PHYSICAL CHARACTERS. 
165 
observations, the relative difference, which was indeed 
variable, being of course modified by change of weather 
and other circumstances. 
The opposite sides of the river appear, according to 
Mr. Roscher, to be of different formation. Cape Nun, 
the termination of the right bank, has a long spit of 
sand running into the sea about one mile and a half. 
“ This shore is generally swampy, formed by a deposit of 
mud, brought down by the river, the outside of which 
presents a sandy appearance ; and is intersected by 
innumerable channels of water, of a brackish and putrid 
taste. Where dry spots are found, they are cultivated 
by the natives from the other side. The sand con- 
tinues till the sea meets the fresh-water stream. A 
deposit of lamellar mica, and fine vegetable matter, 
the last of which is brought down by the river, and 
washed out by the sea ; but the quantity is so small, 
that it would take centuries to form a stratum of any 
importance. The bed of the river is covered with a 
blue clay, rich in vegetable matter, and coloured by 
oxide of iron, similar to the clay observed in the bed of 
the sea outside the bar. Whenever the clay was broken 
by the rapidity of the current, the pieces were imme- 
diately carried off by the moving water ; and it often 
happened that the spring tides washed them ashore, in 
the shape of cylinders. These being left behind by the 
retreating ocean, formed one of the peculiar characters 
of the right bank of the river. 
The clay of the river-deposit is of a ferruginous 
