KEVERY, AND TRANCE. 



277 



those of loco-motion, walk in their sleep, without being conscious on their 

 Avaking of any such occurrence. 



Whatever be the set of fibres that have chiefly become exhausted from 

 the labour or stimulus of the day, the rest, as i have already noticea, par- 

 take of the torpitude from a habit of association ; exhausted in some ' 

 degree also themselves, by the share of sensorial power which, as from a 

 common stock, tuey have contributed towards the support of the debilitated 

 organ. But it sometimes happens, either from disease or peculiarity of 

 constitution, that all the organs of external sense do not associate in such 

 action, or yield alike to the general torpor of the frame : and that the au- 

 ditory, the optical, or some other sense, continues awake or in vigour 

 while all the other senses are beconie inert ; as it does also that such par- 

 ticular sense, Hke the muscles of particular members, as observed just above, 

 is awoke or re-stimulated into action in the midst of the soundest sleep, 

 by the peculiar force and bent of the dream, while all the rest continue 

 torpid. 



If the organ of external sense thus affected with wakefulness be that of 

 hearings a phaenomenon may occur which has often been noticed as far 

 back, indeed, as the times of the Greek and Roman poets, but which has \ 

 never hitherto, I believe, been satisfactorily explained ; the dreamer may 

 in this case hear a by-stander, who speaks to him ; and if, from a cause 

 above specified, he should also have happened to talk in his sleep, so as to 

 give the by-stander some clue into the train of thoughts of which his dream 

 j is composed, a conversation may be maintained, and the by-stander, by 

 I dexterous management, and the assumption of a character which he finds 

 I introduced into the dream, may be able to draw from the dreamer the 

 j profoundest secrets of his bosom ; the other senses of the dreamer, instead 

 I of hereby rousing to detect the imposition, being plunged into a still deeper 

 torpitude, from the demand of an increased quantity of sensorial power to 

 support the exhaustion which the wakeful or active organ is, in conse- 

 quence, sustaining. This, however, is a case of rare occurrence, though 

 ^it seems to have occurred occasionally. 



If the wakeful organ be that of sights and the dreamer, from a cause 

 just adverted to, be accustomed to walk instead of to talk in his sleep, he 

 will be able to make his way towards any place to which the course of his 

 j dream may direct him, with perfect ease, and without the smallest degree 

 \ of danger. He will see more or less distinctly, in proportion as the organ 

 I of sight is more or less awake ; yet from the increased exhaustion, and of 

 I course increased torpor of the other organs, in consequence of an increased 

 i demand of sensorial power from the common stock to support the action 

 I of the sense and muscles immediately engaged, every other sense must 

 1 necessarily be thrown into a deeper sleep or torpor than on any other oc- 

 casion. Hence the ears will not be roused even by a sound that might 

 otherwise awake him ; he will be insensible, not only to a simple touch, but 

 to a severe shaking of the hmbs : and may even cough violently without 

 being recalled from his dream. Having accomplished the object of his 

 I pursuit, he may safely return, even over the most dangerous precipices, 

 for he sees them distinctly, to his bed : and the organ of sight, being now 

 quite exhausted, or there being no longer any occasion for its use, may 

 once more associate in the general torpor, and the dream take a new turn, 

 and consists of a new combination of images. 

 The view we have thus taken of sleep and dreaming will explain a 



