582 Indications of Fertility or Barrenness of Soils. 
dissolution of any soil or rock, and the subsequent re-union, after 
a journey for miles through a country covered with vegetables, it 
would be impossible to avoid a mixture of this kind. The trans- 
ported soil which forms Chippenham Meadow would be deposited 
there when the country was very thinly peopled, or we might 
easily suppose it to contain the essence of millions of dunghills 
floated down the stream. No doubt it contains the essence of 
many, which, together with vegetable matter and the dead car- 
casses of animals, mingled in a journey of some 150 miles by the 
Wye alone, may be sufficient to account for the fertility of the 
soil on the banks and at the junction of these picturesque rivers. 
Some of the alluvial deposits in the rivers which run eastward 
are more recent accumulations, and some are now in a state of 
gradual formation. The richness of the soil of the more recently 
formed does not appear difficult to be accounted for. Ever since 
this island has been inhabited, the night-soil of all the villages 
and towns has been discharged into streams and rivulets, and all 
the urine, and a great deal of the best of the dung, from almost 
countless numbers of farm-yards in Great Britain, at present 
escape, and have done so for ages, into gutters, ditches, and 
streams of water, and those empty their contents into brooks and 
rivulets, and those into rivers, and the rivers again into estuaries. 
Here the great mass of floating manure is interrupted in its 
course by the rising tide and conveyed to the shores, and there 
deposited in the shape of mud. We need not wonder at alluvial 
deposits formed in this manner being universally fertile. 
One large deposit of this kind is situated in the river H umber, 
about 20 miles eastward of Hull, and is known by the name of 
Sunk Island. This tract of land has been taken from the large 
estuary at the mouth of the Humber, apparently at three different 
periods. A considerable time must have elapsed since the first 
reclaimed portion Mas taken possession of by man. It has 
timber-trees growing upon it which appear to be nearly or quite 
a hundred years old, and at one time it formed a complete island, 
with the mainland at a distance of a \ h mile or 2 miles to the 
northward. 
About 40 years ago an embankment was made, running north- 
ward, from the eastern end of the island to the land, and another, 
extending westward, to meet the northern bank of the H umber, 
where there is a small harbour called Stone Creek, at the point 
where the drainage-water of the lands on a higher level is, by 
means of flood-gates, allowed to empty itself into the river. This 
large tract between the island and the northern shore of the 
estuary thus became reclaimed, and was laid out into several 
farms, possessing a soil of a most fertile description, much of the 
land scarcely exhibiting, after 20 years' tillage, any symptom of 
