with the reflection of the white hot lava beneath. These vapours
ascend to a great height, more than two thousand feet above the top
of the cone, which is itself twelve thousand feet above the level
of the sea.

There is found in these frozen regions a remarkable botanical
curiosity, having a certain connexion with volcanoes. The waters of
the ocean, all along the borders of the icy barrier, produce in
amazing abundance the family of water-plants named Diatomaceae. The
Diatoms are so called from their faculty of multiplying themselves
indefinitely by splitting into two; and so rapidly is this process
performed, that in a month a single diatom may produce a thousand
millions. The quantity found in the Antarctic regions is so immense
that, between the parallels of 60 degrees and 80 degrees of south
latitude, they stain the whole surface of the sea of a pale olive-
brown tint. These plants, which are so minute as to be individually
invisible, save under the higher powers of the microscope, have the
curious property of encrusting themselves with a sheath, or shell,
of pure silica. These shells remain after the death of the plant,
and are as indestructible as flint. They are marvellous objects,
both as respects the elegance of their forms and the beauty of
their markings. So great is the accumulation of these shells at the
bottom of the sea, that they have formed an immense bank 400 miles
in length by 120 in breadth, between the 76th and 78th degrees of
south latitude. One portion of this bank rests on the coast at the
foot of Mount Erebus.

Now, it is remarkable that these microscopic shells of Diatoms are
not unfrequently found in the ejections of volcanoes; while it is
generally supposed that, in the case of those situated near the