Moreover, it was not only just as salt as at the
present day, but even a great deal salter. For from that time to this
evaporation has constantly been going on in certain shallow isolated
areas, laying down great beds of gypsum and then of salt, which still
remain in the solid condition, while the water has, of course, been
correspondingly purified. The same thing has likewise happened in a
slightly different way with the lime and flint, which have been
separated from the water chiefly by living animals, and afterwards
deposited on the bottom of the ocean in immense layers as limestone,
chalk, sandstone, and clay.
Thus it turns out that in the end all our sources of salt-supply are
alike ultimately derived from the briny ocean. Whether we dig it out as
solid rock-salt from the open quarries of the Punjaub, or pump it up
from brine-wells sunk into the triassic rocks of Cheshire, or evaporate
it direct in the salt-pans of England and the shallow _salines_ of the
Mediterranean shore, it is still at bottom essentially sea-salt.
However distant the connection may seem, our salt is always in the last
resort obtained from the material held in solution in some ancient or
modern sea. Even the saline springs of Canada and the Northern States of
America, where the wapiti love to congregate, and the noble hunter lurks
in the thicket to murder them unperceived, derive their saltness, as an
able Canadian geologist has shown, from the thinly scattered salts still
retained among the sediments of that very archaic sea whose precipitates
form the earliest known life-bearing rocks.
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