causes which medical men find attended with the same symptom, of
embodying before the eyes of a patient imaginary illusions which are
visible to no one else. This persecution of spectral deceptions is also
found to exist when no excesses of the patient can be alleged as the
cause, owing, doubtless, to a deranged state of the blood or nervous
system.

The learned and acute Dr. Ferriar of Manchester was the first who
brought before the English public the leading case, as it may be called,
in this department, namely, that of Mons. Nicolai, the celebrated
bookseller of Berlin. This gentleman was not a man merely of books, but
of letters, and had the moral courage to lay before the Philosophical
Society of Berlin an account of his own sufferings, from having been, by
disease, subjected to a series of spectral illusions. The leading
circumstances of this case may be stated very shortly, as it has been
repeatedly before the public, and is insisted on by Dr. Ferriar, Dr.
Hibbert, and others who have assumed Demonology as a subject. Nicolai
traces his illness remotely to a series of disagreeable incidents which
had happened to him in the beginning of the year 1791. The depression of
spirits which was occasioned by these unpleasant occurrences, was aided
by the consequences of neglecting a course of periodical bleeding which
he had been accustomed to observe. This state of health brought on the
disposition to see _phantasmata_, who visited, or it may be more
properly said frequented, the apartments of the learned bookseller,
presenting crowds of persons who moved and acted before him, nay, even
spoke to and addressed him. These phantoms afforded nothing unpleasant
to the imagination of the visionary either in sight or expression, and
the patient was possessed of too much firmness to be otherwise affected
by their presence than with a species of curiosity, as he remained
convinced from the beginning to the end of the disorder, that these