The evaporation is extremely strong, and
favoured by the constant motion of the air; so that the salt is
collected in eighteen or twenty days after the pits are filled.
Though the muriate of soda is manufactured with less care in the
peninsula of Araya than at the salt-works of Europe, it is
nevertheless purer, and contains less of earthy muriates and
sulphates. We know not whether this purity may be attributed to
that portion of the salt which is furnished by the sea; for though
it is extremely probable, that the quantity of salt dissolved in
the waters of the ocean is nearly the same under every zone, it is
not less uncertain whether the proportion between the muriate of
soda, the muriate and sulphate of magnesia, and the sulphate and
carbonate of lime, be equally invariable.
Having examined the salt-works, and terminated our geodesical
operations, we departed at the decline of day to sleep at an Indian
hut, some miles distant, near the ruins of the castle of Araya.
Directing our course southward, we traversed first the plain
covered with muriatiferous clay, and stripped of vegetation; then
two chains of hills of sandstone, between which the lagoon is
situated.
