This has been demonstrated by positive experiment; for if we take any of the "susceptibles," and, indeed, others, and place them in a darkened apartment, we may by simple suggestions excite all the luminous sensations attributed to the supposititious "od" force, or to "animal magnetism."
The luminous appearances which certain "sensitives" have averred that they witnessed over graves, were due also to the subjective phenomena of vision, excited by an expectant idea.
A young clergyman named Billing, who acted as an amanuensis to Pfeffer, the blind poet, asserted that he constantly saw, at night, a luminous cloud resting in one position in the poet's garden; and on search being made beneath the surface of the ground, at the spot occupied by this phantasm, the remains of a skeleton were found.
Reichenbach concluded from this that the process of decomposition of a corpse going on in the grave, probably like what is observed in other forms of chemical action, gave rise to luminous appearances which were visible to highly "sensitive" persons.
"It appeared possible," he writes, "that such a person might see over graves in which mouldering bodies lie, something similar to that which Billing had seen. Mademoiselle Reichel had the courage, rare in her sex, to gratify this wish of the author. On two very dark nights she allowed herself to be taken from the Castle of Reisenberg, where she was living with the author's family, to the neighbouring churchyard of Grunzing. The result justified his anticipation in the most beautiful manner. She very soon saw a light, and observed on one of the graves, along its length, a delicate breathing flame; she also saw the same thing, only weaker, on a second grave. But she saw neither witches nor ghosts. She described the fiery appearance as a shining vapour, one to two spans high, extending as far as the grave, and floating near its surface. Sometime afterwards she was taken to two large cemeteries near Vienna, where several burials occur daily, and graves lie about by thousands. Here she saw numerous graves provided with similar lights. Wherever she looked she saw luminous masses scattered about. But this appearance was most vivid over the newest graves, while on the oldest it could not be perceived. She described the appearance less as a clear flame than as a dense vaporous mass of fire, intermediate between fog and flame. On many graves the flame was four feet high, so that when she stood on them it surrounded her up to the neck. If she thrust her hand into it, it was like putting it into a dense fiery cloud. She betrayed no uneasiness, because she had all her life been accustomed to such emanations, and had seen the same, in the author's experiments, often produced by natural causes."[61]
The total neglect of those precautions which are requisite to obviate the influence of expectant ideas and the subjective phenomena of vision in this experiment is most strange, and it is painful to witness men like Reichenbach, Gregory, and others, thus stumbling over some of the simplest facts of physiology and psychology, and utterly prostituting the name and calling of science.
Singular and fallacious as are the pseudo-scientific doctrines just mentioned, they are exceeded by the extraordinary speculations of other writers, who also appear to hold in utter contempt the ordinary laws of action of the senses. For example, Mrs. Crowe writes of the sensation of light perceived by somnambules and dreamers, and of the still more simple phenomenon of the sensation of light induced by the inhalation of ether, in the following manner:—
"All somnambules of the highest order,—and when I make use of this expression, I repeat that I do not allude to the subjects of mesmeric experiments, but to those extraordinary cases of disease, the particulars of which have been recorded by various continental physicians of eminence,—all persons in that condition describe themselves as hearing and seeing, not by the ordinary organs, but by some means the idea of which they cannot convey further than that they are pervaded by light; and that this is not the ordinary physical light is evident, inasmuch as they generally see best in the dark,—a remarkable instance of which I myself witnessed.
"I never had the slightest idea of this internal light till, in the way of experiment, I inhaled the sulphuric ether; but I am now very well able to conceive it; for, after first feeling an agreeable warmth pervading my limbs, my next sensation was to find myself—I cannot say in this heavenly light, for the light was in me—I was pervaded by it; it was not perceived by my eyes, which were closed, but perceived internally, I cannot tell how. Of what nature this heavenly light was—I cannot forbear calling it heavenly, for it was like nothing on earth—I know not,"[62] &c.