We have already seen an instance of a somewhat similar character, in the account given in a previous paper of the apparition of a father, then alive, but absent at church, to his daughter at home. In that case the apparition was excited by the sight of the arm-chair generally occupied by the old gentleman, and connected with it alone, the association of the ideas being obvious; and the state of the brain forming, so to speak, the substratum of the hallucination, was induced by uneasiness caused by a heavy thunder-storm acting on a frame debilitated by fever.

The apparition of the following night, which was seen also by Professor Oeder, was, so far as M. Hoefer was concerned, a modification of the hallucination of the preceding night, prompted by the belief that the apparition he had witnessed was supernatural; and the precise similarity of the apparition professed to have been seen by M. Oeder, to that seen by M. Hoefer on that and the preceding night, would lead to the suspicion that in the former gentleman it was a trick of the imagination alone,—a suspicion confirmed by the subsequent progress of the tale.

Professor Oeder brooded upon the apparition he had witnessed, and, it is important to mark, made every endeavour for some time to obtain a second sight of it, but failed, until wearied out with his fruitless research, he ceased to hunt after it. Fourteen days afterwards, he states that he was suddenly and rudely awakened "by some external motion" (which is evidently an after-conclusion derived from what followed), and saw the apparition of Doerien standing by the clothes-press.

In other words, he awoke suddenly out of a troubled sleep, and in the transition state between sleeping and waking, in which the mental images are as bright and defined as in dreams, the subject which had occupied his mind so much of late was presented before him in a visible form. As it not unfrequently happens when a dream has made a powerful impression on the mind, it is repeated again, so on the following night M. Oeder's hallucination occurred, but with the addition of a slight creaking noise of the clothes-press door.

Oeder was now fully convinced of the supernatural character of his visitant, and when the spectre again appeared to him, which was after a period of eight days, he having adopted the opinion at that period very prevalent, of troubled spirits, proceeded to inquire as to the cause of its visitations; and noticing a white tobacco-pipe in the spirit's mouth, and knowing that the deceased Doerien had "left some debts to the amount of a few dollars," he asked, "Are you perhaps owing for tobacco?" whereupon the spirit disappeared. Here then we find an hallucination, either in the dreaming or waking state, presenting the precise similitude of the Professor's opinions and conceptions respecting the possible cause of the spectre.

The following night, when the spectre appeared again, a friend was with Oeder, but this friend saw "nothing further than something white,"—no very extraordinary sight in a room which had white walls, and was not perfectly dark.

From this time Oeder used a night-lamp, and the spectre no more appeared, but by certain sensations and noises he knew it was in the apartment.

The invisibility of the spectre, when the light was present, would indicate that a sensation of light excited in the eye by a disordered state of the head, such as we have fully dwelt upon in a previous part of the work, played an important part of the hallucination; and the disturbed sleep for so many nights, and uneasy sensations, point to a circumstance which we have not yet alluded to, that the Professor's health was not in good condition,—the probable cause of the whole series of hallucinations.

The uneasy sensations ceased, the light was dispensed with, the spectre again came, but it was darker, and contained a new sign in its hand, which, by following out a similar course of reasoning as upon the tobacco-pipe, and by long ruminating and inquiring, the Professor puzzled out to signify some paintings belonging to a magic lantern which Doerien had received on trial before his death, and which had not been returned. They were sought up, sent to their rightful owner, and the apparition vanished to return no more.

It is to be remembered that this story, like most others of a similar nature, has been written under a full belief of the supernatural character of the apparitions, and it has received a colouring accordingly; and our comments suffice to show that no care, no attempt, has been made by the ghost-seer, to ascertain how much the apparitions might depend upon some illusion or hallucinations connected with his bodily health. The progress of the tale further shows that the apparitions occurred, in both M. Hoefer as well as Professor Oeder's case, in connection with symptoms of disordered health, and that they added nothing to what these gentlemen knew, or could work out, as M. Oeder did, by his own reason and judgment; in short, that they were simple images of ideas they already possessed or arrived at from the information they obtained.