Chapter XV.
Of Illusions.
Bt this term I mean that disease, in which &Ise perceptions take place in the ears and eyes in the waking state, from a morbid affection of the brain or of the sense which is the seat of the illusion. It may be considered as a waking dream. Persons affected with it, fancy they hear voices, or see objects that do not exist These false perceptions are said, by superstitious peo- ple, to be premonitions of death. They sometimes indicate either the forming state or the actual exbtence of disease, which being seated most commonly in a highly vital part of the body, that is, the brain, now and then ends in death, and thus administers support to superstition. They depend, Uke false perception in madness, upon motion being excited in a part of the ear or the eye, which does not vibrate with the impression
