In this case the dream may have depended in part upon internal sensations, but the intense excitement probably produced phantasms which impressed it so vividly upon the memory; for although he had not yet reached the water, his imagination was bathing his thirsty soul in "many a crystal fountain."

"The minds of sleeping persons," the Elder Gyrus says, "strongly manifest their divine origin; for when they are free and released from corporeal influences, they foresee much that is to be." We would say, that freedom from external relation often confers a scope of action, ordinarily irregular and indefinite, which surpasses in imagery, variety, rapidity, and comprehension, any train of thought the same individual can originate in a state of wakefulness. The Velocity with which the mind traverses space and time is almost inconceivable - in truth we are unable to grasp the rapidity with which it operates ; for when we reflect Upon the subjects presented in our most vivid dreams - circumstances essential, collateral, and accidental, are multiplied ad infinitum, until we are lost in the exuberance of thought which composed the vision.

The dreams of De Quincy, the "English Opium Eater," show this Wonderful power of the mental faculties when divested of the restraining influence of out-ward impressions. Probably every person has at some period of his life experienced this expansion of mind which he well remembers; although he retains only an undefined remembrance of the ideas. But when he reflects upon the subject, he is astonished with the vastness of the thoughts that floated through his mind, and he is constrained with the poet to exclaim uYea, in the strangeness of my vision, I Seemed to soar on wings."

The mental faculties may be as severely exercised when we are asleep as when awake. The intensity of action in either case depends upon the exciting cause. If the cause during sleep originate in the brain, or if it proceed from external influences, the mental operations thence take their course, sometimes consistent, as when the senses are partially intact, or inconsistent when they are in abeyance.

Phrenologists say, that the propensities and sentiments are excited by perceptions of the knowing and reflective faculties. This has reference to the waking state. But in sleep, the order is reversed. The intellectual powers receive their stimulus principally from internal sensations produced in the organs of feeling.

Dreams may be considered as. simple and complex. They are simple when the mind only is in action, and complex when the physical obeys the dictates of the mental being.

When the first shades of sleep descend upon us in consonance with our wishes, and the perception of external circumstances is vague and undefined, the mind is free to revel in all the delights of fancied happiness, or despond under the weight of imaginary affliction. This condition depends measurably upon our reflections previous to our falling into sleep; and although the mind takes on a pleasurable or painful train of thought in the commencement, it is not even probable that it will continue in it for any length of time, because one idea will lead to another, from some cause associated with circumstances which may be of an entirely different character from the one by which it was induced, and which, as the controlling influences of perfect sensational impressions are obstructed, will lead from pleasure to pain - from a sentiment of love to a feeling of revenge. In this way, the mind may be carried through all the various combinations of its ultimate elements. This mental process constitutes simple dreaming.

To illustrate the associate action of the mind in. sleep, we will transcribe the dream of Professor Maas. of Halle, and his analysis of its phenomena. The professor says that " I dreamed once that the Pope visited me. He commanded me to open my desk, and carefully examined all the papers it contained. While he was thus employed, a very sparkling diamond fell out of his triple crown into my desk, of which, however, neither of us took any notice. As soon as the Pope had withdrawn, I retired to bed; but was soon obliged to rise, on account of a thick smoke, the cause of which I had yet to learn. Upon examination I discovered that the diamond had set fire to the papers in my desk, and burned them to ashes."

In explanation he observes, that "On the preceding evening I was visited by a friend, with whom I had a lively conversation upon Joseph the Second's suppressions of monasteries and convents. With this idea, though I did not become conscious of it in the dream, was associated the visit which the Pope publicly paid to the Emperor Joseph, at Vienna, in consequence of the measure taken against the clergy; and with this again was combined, however faintly, the representation of the visit which had been paid me by my friend. These two events were, by the sub-reasoning faculty, compounded into one, according to the established rule, that things which agree in their parts also correspond as to the whole: hence the Pope's visit was changed into a visit made to me. The sub-reasoning faculty then, in order to account for this extraordinary visit, fixed upon that which was the most important object in my room, namely, the desk, or rather the papers it contained. That a diamond fell out of the triple crown was a collateral association, which was owing merely to the representation of the desk. Some days before, when opening the desk, I had broken the glass of my' watch, which I held in my hand, and the fragments fell among the papers: hence no further attention was paid to the diamond, being a representation of a collateral series of things. But afterwards, the representation of the sparkling stone was again excited, and became the prevailing idea; hence it determined the succeeding association. On account of its similarity, it excited the representation of fire, with which it was confounded; hence arose fire and smoke. But, in the event, the Writings only were burned, not the desk itself; to which, being of comparatively less value, the attention was not at all directed."