ILLUSIONS AND HALLUCINATIONS. 633 



there seems to be an arrest of the processes of association. Such 

 are, for example, all hypnotic states. The analogy to the forms 

 of transmission of physical energy is striking, and has led Prof. 

 James to conjecture that the higher development of the few ideas 

 remaining is in some way a compensation for the arrest of asso- 

 ciation. " If ,^' he says, " we regard association paths as paths of 

 drainage, then the shutting off of one after another of them as the 

 cerebral paralysis advances ought to act like the plugging of a 

 hole in the bottom of a pail, and make the activitj'" more intense 

 in those systems of cells which retain any activity at all." Prof. 

 James then quotes from Taine a vivid description of the rise in 

 the level of the idea trains as the association paths are closed by 

 sleep. " All external sensations are gradually effaced, or cease at 

 any rate to be remarked ; the internal images, on the other hand, 

 feeble and rapid during the state of complete wakefulness, be- 

 come intense, distinct, colored, steady, and lasting : there is a sort 

 of ecstasy, accompanied by a sense of expansion and comfort. 

 Architecture, landscapes, moving figures, pass slowly by, and 

 sometimes remain with incomparable clearness of form and full- 

 ness of being ; sleep comes on, and I know no more of the real 

 world I am in. Many times, like M. Maury, I have caused myself 

 to be gently roused at different moments of this state, and have 

 thus been able to mark its characters. The intense image which 

 seems an external object is but a more forcible continuation of 

 the feeble image which an instant before I recognized as internal ; 

 some scrap of a forest, some house, some person which I vaguely 

 imagined on closing my eyes has in a minute become present to 

 me with full bodily details, so as to change into a complete hal- 

 lucination. Then, waking up on a hand touching me, I feel the 

 figure decay, lose color, and evaporate ; what had appeared a sub- 

 stance is reduced to a shadow. In such a case I have often seen, 

 for a passing moment, the image groiv pale, waste away, and evap- 

 orate; sometimes on opening the eyes a fragment of landscape 

 or the skirt of a dress appears still to float over the fire-irons 

 or the black hearth." 



In the three types which I have been discussing, the mental 

 state was present as a thought before being externalized as a hal- 

 lucination, and for many reasons hallucinations of this type are 

 the most instructive. But very often the hallucination is not only 

 not a mere externalization of a thought already present, but has 

 no apparent connection with anything of which the patient is at 

 the time thinking. Hence the theory of development needs to be 

 supplemented by other considerations, and one may draw them 

 from either of two quite different, although I think not inconsist- 

 ent, points of view. In the first place, one may suppose that the 

 hallucination is sometimes initiated from without, through some 



VOL. XLIX. — 50 



