hallucination

[Lat. hallucinatio, allucinatio, from hallucinor, allucinor to wander in mind.] I. Ordinary Language : 1. A wandering in the mind; a mistake; a blun der. "This must have been the hallucination of the trans criber."-Add is on. *2. A defective or impaired state of the vision. II. Physiol.: Delusion (q. v.); belief in the exist ence of things which have no real existence. Deaf people hear sounds and blind see visions. No person can convince an insane person that the sounds he believes he hears, or that the forms he believes he sees, are other than real and substantial the hallucination being the false conception which he is unable to distinguish from a true perception. [ILLUSION.] Vertigo, or dizzine , presents a vivid hallucination of movement either of the body of the person suffering from it or of things surrounding him which are are really at rest. Double vision, in a certain stage of drunkenne , partakes of this nature, though it is rather an illusion than a hallucination.