Or suppose a superstitious person passing, in the obscurity of the night, a place where some foul crime had been perpetrated. Terror gives rise to the production of a vivid sensation of light in the field of vision, and the imagination, as in the previous case, works out the rest.
The following cases are examples of the influence which the spontaneous appearance of light in the field of vision exercises in the development of spectral apparitions.
A gentleman who had lost his wife from a painful and protracted disease, for some time subsequently was troubled by her phantom, which remained before his eyes so long as he was in obscurity. On a light being brought, or during the day, this spectre vanished, but no sooner was he placed in darkness than it appeared vividly limned before him, and was a source of constant terror.[60]
This phantom was evidently due to the production of the sensation of light in the field of vision, and the subsequent effects of the imagination.
A gentleman with whom we are acquainted happened, when young, to have a severe fall on the head. After this accident and until he attained the age of eleven years, he was subject to visions of brilliant and variously coloured light, when he retired to bed at night, and all light in his room had been extinguished. Occasionally these visions were so gorgeous and resplendent that he is accustomed to compare them to the jewelled decorations of the palaces of the genii in the Arabian Nights' Entertainment. When about eleven years of age he got possession of a volume of legends and romances, which were pregnant with supernatural events and personages; and a friend injudiciously gave him a work full of ghost-stories, and entitled, "News from the Invisible World." These works he read with avidity, and the effect upon the mind was such that henceforth his nightly visions were transformed into foul, horrid, and often variously coloured spectres, rendering the period of time intervening between retiring to rest and sleep, one of unmitigated terror, and it became necessary to have a light constantly burning in the room until sleep occurred. After the twelfth year the intensity of the visions rapidly diminished, and at length only occurred when he turned himself upon his face in bed. In this position a sensation as if the bed had passed from under him occurred, and his eye formed the centre of a circle of imps which whirled rapidly round it. The number of these spectres next began to diminish, and by the time he was fifteen years of age, but one remained, and this appeared only occasionally. This solitary spectre gradually lost its fiend-like form, and assumed that of a respectable-looking old Roman, clothed in a toga; and it at length vanished to re-appear no more.
This gentleman has for many years been free from any spectral apparition; but hard study, mental emotion, a disordered state of the health, or pressure with the finger on the eyeball, is apt to occasion a brilliant evolution of coloured light in the field of vision.
The spontaneous appearance of light in the visual field, in this case, formed the substratum upon which the mind moulded the spectres; and it is interesting to remark the influence which the perusal of a volume of legends and ghost-stories, and subsequent classical studies, had in determining the form of the phantasma.
To the same cause—the subjective phenomena of vision—are due the various coloured lights or luminous appearances which, in the experiments of Reichenbach, the believers in animal magnetism, mesmerism, and electro-biology, are supposed to have been seen issue, by the "susceptible," from the poles of magnets placed in darkened apartments, from so-called magnetised bodies, or from bodies placed in the conditions which the respective theories demand.
All the sensations of light that are experienced under these circumstances, and which have been sought to be explained by the assumption of the "od" force, or by the influence of magnetism, &c., are dependent on that excitation of a sensation of light in the eye when plunged into darkness, or when under certain mental emotions which we have fully explained.