7 6z THE POPULAR SCIENCE MONTHLY. 



instance, the flavor was that of strong Roquefort cheese, and in another 

 of pears. 



The difference between illusions and hallucinations can be recoor- 

 nized without difficulty, for the latter are entirely cerebral in origin, 

 and do not require, as do the former, a material basis. They can not 

 be produced by any defects or derangements of the sensory organs, or 

 by any external circumstances tending to interfere with the normal ac- 

 tion of these organs. We have to consider them now as resulting from 

 disorder of the perceptional ganglia without the implication of those 

 parts of the brain which are concerned in the production of intellect, 

 emotion, or will. 



The case of Nicolai, the German bookseller, is a striking instance 

 of hallucinations of sight. For ten months he had been a good deal 

 disturbed by several melancholy incidents. A customary blood-letting 

 was omitted, and added to all was an unusual press of business mat- 

 ters. One morning he suddenly perceived, at apparently the distance 

 of ten steps, a form like that of a deceased person. The phantom 

 continued only for about ten minutes, but in the afternoon it reap- 

 peared. He arose and went to another room, the apparition accom- 

 panying him disappearing, however, at intervals, and always main- 

 taining the erect posture. Later there appeared other figures, unlike 

 the first. 



After the first day the figure of the deceased person no longer ap- 

 peared, but its place was supplied by many other phantoms, sometimes 

 representing acquaintances, but mostly strangers. After about four 

 weeks he began to hear them talk. The application of leeches to the 

 arms relieved him promptly of his hallucinations. 



Hallucinations of hearing are more common than those of any 

 other of the special senses, and, according to my experience, are more 

 apt to lead to further mental disorder. Far more people kill them- 

 selves under the influence of hallucinations of hearing than from 

 those of all the other senses combined. The reiteration in the ears, 

 during every minute of the day, of the command to jump into the 

 river, to plunge a convenient knife into the heart, and so on, day in 

 and day out, is calculated to shake the power of control of the strong- 

 est-minded. 



Sometimes a single word or a few words constitute the hallucina- 

 tion, but in their more complex character they are sentences and even 

 long discourses. No instance that has come under my observation 

 equals that of a lady who hears recited to her long pieces of original 

 poetry or prose. She has repeatedly written down these recitations 

 and brought them to me. This lady had a strong hereditary ten- 

 dency to insanity, and, shortly after the development of the hallu- 

 cinations referred to, she imbibed the delusion that she had com- 

 mitted the " unpardonable sin." She made two attempts at suicide, 

 and is still insane, but has an unusual circumstance lost the delu- 



