purgatory. The reason is not far to seek: ecclesiastical
chroniclers, like classical men of letters, recorded events which
interested themselves; a wraith, or common ghost ('matter of daily
experience,' says Lavaterus, and, later, contradicts himself), or
knocking sprite, was beneath their notice. In mediaeval sermons we
meet a few edifying wraiths and ghosts, returning in obedience to a
compact made while in the body. Here and there a chronicle, as of
Rudolf of Fulda (858), vouches for communication with a rapping
bogle. Grimm has collected several cases under the head of 'House-
sprites,' including this ancient one at Capmunti, near Bingen. {30}
Gervase of Tilbury, Marie de France, John Major, Froissart, mention
an occasional follet, brownie, or knocking sprite. The prayers of
the Church contain a petition against the spiritus percutiens, or
spirit who produces 'percussive noises'. The Norsemen of the Viking
age were given to second sight, and Glam 'riding the roofs,' made
disturbances worthy of a spectre peculiarly able-bodied. But, not
counting the evidence of the Icelandic sagas, mediaeval literature,
like classical literature, needs to be carefully sifted before it
yields a few grains of such facts as sane and educated witnesses
even now aver to be matter of their personal experience. No doubt
the beliefs were prevalent, the Latin prayer proves that, but
examples were seldom recorded.

Thus the dark ages do _not_, as might have been expected, provide us
with most of this material. The last forty enlightened years give
us more bogles than all the ages between St. Augustine and the
Restoration. When the dark ages were over, when learning revived,
the learned turned their minds to 'Psychical Research,' and Wier,
Bodin, Le Loyer, Georgius Pictorius, Petrus Thyraeus, James VI.,
collected many instances of the phenomena still said to survive.