138 Hints for the Formation of 
3. The sensible flux and reflux out of the ocean, at 
the extremity of some gulfs and in some straits ; their 
periods and their limits. 
3. Their bottom ; notes of the places where they are 
deepest, and of the most remarkable shoals ; their posi- 
tion and extent. 
4. Currents at the surface or at different depths ; tlieir 
direction, velocity, and limits ; their relation to rivers, 
the winds, and form of the coasts ; the matters which 
they accumulate, and the places where they deposit 
them. 
5. Subterranean mountains and valleys ; their relation 
with islands, and even with the terrestrial mountains and 
valleys. 
6. The nature of the mud, sand, and rocks, of which 
the bed of every sea is composed. 
7- An analysis of the water of the different seas ; and, 
at least, their saltness at different depths and in different 
climates. 
8. Their temperature at different depths and in differ- 
ent climates. 
9. The iish and testaceous animals peculiar to differ- 
ent seas, depths, and climates, which may serve to cha- 
racterise them. 
10. In what the present seas differ, in a physical and 
chemical view, from the great ocean, which, according to 
some systems, is supposed to have covered the whole 
surface of our globe ? 
11. Can we believe that there are still formed stony 
strata at the bottom of the seas, and that their waters 
have consequently that dissolving power which is sup- 
posed to have belonged to the ancient ocean ? 
