I leaned forward
to examine it through the opening, a rush of mephitic air gave me a sort
of vertigo. "Come away, children," cried I, in terror; "the air you
would breathe there is certain death." I explained to them that, under
certain circumstances, carbonic acid gas was frequently accumulated in
caves or grottoes, rendering the air unfit for respiration; producing
giddiness of the head, fainting, and eventually death. I sent them to
collect some hay, which I lighted and threw into the cave; this was
immediately extinguished; we repeated the experiment several times with
the same result. I now saw that more active means must be resorted to.

We had brought from the vessel a box of fireworks, intended for signals;
I threw into the cave, by a cord, a quantity of rockets, grenades, &c.,
and scattered a train of gunpowder from them; to this I applied a long
match, and we retired to a little distance. This succeeded well; a great
explosion agitated the air, a torrent of the carbonic acid gas rushed
through the opening, and was replaced by the pure air; we sent in a few
more rockets, which flew round like fiery dragons, disclosing to us the
vast extent of the cave. A shower of stars, which concluded our
experiment, made us wish the duration had been longer. It seemed as if a
crowd of winged genii, carrying each a lamp, were floating about in that
enchanted cavern. When they vanished, I threw in some more lighted hay,
which blazed in such a lively manner, that I knew all danger was over
from the gas; but, for fear of deep pits, or pools of water, I would not
venture in without lights. I therefore despatched Jack, on his buffalo,
to report this discovery to his mother, and bring all the candles she
had made. I purposely sent Jack on the errand, for his lively and poetic
turn of mind would, I hoped, invest the grotto with such charms, that
his mother would even abandon her wheel to come and see it.

[Illustration: "This succeeded well; a great explosion agitated the
air--a torrent of the carbonic acid gas rushed through the opening."]

Delighted with his commission, Jack leaped upon his buffalo, and, waving
his whip, galloped off with an intrepidity that made my hair stand on
end. During his absence, Fritz and I enlarged the opening, to make it
easy of access, removed all the rubbish, and swept a road for mamma. We
had just finished, when we heard the sound of wheels crossing the
bridge, and the cart appeared, drawn by the co