rial so produced is still
known in trade as bay-salt. By-and-by, when people came to discover the
inland brine-pits and salt mines, they transferred to them the familiar
name, a wich; and the places where the salt was manufactured came to be
known as wych-houses. Droitwich, for example, was originally such a
wich, where the droits or dues on salt were paid at the time when
William the Conqueror's commissioners drew up their great survey for
Domesday Book. But the good, easy-going mediaeval people who gave these
quaint names to the inland wiches had probably no idea that they were
really and truly dried-up bays, and that the salt they mined from their
pits was genuine ancient bay-salt, the deposit of an old inland sea,
evaporated by slow degrees a countless number of ages since, exactly as
the Dead Sea and the Great Salt Lake are getting evaporated in our own
time.

Such, nevertheless, is actually the case. A good-sized Caspian used to
spread across the centre of England and north of Ireland in triassic
times, bounded here and there, as well as Dr. Hull can make out, by the
Welsh Mountains, the Cheviots, and the Donegal Hills, and with the Peak
of Derbyshire and the Isle of Man standing out as separate islands from
its blue expanse. (We will beg the question that the English seas were
then blue. They are certainly marked so in a very fine cerulean tint on
Dr. Hull's map of Triassic Britain.) Slowly, like most other inland
seas, this early British Caspian began to lose weight and to shrivel
away to ever smaller dimensions. In Devonshire, where it appears to have
first dried up, we get no salt, but only red marl, with here and there a
cubical cast, filling a hole once occupied by rock-salt, though the
percolation of the rain has long since melted out that very soluble
substance, and replaced it by a mere mould in the characteristic square
shape of salt crystals. But Worcestershire and Cheshire were the seat of
the inland sea when it had contracted to the dimensions of a mere salt
lake, and begun to throw down its dissolved saline materials. One of the
Cheshire beds is sometimes a hundred feet thick of almost pure and
crystalline rock-salt. The absence of fossils shows that animals must
have had as bad a time of it there as in the Dead Sea of our modern
Palestine. The Droitwich brine-pits have been known for many centuries,
since they were worked (and taxed) even before the Norman Conquest, as
were many other similar wells