124 PSYCHOLOGY. 



of snpplying it with water. One of these vessels stands 

 for the neighboring cortical cells, and can pour in hardly 

 any more water than goes out by the leak. The pail conse- 

 sequently never upsets in consequence of the supply from 

 this source. A current of water passes through it and does 

 work elsewhere, but in the pail itself nothing but what 

 stands for ideatiotial activity is aroused. The other vessel, 

 however, stands for the peripheral sense-organs, and cup- 

 plies a stream of water so copious that the pail ]3romptly 

 fills up in spite of the leak, and presently upsets ; in other 

 words, sensational activity is aroused. But it is obvious that 

 if the leak were plugged, the slower stream of supply 

 would also end by upsetting the pail. 



To apply this to the brain and to thought, if we take a 

 series of processes ABODE, associated together in that 

 order, and suppose that the current through them is very 

 fluent, there will be little intensity anywhere until, perhaps, 

 a pause occurs at E. But the moment the current is blocked 

 anywhere, say between C and D, the process in C must 

 grow more intense, and might even be conceived to explode 

 so as to produce a sensation in the mind instead of an idea. 



It would seem that some hallucinations are best to be 

 explained in this wa}-. We have in fact a regular series of 

 facts which can all be formulated under the single law thut the 

 substantive strength of a state of consciousness hears an inverse 

 proportion to its suggestiveness. It is the halting-places of 

 our thought which are occupied with distinct imagery. 

 Most of the words we utter have no time to awaken images 

 at all ; they simj)ly awaken the following words. But when 

 the sentence stops, an image dwells for awhile before the 

 mental eye (see Vol. I. p. 243). Again, whenever the asso- 

 ciative processes are reduced and impeded by the approach 

 of unconsciousness, as in falling asleep, or growing faint, or 

 becoming narcotized, we find a concomitant increase in the 

 intensity of whatever partial consciousness ma}^ survive. In 

 some people what M. Maury has called ' hypnagogic ' hal- 

 lucinations * are the regular concomitant of the process of 



* Le Sommeil et les Rfives (1865), chaps, m, iv. 



