120 His emerald shallows, and his sapphire deeps.
Oft in wide lakes, around their warmer brim
In hollow pyramids the crystals swim;
Or, fused by earth-born fires, in cubic blocks
Shoot their white forms, and harden into rocks.


[_Hence with diffusive salt_. l. 119. Salts of various kinds are
produced from the recrements of animal and vegetable bodies, such as
phosphoric, ammoniacal, marine salt, and others; these are washed from
the earth by rains, and carried down our rivers into the sea; they seem
all here to decompose each other except the marine salt, which has
therefore from the beginning of the habitable world been perpetually
accumulating.

There is a town in the immense salt-mines of Cracow in Poland, with a
market-place, a river, a church, and a famous statue, (here supposed to
be of Lot's wife) by the moist or dry appearance of which the
subterranean inhabitants are said to know when the weather is fair above
ground. The galleries in these mines are so numerous and so intricate,
that workmen have frequently lost their way, their lights having been
burnt out, and have perished before they could be found. Essais, &c. par
M. Macquart. And though the arches of these different stories of
galleries are boldly executed, yet they are not dangerous; as they are
held together or supported by large masses of timber of a foot square;
and these vast timbers remain perfectly sound for many centuries, while
all other pillars whether of brick, cement, or salt soon dissolve or
moulder away. Ibid. Could the timbers over water-mill wheels or cellars,
be thus preserved by occasionally soaking them with brine? These immense
masses of rock-salt seem to have been produced by the evaporation of