The Natural History of Selborne, Vol. 1 | Page 4

heavy blow of the beetle or mall or
mallet, the tree nodded to its fall; but still the dam sat on. At last, when
it gave way, the bird was flung from her nest, and, though her parental
affection deserved a better fate, was whipped down by the twigs which
brought her dead to the ground.

LETTER III.
The fossil-shells of this district, and sorts of stone, such as have fallen
within my observation, must not be passed over in silence. And first I
must mention, as a great curiosity, a specimen that was ploughed up in
the chalky fields, near the side of the Down, and given to me for the
singularity of its appearance, which, to an incurious eye, seems like a
petrified fish of about four inches long, the cardo passing for a head
and mouth. It is in reality a bivalve of the Linnaean Genus of Mytilus,
and the species of Crista Galli; called by Lister, Rastellum; by
Rumphius, Ostreum plicatum minus; by D'Argenville, Auris Porci, s.
Crista Galli; and by those who make collections, Cock's Comb.
Though I applied to several such in London, I never could meet with an
entire specimen; nor could I ever find in books any engraving from a
perfect one. In the superb museum at Leicester House, permission was
given me to examine for this article; and, though I was disappointed as
to the fossil, I was highly gratified with the sight of several of the shells
themselves in high preservation. This bivalve is only known to inhabit
the Indian Ocean, where it fixes itself to a zoophyte, known by the
name Gorgonia. The curious foldings of the suture the one into the
other, the alternate flutings or grooves, and the curved form of my
specimen, are much easier expressed by the pencil than by words.

Cornua Ammonis are very common about this village. As we were
cutting an inclining path up the Hanger, the labourers found them
frequently on that steep, just under the soil, in the chalk, and of a
considerable size. In the lane above Wall-head, in the way to Emshot,
they abound in the bank in a darkish sort of marl, and are usually very
small and soft; but in Clay's Pond, a little farther on, at the end of the
pit, where the soil is dug out for manure, I have occasionally observed
them of large dimensions, perhaps fourteen or sixteen inches in
diameter. But as these did not consist of firm stone, but were formed of
a kind of terra lapidosa, or hardened clay, as soon as they were exposed
to the rains and frost they mouldered away. These seemed as if they
were a very recent production. In the chalk-pit, at the north-west end of
the Hanger, large nautili are sometimes observed.
In the very thickest strata of our freestone, and at considerable depths,
well-diggers often find large scallops or pectines, having both shells
deeply striated, and ridged and furrowed alternately. They are highly
impregnated with, if not wholly composed of, the stone of the quarry.

LETTER IV.
As in a former letter the freestone of this place has been only
mentioned incidentally, I shall here become more particular.
This stone is in great request for hearth-stones, and the beds of ovens;
and in lining of lime-kilns it turns to good account, for the workmen
use sandy loam instead of mortar, the sand of which fluxes, and runs by
the intense heat, and so cases over the whole face of the kiln with a
strong vitrified coat-like glass, that it is well preserved from injuries of
weather, and endures thirty or forty years. When chiseled smooth, it
makes elegant fronts for houses, equal in colour and grain to Bath stone;
and superior in one respect, that, when seasoned, it does not scale.
Decent chimney-pieces are worked from it of much closer and finer
grain than Portland, and rooms are floored with it, but it proves rather
too soft for this purpose. It is a freestone cutting in all directions, yet
has something of a grain parallel with the horizon, and therefore should

not be surbedded, but laid in the same position that it grows in the
quarry. On the ground abroad this firestone will not succeed for
pavements, because, probably some degrees of saltness prevailing
within it, the rain tears the slabs to pieces. Though this stone is too hard
to be acted on by vinegar, yet both the white part, and even the blue rag,
ferments strongly in mineral acids. Though the white stone will not
bear wet, yet in every quarry at intervals there are thin strata of blue rag,
which resist rain and frost, and are excellent for pitching of stables,
paths, and courts, and for building of dry walls