operation.

Of the manner of deposition he says: "The solution of iron in vegetable
acid (in which the iron is in what the chemist calls the form of a
protosalt) is oxidized by the action of the air on the surface of the
lake into a persalt, which is insoluble, and appears on the surface in
patches that display the peculiar iridescence characteristic of
petroleum floating on water. Indeed, not infrequently these films of
peroxide of iron are incorrectly attributed to petroleum. These films
become heavy by addition of new particles; they sink through the water,
and in this manner, in time, a large amount of iron ore is deposited on
the lake bottom. It must not be supposed that the ore is deposited as a
fine mud or sediment. On the contrary, in this lake ore, as it is
called, we have an excellent illustration of what is called
concretionary action--that is, the tendency of matter when in a fine
state of division to aggregate its particles into masses about some
central nucleus, which may be a fragment of sunken wood, a grain of
sand, or indeed a pre-formed small mass of itself."

It is claimed for this water ore, which is gathered like oysters, that
mixed with bog ore and magnetic iron, and smelted with charcoal, the
result as obtained is strong, durable and high priced.

The curiously elastic quarter of a mile finally yielded to persistent
toil, and the cave was reached. The entrance is sufficiently broad to
give a good first impression, and is under a heavy ledge of limestone
which breaks the slope of the hill and is artistically decorated with a
choice collection of foliage, among which is a coral honeysuckle; the
fragrant variety grows everywhere. Under the ledge is a narrow
vestibule, out of the north end of which is a passage about twenty-four