SOLIDIFICATION OF SAND. 167 
ried into them during the process of deposition. If 
we disturb any of these beds, we find shells, bones, 
or vegetables, which will differ according to the cir- 
cumstances under which the beds have been form- 
ed. In the deposites of fresh-water rivers, the re- 
mains of fresh-water animals will be found ; in those 
of the sea, marine animals will be abundant. 
Geologists have accordingly availed themselves 
of this important fact ; and when they find the re- 
mains of terrestrial and fresh-water animals in a 
deposite, they call it a fresh-water bed, and thus ob- 
tain some information concerning the circumstan- 
ces under which it was formed. 
Let us now suppose that these beds of clay and 
of sand at the bottom of seas and of rivers are rais- 
ed above the surface of the water, and exposed to 
heat and pressure, in what would they differ from 
any similar beds associated with known rocks'? 
Is it beyond the bounds of possibility that this 
may eventually occur, and what is now covered by 
water may become dry ground Geologists believe 
that this has happened in the instance of all those 
rocks whose stratified texture evinces that they 
were at a former period produced by deposition ; 
and it is not unphilosophical to believe, that what 
has happened once may happen again. Indeed, it 
is well ascertained that the new-formed strata of 
the seas of Asia Minor consist of stone^ and not of 
loose, incoherent materials. Almost all the streams 
and rivers, like many of those in Tuscany and the 
south of Italy, hold abundance of carbonate of lime 
in solution, which serves to bind together the sand 
and gravel into solid sandstones and conglomerates . 
