Many scores of men have, I fear, perished in the attempt to enter this
fearful place, carried on by their desire of gain. For it can scarcely
be disputed that untold treasures lie hidden therein, but guarded by
terrors greater than fiery serpents. These have usually made their
endeavours to enter in severe and continued frost, or in the height of a
drought. Frost diminishes the power of the vapour, and the marshes can
then, too, be partially traversed, for there is no channel for a boat.
But the moment anything be moved, whether it be a bush, or a willow,
even a flag, if the ice be broken, the pestilence rises yet stronger.
Besides which, there are portions which never freeze, and which may be
approached unawares, or a turn of the wind may drift the gas towards the
explorer.

In the midst of summer, after long heat, the vapour rises, and is in a
degree dissipated into the sky, and then by following devious ways an
entrance may be effected, but always at the cost of illness. If the
explorer be unable to quit the spot before night, whether in summer or
winter, his death is certain. In the earlier times some bold and
adventurous men did indeed succeed in getting a few jewels, but since
then the marsh has become more dangerous, and its pestilent character,
indeed, increases year by year, as the stagnant water penetrates deeper.
So that now for very many years no such attempts have been made.

The extent of these foul swamps is not known with certainty, but it is
generally believed that they are, at the widest, twenty miles across,
and that they reach in a winding line for nearly forty. But the outside
parts are much less fatal; it is only the interior which is avoided.

Towards the Lake the sand thrown up by the waves has long since formed a