130 
Hints for a Theory of the Earth. 
7- Whether this sand contains, like that of Rimini, 
microscopic shells of the order of those called pelagian ? 
8. Whether there are not shells on the borders of the 
sea ; and, if there are, to determine those by which that 
coast seems to be characterised. 
9. Whether there are any rolled pebbles ? 
10. To examine, as in No. S, chiefly on the shore, and 
even pretty far up the country, whether there are any 
proofs that the sea gains on the land, or the latter on the 
sea ; and, in case the sea seems to recede, to discover 
whether that may not be occasioned by the land rising 
by accumulations washed down from the higher grounds ; 
by subterranean causes, or reciprocally. 
11. If a progressive displacing of the ocean really ex- 
ists, by what observations can the systems, which tend 
to explain it, be verified ? Some have employed, for that 
purpose, the currents produced by the trade winds ; 
others, the shock of the tides and currents ; and others, 
a change in the earth’s centre of gravity, occasioned ei- 
ther by deposits transported by rivers to the sea, or by 
the progressive movement of some mass detached from 
the interior parts of the earth supposed to be concave,-* 
(To he "continued. J 
* 12. To observe whether there are not daily formed different kinds of stones 
in the places which are washed by the waters of the sea. Til. 
