The seizure mostly comes on during common sleep. But it may supervene in the daytime; in which case the patient first falls into the lightest form of trance-sleep. After a little, still lost to things around him, he manifests one or more of three impulses: one, to speak, but coherently and to a purpose; a second, to dress, rise, and leave his room with an evident intention of going somewhither; a third, to practise some habitual mechanical employment. In each case he appears to be pursuing the thread of a dream. If he speaks, it is a connected discourse to some end. If he goes out to walk, it is to a spot he contemplates visiting; his general turn is to climb ascents, hills, or the roofs of houses: in the latter case he sometimes examines if the tiles are secure before he steps on them. If he pursues a customary occupation, whether it be cleaning harness or writing music, he finishes his work before he leaves it. He is acting a dream, which is connected and sustained. The attention is keenly awake in this dream, and favours its accomplishment to the utmost. In the mean time the somnambulist appears to be insensible to ordinary impressions, and to take no cognisance of what is going on around him—a light maybe held so close to his eyes as to singe his eyebrows without his noticing it—he seems neither to hear nor to taste—the eyelids are generally closed, otherwise the eyes are fixed and vacant. Nevertheless he possesses some means of recognising the objects which are implicated in his dream; he perceives their place, and walks among them with perfect precision. Let me narrate some instances. The first, one of day-somnambulism, exemplifies, at the same time, the transitions to full waking, which manifest themselves occasionally in the talking form of the trance. The case is from the _Acta Vratisv._ ann. 1722. A girl, seventeen years of age, was used to fall into a kind of sleep in the afternoon, in which it was supposed, from her expression of countenance and her gestures, that she was engaged in dreams that interested her. (She was then in light trance-sleep, initiatory trance.) After some days she began to speak when in this state. Then if those present addressed remarks to her, she replied very sensibly, but then fell back into her dream discourse, which turned principally upon religious and moral topics, and was directed to warn her friends how a female should live—Christianly, well governed, and so as to incur no reproach. When she sang, which often happened, she heard herself accompanied by an imaginary violin or piano, and would take up and continue the accompaniment upon an instrument herself. She sewed, did knitting, and the like. She imagined, on one occasion, that she wrote a letter upon a napkin, which she folded for the post. Upon waking, she had not the slightest recollection of any thing that had passed. After a few months she recovered. The following case is from the Hamburgh _Zeitschrift für die gesammte Medicin_, 1848:—