Their airy tongues would syllable men's names
On sands, and shores, and desert wildernesses.

They were supposed to guide the wandering lights, that in the
obscurity of the night beguiled the weary traveller "through bog,
through bush, through brake, through briar." But their power of evil
only extended, or was only employed, to vex those who by a certain
obliquity of conduct gave occasion for their reproofs. They besides
pinched and otherwise tormented the objects of their displeasure; and,
though the mischiefs they executed were not of the most vital kind,
yet, coming from a supernatural enemy, and being inflicted by
invisible hands, they could not fail greatly to disturb and disorder
those who suffered from them.

There is at first sight a great inconsistency in the representations
of these imaginary people. For the most part they are described to us
as of a stature and appearance, almost too slight to be marked by our
grosser human organs. At other times however, and especially in the
extremely popular tales digested by M. Perrault, they shew themselves
in indiscriminate assemblies, brought together for some solemn
festivity or otherwise, and join the human frequenters of the scene,
without occasioning enquiry or surprise. They are particularly
concerned in the business of summarily and without appeal bestowing
miraculous gifts, sometimes as a mark of special friendship and
favour, and sometimes with a malicious and hostile intention.--But we
are to consider that spirits

Can every form assume; so soft
And uncompounded is their essence pure;