The partial character of the thinking and feeling processes in sleep, is well illustrated by the defect of thai form of judgment which constitutes taste. The most miserable doggerel may then pass before the mind as exquisite poetry. Orations may seem to be uttered worthy of the lips of Demosthenes, and arguments may be maintained which seem as irrefragable as the demonstrations of Euclid; and yet, were these reasonings and declamations uttered by a waking person, they would sound little better than the incoherent ravings of a maniac. Yet even to this general rule there have been remarkable exceptions. Gases are on record of judges who, in their sleep, have delivered decisions of the weightiest kind; and of poets who, in that state, have composed verses of great power and beauty, though they were by no means exempt from a certain degree of mystical indistinctness. The most striking instance is Mr. Coledbige's poem, entitled " Kubla Khan," which he himself characterised as a "psychological curiosity."

Another instance of the difference between dreaming and waking thought is that curious suspension of the moral sense, which is sometimes experienced. To this slumber of the conscience the virtuous are not less prone than the wicked. It is by no means true, as it has often been asserted, that the natural character is necessarily repeated in the state of dreaming. Frequently it is so; the brave enact prodigies of valour; the cowards die many deaths in their sleep; the compassionate are dissolved in grief for the woes of imaginary sufferers, and so on. But occasionally the reverse of this happens, just as in the analogous state of insanity. The pacific become pugnacious; the gentle and open-hearted entertain strange suspicions and animosities; and the pure give utterance to sentiments which shock us like the snatches of old songs that fall from the innocent lips of Ophelia. So in deep, deeds from which we should shrink with horror when awake, are performed, not only without the least remorse, but even without any question in our minds as to their propriety.

The seemingly extraordinary lapse of time has been often remarked in sleep, and it is easily explained. We can think of the events that compose the dream, in the same time as we dreamed them; but in the dream, these events, though only thought of, seem to be real, and seeming real, they leave the same impression of time on the mind as if they had actually happened. The feeling of time arises from the number of perceptions. The greater their number, and the more vivid and varied they are, the longer will seem to have been the time they occupied. It is just the reverse with thoughts. The more intense the latter, the less is the feeling of time. But in dreaming, what are really thoughts give the impression of outward perceptions, and, as such, excite a corresponding idea of time ; so that

"a thought, -A slumbering thought is capable of years, And curdles a long life into one hoar."

The sense of space is sometimes wonderfully affected. Mr. De Quinoy says, "buildings and landscapes were exhibited in proportions so vast, as the bodily eye is not fitted to receive. Space swelled and was amplified to an extent of unutterable infinity. This, however, did not disturb me so much as the vast expanse of time. I sometimes seemed to have lived 70 or 100 years in one night, - nay, sometimes had feelings representative of a millenium passed in that time, or a duration far beyond the limits of human experience."

On reviewing then the state of the mind in the sleeping man as compared with its condition in one awake, it does not appear that there is any one of the faculties, as some would say, or any one of the states of consciousness, as others would express it, which may not be exercised or exist in dreams. The sleeper may, though he does not ordinarily do so, see, hear, smell, taste and touch; he may, and commonly does, remember and imagine; he may reason, and reason rightly according to his premises; he may be agitated by the same passions, and be subject to the same refined sentiments of the moral, the sublime, and the beautiful, as when he is awake. Wherein, then, consists the difference ? Mainly in this, - that the mental processes are far less complete. Though specimens of any one of the classes of thoughts and feelings may be presented, the number and variety are very inferior to those of the waking state. Sensations occur so seldom as to be exceptional. The mind does not pass, so to speak, from perceptions to remembrances, and then back again to perceptions; and the associated ideas are so sparing, as to produce those defects of judgment which we have just noticed. The stores given up by memory, though often surprising in their variety and far-fetched character, are still very scanty, - as, for instance, when we remember and seem to behold the friend who died in our childhood, and yet forget that he is no more ; and the products of our imagination are not corrected by the judgment, because only a few associations arise in our minds. Though the moral sense is alert and even morbidly so at one time, at another it is quite paralysed. In short, I need not repeat, what I hope has been already sufficiently illustrated, that the great distinction between the two conditions, is one of degree rather than of kind. There is, however, one difference apparently of kind, namely, that which I have noticed as the actual or seeming intensity of revived sensations, and which, when occurring in our waking hours, produces the phenomena of spectral illusions. But even this difference is resolvable into one of degree. To sum up then: the materials of dreams are the same as those which belong to our waking life, though they are fewer in number, and occur in different degrees of intensity; and the laws which regulate their order and composition, are the same as those which operate in the other great division of our existence.

Having thus endeavoured to point out the leading features in which the phenomena of dreams resemble or differ from those of our waking thoughts and feelings, I proceed to inquire which of our past sensations are more likely to be renewed in the mental processes of sleep. And I may state in the onset, that much will depend in this respect on the character of sleep, as to its being healthy or unhealthy. In the former condition, I believe it will be found consistent with general observation, to say that the ideas (using this term as before to express the images of former perceptions), most apt to arise, are those which have been prompted by the events and the thoughts of the previous or recent days. I say prompted by the latter, for I do not consider it a character of healthy sleep to have the occurrences of the day renewed in it. The more strictly we analyse our dreams, the more perhaps we shall be struck by their connections with recent experience; and yet the entirely different and remote matter which constitutes the body of the dream is not less remarkable. By the operation of the laws of association, persons and things long by-gone and forgotten are recalled in such vivid colours, and they occupy so prominent a place in the vision, that the circumstances which suggested their recurrence are apt to be totally overlooked. This fact, though not much noticed by those who have investigated our subject, seems to me particularly interesting, because it affords a striking indication of the harmonious arrangement of the human economy. The mind is refreshed and invigorated by the presentation of images which have not recently occupied its attention, whether they occur in the form of simple revived perceptions, or are wrought up by imagination into combinations that have all the effect of novelty. And again, the faculties of passive memory and imagination which are thus employed, are precisely those which have been least exercised in the waking hours of the busy-minded man; while those which he most employs in the occupations of the day, namely, perception, active memory, and judgment, are enjoying complete repose. Whether listless day-dreamers are refreshed in the night season is a matter of little moment. I think it probable, that the machinery by which this beneficent contrivance is executed, is of the same nature as that which I endeavoured to point out on a former occasion, when treating of the efficient or physical cause of sleep. It is a general law, that the vital processes of nutrition and secretion are not equally active in all parts of the system at the same time, and that activity in one part is compensated by an opposite state in another part. When those portions of the brain which belong to the faculties of active observation and reflection have ceased to act, those in which memory and imagination reside, may be brought into play with but little demand on the strength of the system. This latter view is, however, hypothetical, and whether true or not, does not interfere with the importance or interesting nature of the fact which it seeks to explain.