The amount can be judged of by two methods,--by
the rate at which objects left on the surface are buried, and more
accurately by weighing the quantity brought up within a given time.
We will begin with the first method, as it was first followed.
Near Mael Hall in Staffordshire, quick-lime had been spread about
the year 1827 thickly over a field of good pasture-land, which had
not since been ploughed. Some square holes were dug in this field
in the beginning of October 1837; and the sections showed a layer
of turf, formed by the matted roots of the grasses, 0.5 inch in
thickness, beneath which, at a depth of 2.5 inches (or 3 inches
from the surface), a layer of the lime in powder or in small lumps
could be distinctly seen running all round the vertical sides of
the holes. The soil beneath the layer of lime was either gravelly
or of a coarse sandy nature, and differed considerably in
appearance from the overlying dark-coloured fine mould. Coal-
cinders had been spread over a part of this same field either in
the year 1833 or 1834; and when the above holes were dug, that is
after an interval of 3 or 4 years, the cinders formed a line of
black spots round the holes, at a depth of 1 inch beneath the
surface, parallel to and above the white layer of lime. Over
another part of this field cinders had been strewed, only about
half-a-year before, and these either still lay on the surface or
were entangled among the roots of the grasses; and I here saw the
commencement of the burying process, for worm-castings had been
heaped on several of the smaller fragments.
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