444 ON THE GEOLOGY OF THE 
careous cement, but fastened, as they are in the ocean, to the 
soil on which they grow. 
From these facts, it seems to be quite evident, that these 
shells must have been deposited at different periods, during 
the tardy formation of the gravel heaps in which they are im- 
bedded ; and also, that the heaps must have required a long 
time for their accumulation, not only from the growth of the 
beds of shells, but from the nature of the materials of which 
the hills are composed, and the distance from which these have 
been transported. When we consider the time required for 
the destruction of the original rocks, and for reducing them 
to their present state, it carries the mind back to a period, 
compared to which that of history is but a trifle. In the whole 
of these operations, we see no marks of hurry and confusion, 
no trace of those convulsions which must have preceded 
them, previous to the formation of the Mediterranean marble. 
On the contrary, from the disposition of the materials them- 
selves, and from the extreme delicacy, and state of perfection 
in which many of the shells have been found, there is next to 
a positive proof, that the accumulation must have proceeded 
with the utmost tranquillity, and that these heaps of gravel 
must have been carried gradually down, and quietly deposited 
in the sea. dw 
The shape which they present is also analogous to the na- 
ture of the beach in the vicinity of Nice, which, though compo- 
sed of loose pebbles, is remarkably shelving, and the sea be- 
comes suddenly very deep. Saussure states, that only a league 
from the shore, he found 1800 feet of water. Hence, supposing a 
turther depression of the Mediterranean, we should just have 
such another series of steep acclivities as the gravel banks now 
present, the sides and extent of which would in time be fur- 
rowed and indented by the running of torrents. 
There 
