irregularly shaped, unrolled flints, often with the colour and appearance
of huge bones, which were originally embedded in the chalk, contains not a
particle of carbonate of lime. This bed of red clay lies on a very
irregular surface, and often descends into deep round wells, the origin of
which has been explained by Lyell. In these cavities are patches of sand
like sea-sand, and like the sand which alternates with the great beds of
small pebbles derived from the wear-and-tear of chalk-flints, which form
Keston, Hayes and Addington Commons. Near Down a rounded chalk-flint is a
rarity, though some few do occur; and I have not yet seen a stone of
distant origin, which makes a difference--at least to geological eyes--in
the very aspect of the country, compared with all the northern counties.

The chalk-flints decay externally, which, according to Berzelius ("Edin.
New Phil. Journal," late number), is owing to the flints containing a small
proportion of alkali; but, besides this external decay, the whole body is
affected by exposure of a few years, so that they will not break with clean
faces for building.

This bed of red clay, which renders the country very slippery in the winter
months from October to April, does not cover the sides of the valleys;
these, when ploughed, show the white chalk, which tint shades away lower in
the valley, as insensibly as a colour laid on by a painter's brush.

Nearly all the land is ploughed, and is often left fallow, which gives the
country a naked red look, or not unfrequently white, from a covering of
chalk laid on by the farmers. Nobody seems at all aware on what principle
fresh chalk laid on land abounding with lime does it any good. This,
however, is said to have been the practice of the country ever since the
period of the Romans, and at present the many white pits on the hill sides,
which so frequently afford a picturesque contrast with the overhanging yew