successive apparitions of his cat, his gentleman-usher, and the fatal
skeleton, may occupy, for a brief or almost momentary space, the vision
of men who are otherwise perfectly clear-sighted. Transitory deceptions
are thus presented to the organs which, when they occur to men of
strength of mind and of education, give way to scrutiny, and their
character being once investigated, the true takes the place of the
unreal representation. But in ignorant times those instances in which
any object is misrepresented, whether through the action of the senses,
or of the imagination, or the combined influence of both, for however
short a space of time, may be admitted as direct evidence of a
supernatural apparition; a proof the more difficult to be disputed if
the phantom has been personally witnessed by a man of sense and
estimation, who, perhaps satisfied in the general as to the actual
existence of apparitions, has not taken time or trouble to correct his
first impressions. This species of deception is so frequent that one of
the greatest poets of the present time answered a lady who asked him if
he believed in ghosts:--"No, madam; I have seen too many myself." I may
mention one or two instances of the kind, to which no doubt can be
attached.

The first shall be the apparition of Maupertuis to a brother professor
in the Royal Society of Berlin.

This extraordinary circumstance appeared in the Transactions of the
Society, but is thus stated by M. Thiebault in his "Recollections of
Frederick the Great and the Court of Berlin." It is necessary to premise
that M. Gleditsch, to whom the circumstance happened, was a botanist of
eminence, holding the professorship of natural philosophy at Berlin, and
respected as a man of an habitually serious, simple, and tranquil
character.