(TO BE CONTINUED.) SOMNAMBULISM. That a person deeply immersed in thought, should, like Dominie Sampson, walk along in a state of "prodigious" unconsciousness, excites no surprise, from the frequency of the occurrence; but that any one should, when fast asleep, go through a series of complicated actions which seem to demand the assistance of the senses while closed against ordinary external impressions is, indeed, marvelous. Less to account for this mysterious state of being, than to arrange such a series of facts as may help further inquiry into the subject, we have assembled several curious circumstances regarding somnambulism. Not many years ago a case occurred at the Police-office at Southwark, of a woman who was charged with robbing a man while he was walking in his sleep during the daytime along High-street, in the Borough, when it was proved in evidence that he was in the habit of walking in his somnambulic fits through crowded thoroughfares. He was a plasterer by trade, and it was stated in court that it was not an uncommon thing for him to fall asleep while at work on the scaffold, yet he never met with any accident, and would answer questions put to him as if he were awake. In like manner, we are informed that Dr. Haycock, the Professor of Medicine at Oxford, would, in a fit of somnambulism, preach an eloquent discourse; and some of the sermons of a lady who was in the habit of preaching in her sleep have been deemed worthy of publication. We remember meeting with the case of an Italian servant, who was a somnambulist, and who enjoyed the character of being a better waiter when he was asleep than when he was awake. Every book on the subject repeats the anecdote which has been recorded of the blind poet, Dr. Blacklock, who, on one occasion, rose from his bed, to which he had retired at an early hour, came into the room where his family were assembled, conversed with them, afterward entertained them with a pleasant song, and then retired to his bed; and when he awoke, had not the least recollection of what he had done. Here, however, on the very threshold of the mystery, we meet with this difficulty--were these persons, when they performed the actions described, partially awake, or were they really in a state of profound sleep? In solving this problem, we shall proceed to consider some of the phenomena of somnambulism, premising only that if we avail ourselves of cases which the reader may before have met with, it is to throw light on what we may, perhaps, call the physiology of this very curious affection.