408 MAUEY ON SLEEP AND DKEAMS. 



All such aberrations are repeated and exaggerated in 

 dreams. The brain, physically affected in sleep, loses 

 more or less those perceptions of time, place, and per- 

 sonality which are wont to guide the succession of 

 mental acts. In the varying degrees of this influence 

 we may best find explanation of many of the anomalies 

 of somnambulism, trance, hypnotism, hysteria, &c., of 

 which we have already spoken. Here, however, as in 

 many questions of like kind, the explanation merely 

 removes one difficulty to bring us in contact with 

 others yet more insuperable. 



It has been a question how far the course and 

 objects of dreams can be changed by external stimuli 

 applied to the several senses of the dreamer. Such 

 excitements, it is well known, may be applied as to 

 modify variously the conditions of sleep without ac- 

 tually suspending it. The cradle of the sleeping child 

 affords sufficient evidence of the fact. Shakspeare had 

 this matter in his ever-pregnant mind when he brings 

 in Queen Mab as a fairy experimentalist upon dreams. 

 But graver experiments have been made on the sub- 

 ject some of them due to M. Maury himself. Though 

 we cannot doubt the reality of such influence in dif- 

 ferent modes and degrees, seeing what we gather both 

 from analogy and observation, yet are the particular 

 proofs of difficult attainment, and experiments need to 

 be often repeated and varied to give them their ap- 

 propriate value. We have more certainty as to the 

 influence of the internal organs on the course and 

 character of dreams. The digestive organs more espe- 

 cially disordered, it may be, by the dinner of the pre- 



