eland, in certain great families, a Banshee, or a
_Benshee_, for they differ who spell it, sits and wails all night when
the head of the family is about to stretch his feet towards the dim
portals of the dead; and in England are many families who, by some
unknown means, retain a ghost which walks up and down a terrace, as it
did in that fanciful habitation of Sir Leicester Dedlock. In Scotland,
they have amongst them prophetic shepherds, who, on the cold, misty
mountain top, at eventide, shade their shaggy eyebrows with their hands,
and, peering into the twilight, see funerals pass by, and the decease of
some neighbor portended by all the paraphernalia of death.

With us all these portents "live no longer in the faith of Reason;" we
assert, in Casca's words, that "they are natural;" but we offend the
credulous when we do so. "Illusions of the senses," says an acute
writer, "are common in our appreciation of form, distance, color, and
motion; and also from a lack of comprehension of the physical powers of
Nature, in the production of images of distinct objects. A stick in the
water appears bent or broken; the square tower at the distance looks
round; distant objects appear to move when we are in motion; the
heavenly bodies appear to revolve round the earth." And yet we know that
all these appearances are mere illusions. At the top of a mountain in
Ireland, with our back to the sun, we, two travelers, were looking at
the smiling landscape gilded by the sunshine; suddenly a white cloud
descended between us and the valley, and there upon it were our two
shadows, distorted, gigantic, threatening or supplicatory, as we chose
to move and make them. Here was an exactly similar apparition to the
Specter of the Brocken. The untaught German taxed his wits to make the
thing a ghost; but the philosopher took off his hat and bowed to it, and
the shadow returned the salute; and so with the Fata Morgana, and the
mirage. We now know that these things had no supernatural origin, but
are simply due to the ordinary laws of atmospheric influence and light;
so all our modern illusions are easily rectified by the judgment, and
are fleeting and transitory in the minds of the sane.

But, beyond these, there are the illusions of which we first spoke, from
which we would not willingly be awakened. The sick man in Horace, who
fancied that he was always sitting at a play, and laughed and joked, or
was amazed and wept as they do in a theater, rightl