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be improved by the application of sand, or clay. 
Soils too abundant in sand are benefited by the use 
of clay or marl, or vegetable matter. A field be- 
longing to Sir Robert Vaughan at Nannau, Me- 
rionethshire, the soil of which was a light sand, was 
much burnt up in the summer of 1805 ; I recom- 
mended to that gentleman the application of peat 
as a top-dressing. The experiment was attended 
with immediate good effects ; and Sir Robert has 
informed me, that the benefit was permanent. A 
deficiency of vegetable or animal matter must be 
supplied by manure. An excess of vegetable mat- 
ter is to be removed by burning, or to be remedied 
by the application of earthy materials. The im- 
provement of peats, or bogs, or marsh lands, must 
be preceded by draining ; stagnant water being 
injurious to all the nutritive classes of plants. Soft 
black peats, when drained, are often made pro- 
ductive by the mere application of sand or clay as 
a top-dressing. When peats are acid, or contain 
ferruginous salts, calcareous matter is absolutely 
necessary in bringing them into cultivation. When 
they abound in the branches and roots of trees, or 
when their surface entirely consists of living vege- 
tables, the wood or the vegetables must either be 
carried off, or be destroyed by burning. In the 
last case their ashes afford earthy ingredients, fitted 
to improve the texture of the peat. 
The best natural soils are those of which the 
materials have been derived from different strata ; 
which have been minutely divided by air and water, 
and are intimately blended together : and in im- 
