any terrific impression, and most probably these alarming phantasms will be of a chimerical and an extravagant nature. A man who has been bitten by a dog may fancy himself in the coils of a boa-constrictor. When dreaming, the mind is in an abstracted state; but still is its reciprocal influence over the body manifest, although it is powerless on volition. Vigilance in sleep is still awake; but her assistance is of no avail until the connexion between mind and body is aroused by any alarm from external agents. It is well known that a hungry man will dream of an ample repast. A patient with a blister on his head has fancied himself scalped by Indians in all their fantastic ornaments. Somnambulism clearly proves that the mind retains its energies in sleep. Locke has justly observed that dreams are made up of the waking man's ideas, although oddly put together. Hartley is of opinion that dreams are nothing but the reveries of sleeping men, and are deducible from the impressions and ideas lately received, the state of the body, and association. I have endeavoured to explain, on the ground of the general effects of predisposition, the anomalies which so often are displayed in these associations. Of the surprising powers of the mind in somnambulism we have many instances too well authenticated to be doubted. Henricus ab Heeres was in the habit of composing in his sleep, reading aloud his productions, expressing his satisfaction, and calling to his chamber-fellow to join in the commendation. Caelius Rhodiginus when busied in his interpretation of Pliny, could only find the proper signification of the word _ectrapali_ in his slumbers. There is not the least doubt but that the mind is capable of receiving impressions of knowledge, but more particularly inspirations of genius, when the body is lulled in a state of apparent repose. Dreams have been ingeniously compared to a drama defective in the laws of unity, and unconnected by constant anachronisms. Yet certain incoherences are not frequent: Darwin has justly remarked that a woman will seldom dream that she is a soldier, and a soldier's visions will seldom expose him to the apprehensions of child-birth. Buffon has observed, "We represent to ourselves persons whom we have never seen, and such as have been dead for many years; we behold them alive and such as they were, but we associate them with actual things, or with persons of other times. It is the same with our ideas of locality; we see things not where they were, but elsewhere, where they never could have been."