OF SLEEP AND SOMNAMBULISM. 711 



the practice of gently rubbing some part of the body, which has been success- 

 fully employed by many who could not otherwise compose themselves to sleep. 

 The reading of a dull book acts in the same mode through the visual sense ; 

 for the eyes wander on from line to line, and from page to page, receiving a 

 series of sensorial impressions which are themselves of a very monotonous 

 kind, and which only tend to keep the attention alive in proportion as they 

 excite interesting ideas. 



575. In these and similar cases the influence of external impressions would 

 seem to be exerted in withdrawing the mind from the distinct consciousness 

 of its own operations (the loss of which is the transition-state towards that 

 of complete unconsciousness), and in suspending the directing power of the 

 Will. And this is the case, even where the attention is in the first instance 

 voluntarily directed to them ; as in some of the plans which have been 

 recommended for the induction of sleep, when there exists no spontaneous 

 disposition to it. In other methods, the attention is fixed upon some internal 

 train of thought, which, when once set going, may be carried on automat- 

 ically ; such as counting numbers, or repeating a French, Latin, or Greek 

 verb. In either case, when the sensorial consciousness has been once steadily 

 fixed, the monotony of the impression (whether received from the Organs of 

 Sense, or from the Cerebrum) tends to retain it there ; so that the Will 

 abandons, as it were, all control over the operations of the mind, and allows 

 it to yield itself up to the soporific influence. This last method is peculiarly 

 effectual when the restlessness is dependent up/m some mental agitation ; 

 provided that the Will has power to withdraw the thoughts from the excit- 

 ing subject, and to reduce them to the tranquillizing state of a mere mechan- 

 ical repetition. 



576. The access of Sleep is sometimes quite sudden ; the individual pass- 

 ing at once from a state of complete mental activity to one of entire torpor. 

 More generally, however, it is gradual ; and various intermediate phases 

 may be detected, some of which bear a close resemblance to the state of 

 Reverie. The same may be said with regard to the transition from the state 

 of Sleep to that of wakeful activity ; and this also may be sudden and com- 

 plete, although it usually consists of a succession of stages the complete 

 consciousness of the individual's relation to the external world, and the 

 power of directing his thoughts and actions to any subject about which he 

 may be required to exert himself, being the last to return to him. There 

 may be a rapid alternation of these different states; the loss and recovery 

 of the waking consciousness being many times repeated in the course of a 

 few minutes, when the circumstances are such as to prevent the access of 

 profound sleep by the recurrence of sensory impressions; as when a man on 

 horseback, wearied from want of rest, lapses at every moment into a dozing 

 state, from which the loss of the balance of his body as frequently and sud- 

 den arouses him ; or when a man going to sleep in a sitting posture, grad- 

 ually loses the support of the muscles which keep his head erect, his head 

 droops by degrees, and at last falls forward on his chest, and the slight shock 

 thence ensuing partially arouses and restores his voluntary power, which 

 again raises the head. Similar fluctuations occur in the sensory perceptions; 

 and these may be often artificially induced by very simple means. " We 

 find, for example, one condition of sleep so light, that a question asked re- 

 stores consciousness enough for momentary understanding and reply ; and 

 it is an old trick to bring sleepers into this state, by putting the hand into 

 cold water, or produce some other sensation, not so active as to awaken, but 

 sufficient to draw the mind from a more profound to a lighter slumber. 

 This may be often repeated, sleep still going on; but make the sound louder 

 and more sudden, and complete waking at once ensues. The same with 



