"It possesses the likeness of the person whom we wished to see, only the visage is of an ashy paleness.
"On approaching the figure, one is conscious of a resistance, similar to that which is felt when going against a strong wind, which drives one back.
"If one speaks with it, one remembers no more distinctly what is spoken; and when the appearance vanishes, one feels as if awakening from a dream. The head is stupified, and a contraction is felt about the abdomen. It is also very singular that the same appearance presents itself when one is in the dark, or when looking upon dark objects.
"The unpleasantness of this sensation was the reason why I was unwilling to repeat the experiment, although often urged to do so by many individuals."[67]
It would be difficult to conceive any more powerful method of inducing hallucinations than that detailed in this instructive and interesting recital. The previous schooling of the imagination, in order thoroughly to imbue it with the train of ideas requisite for the full development of the phenomenon, and the subsequent intoxication induced by the inhalation of powerful narcotic vapours—an intoxication which, as we have already seen in the example of haschish, is peculiarly apt to the development of hallucinations—will sufficiently account for the illusion of the smoke of the chafing-dish presenting any figure which the mind desires to see. The difficulty which the experimenter experienced in approaching the phantom, and which he compares to the resistance which is felt when contending against a strong wind, was evidently due to the powerful emotion which he experienced depriving him of that control of the voluntary muscles, such as we find in a person paralyzed by fear or astonishment; or perhaps it was rather a feeling similar to that experienced in nightmare, when, whatever effort we may make, we feel almost incapable of motion.
The action of the narcotic vapour alone was sufficient to induce hallucinations; for, persuaded by a very experienced physician, who "maintained that the narcotic ingredients which formed the vapour must of necessity violently affect the imagination, and might be very injurious, according to circumstances," Eckhartshausen made the experiment on himself without previous preparation; "but," he writes, "scarcely had I cast the quantum of ingredients into the chafing-dish, when a figure presented itself. I was, however, seized with such a horror, that I was obliged to leave the room. I was very ill during three hours, and thought I saw the figure always before me. Towards evening, after inhaling the fumes of vinegar, and drinking it with water, I was better again; but for three weeks afterwards I felt a debility: and the strangest part of the matter is, that when I remember the circumstance, and look for some time upon any dark object, this ashy pale figure still presents itself very vividly to my sight. After this I no longer dared to make any experiments with it."
The use of intoxicating and stupifying drugs doubtless contributed also to the development of those ideas of strange and wonderful transformations and anomalies of form with which the legends and romances of Oriental and European nations teem. In the examples of hallucinations we have already given from this source, we find the key to the explanation of several of these transformations; and the elaborated supernatural framework of fairy tales, in which men are changed without compunction into inferior animals, trees, or vegetables, has probably had a similar origin.
The state of "clairvoyance," and that condition of the nervous system which is found in certain diseases, dreams, and under the influence of narcotic poisons, in which, by suggestions, in whatever manner given, certain actions and trains of thought may be excited at the will of the suggestor, is seen also, and may be induced at will in those conditions of the system which are summed up under the terms "mesmerism," "animal magnetism," "electro-biology," &c.; and the theories which have been invented to explain them, and which are expressed in the above names, are not only needless, but inconsistent with the facts observed. The so-called mesmeric and electro-biological trance is strictly allied to certain forms of dreaming; and the whole of the results witnessed may be explained by certain admitted physiological and physical laws of action, and are due to leading trains of thought which are excited by suggestions direct or indirect. As to the higher faculty of prevision claimed in this state, we are not aware that, as yet, a single trustworthy instance has been established.
There is a class of spectral apparitions which differ from those which we have already dwelt upon, inasmuch as they have appeared to foreshadow, or have occurred coincidently with, the death of an individual; or they have made known events occurring at a distance, or have brought to light things else hidden by the grave.