No. lr,i.] 
115 
these tough and hard rocks'? Let the geologist go through this 
State in a north and south direction, on the line of the Hudson, 
and he will find them scattered from the northern highlands to the 
southern, and even to Long-Island. But limestone boulders could 
not withstand such violent diluvial action as must have existed to 
wash or carry along the granite rocks; they would be ground to 
powder against the hard masses which they would inevitably meet 
in those mighty currents. Now the disintegrating process which 
is continually going on with the limestone, has been going on from 
time immemorial; and not only so, but we have every reason to 
suppose that it was much more rapid in former times; and if so, 
then it must be, that the exposed surfaces were more extensive, 
and would of course furnish a greater quantity of calcareous mat- 
ter. All this would find its way to the ancient sea, and whether 
in solution or suspension merely, would furnish materials, not only 
for the coverings of animals, but also for the transition rocks. In 
this district, there is a silicious sedimentary rock underlying the 
transition limestone, usually known as sandstone, and this silicious 
matter is often mixed extensively with the limestone. The alter- 
nation of the gneiss and hornblende with the limestone, explains in 
part this peculiar character of these transition rocks, if we sup- 
pose their materials ever derived from the primitive formations of 
this region. We have, by this arrangement, silicious and calca- 
reous particles, abraded at the same time, and boih kinds would 
be carried to the ocean, but as silex is mostly insoluble, it would 
fall down in the form of a precipitate, while some considerable 
portion of the lime would be retained in solution. Whether the de- 
posite at the bottom of the ocean would be wholly silicious, or whol- 
ly calcareous, or a mixture of both, we can readily conceive would 
depend on circumstances, as whether the neighboring rocks which 
furnished materials were themselves silicious or calcareous, or of 
both kinds. 
We shall state here an inference which we have drawn from the 
repeated alternations of the primary rocks, as they occur not only 
in this district, but in all the primitive sections of our country. It is 
this, that we cannot establish any thing in relation to the age of the 
inferior stratified rocks. It was taught by Werner, and by his pu- 
pils after him, that granite, gneiss, mica slate, hornblende, granular 
limestone, &c. were deposited from an aqueous solution, in a cer- 
tain order—granite beneath, then gneiss, mica slate, &c. in the 
succession in which they are named ; and this succession was in 
