and [Greek: morphe],
_morphe_, form.

ANTISEPTIC. Substances which prevent corruption in animal and
vegetable matter, as common salt does, are said to be antiseptic.
_Etym._, [Greek: anti], _anti_, against, and [Greek: sepo], _sepo_,
to putrefy.

ARENACEOUS. Sandy. _Etym._, _arena_, sand.

ARGILLACEOUS. Clayey, composed of clay. _Etym._, _argilla_, clay.

ARRAGONITE. A simple mineral, a variety of carbonate of lime, so
called from having been first found in Aragon in Spain.

ATOLLS. Coral islands of an annular form, or consisting of a
circular strip or ring of coral surrounding a central lagoon.

AUGITE. A simple mineral of a dark green, or black color, which
forms a constituent part of many varieties of volcanic rocks. Name
applied by Pliny to a particular mineral, from the Greek [Greek:
auge], _auge_, lustre.

AVALANCHES. Masses of snow which, being detached from great heights
in the Alps, acquire enormous bulk by fresh accumulations as they
descend; and when they fall into the valleys below often cause great
destruction. They are also called _lavanges_ and _lavanches_ in the
dialects of Switzerland.

BASALT. One of the most common varieties of the Trap-rocks. It is a
dark green or black stone, composed of augite and felspar, very
compact in texture, and of considerable hardness, often found in
regular pillars of three or more sides called basaltic columns.
Remarkable examples of this kind are seen at the Giant's Causeway,
in Ireland, and at Fingal's Cave, in Staffa, one of the Hebrides.
The term is used by Pliny, and is said to come from _basal_, an
AEthiopian word signifying iron. The rock often contains much iron.

"BASIN" of Paris, "BASIN" of London. Deposits lying in a hollow or
trough, formed of older rocks; sometimes used in geology almost
synonymously with "formations," to express the deposits lying in a
certain cavity or depression in older rocks.

BELEMNITE. An extinct genus of the order of molluscous animals
called Cephalopoda, having a long, straight, and chambered conical
shell. _Etym._, [Greek: belemnon], _belemnon_, a dart.

BITUMEN. Mineral pitch, of which the tar-like substance which is
often seen to ooze out of the Newcastle coal when on the fire, and
which makes it cake, is a good example. _Etym._, _bitumen_, pitch.

BITUMINOUS SHALE. An argillaceous shale