y find their way by
groping. During the eruption of Vesuvius, in 1794, at Caserta, four
leagues distant, people could only walk by the light of torches. On the
first of May, 1812, a cloud of volcanic ashes and sand, coming from a
volcano in the island of St. Vincent, covered the whole of Barbadoes,
spreading over it so intense a darkness that, at mid-day, in the open
air, one could not perceive the trees or other objects near him, or
even a white handkerchief placed at the distance of six inches from the
eye._"--Murray, p. 215, Phil. edit._

(*6) In the year 1790, in the Caraccas during an earthquake a portion of
the granite soil sank and left a lake eight hundred yards in diameter,
and from eighty to a hundred feet deep. It was a part of the forest of
Aripao which sank, and the trees remained green for several months under
the water."--_Murray_, p. 221

(*7) The hardest steel ever manufactured may, under the action of a
blowpipe, be reduced to an impalpable powder, which will float readily
in the atmospheric air.

(*8) The region of the Niger. See Simmona's _Colonial Magazine_.

(*9) The Myrmeleon-lion-ant. The term "monster" is equally applicable
to small abnormal things and to great, while such epithets as "vast" are
merely comparative. The cavern of the myrmeleon is vast in comparison
with the hole of the common red ant. A grain of silex is also a "rock."

(*10) The _Epidendron, Flos Aeris,_ of the family of the _Orchideae_,
grows with merely the surface of its roots attached to a tree or other
object, from which it derives no nutriment--subsisting altogether upon
air.

(*11) The _Parasites,_ such as the wonderful _Rafflesia Arnaldii_.

(*12) _Schouw_ advocates a class of plants that grow upon living
animals--the _Plantae_ _Epizoae_. Of this class are the _Fuci_ and
_Algae_.

_Mr. J. B. Williams, of Salem, Mass._, presented the "National
Institute" with an insect from New Zealand, with the following
description: "'_The Hotte_, a decided caterpillar, or worm, is found
gnawing at the root of the _Rota_ tree, with a plant growing out of its
head. This most peculiar and extraordinary insect travels up both the
_Rota_ and _Ferriri_ trees, and entering into the top, eats its way,
perforating the trunk of the trees until it reaches the root, and dies,
or remains dormant, and the plant propagates out of its head; the body
remains perfect and entire, of a harder substance than when alive. From
this insect the nativ