sandstone, on 
the contrary, becomes of a more crystalline structure in proportion 
as it recedes from them. These two facts are obviously con- 
formable to the laws before quoted respecting the causes which 
modify crystallization, or which are necessary to the formation of 
rocks, by a deposit more or less mechanical. For the motion of 
the sea, being greater near its surface than at a great depth, would 
be chiefly influential in preventing any tendency to crystallization 
when it first flowed over the granite ; but as it rose much above 
it, the subsequent deposits would be less agitated and acquire a 
more crystalline character. One more remark respecting the decom- 
posed state of the constituents of granite may be made in this place ; 
namely, that from whatever cause they acquired this state, they have 
not reassumed their crystalline forms, although subjected to enormous 
pressure for an incalculable period. 
The appearances, then, which I have described, and the conclu- 
sions that I have ventured to draw, seem to point out four different 
eras, corresponding to as many separate conditions of the rocks con- 
stituting the peninsula of the Cape. The first, indefinite as to its 
commencement, continued whilst the schistus reposed at the bottom 
of the sea, and terminated when the granite in fusion burst through 
it and formed dry land. The second commencing at this epoch, ter- 
minated when the water rose above the granite. The third had its 
duration whilst the water stood high above the earth and deposited 
the sandstone. The fourth commenced with the retrocession of the 
water and the appearance of the present dry land, and will terminate 
with the existing order of things. Another consequence of the fact 
that I have cited appears to be, that the mountains at the Cape of 
R R 
