# The wonders of optics/Spectres

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SPECTRES—THE GHOST ILLUSION.
We close our account of the wonders of optics by a description of the ghost illusion, which has been exhibited with such great success by M. Robin, the well-known French conjurer, Mr. Pepper, the enterprising manager of the Royal Polytechnic Institution, and several others. Before doing so, however, we will say a few words on those unpleasant visitations known as spectres, to which some people are liable, either through an over-worked brain or some organic disease.
The peculiar appearances known as spectres in optics are certain illusions of vision in which an object is apparently presented to the view which does not really exist. In such cases either the brain, the retina, or the optic nerve are unnaturally excited, and made sensitive to an appearance that, physically speaking, does not exist. There is such a close connexion between the senses and the mind, that we continually, and without knowing it, transfer to the physical world that which belongs to the domain of thought. A picture which has struck us during the day will reappear to us at night during sleep, with every detail perfect, or possibly under a form modified by the capricious wanderings of our thoughts. A sudden fright may sometimes be the cause of optical illusions which will pursue us unceasingly. Fear, despair, passion, ambition, and other violent men-​tal phases, are capable of evoking images closely connected with the state of our brain, appearances that we often take for realities, and whose truths we have to test by our faculty of reasoning, before we can set them down as positive illusions. "In the most insignificant phenomena," says Sir David Brewster, "we find that the retina is so powerfully influenced by exterior impressions as to retain the images of visible objects for a long time after they have passed out of sight; besides, this portion of the eye is so strongly influenced by local impressions of which we know neither the nature nor the origin, that we see the shapeless forms of coloured light moving about in the dark. In fact we have, in the cases of Newton and many others, examples of the ease with which the imagination revivifies the images of luminous objects for months or even years, after these impressions took place. After the occurrence of such phenomena, the mind can readily comprehend how thin is the division that separates reality from those spectral illusions which during a particular state of health have afflicted the most intelligent men, not merely those belonging to the community at large, but also the most learned philosophers."
Spectres may properly be divided into two classes, those which may be termed subjective, which result from some unnatural action of our minds or bodies, and which properly belong to the science of physiology, and those which may be called objective, which are caused by some peculiar illusion acting on us from without. We shall pass lightly over the first, illustrating them by a single example, while we shall pay more serious attention to those belonging to the second class.
Sir Walter Scott, in his Letters on Demonology and Witchcraft, mentions a remarkable instance of the first order of spectres. A doctor of eminence was called in to attend a gentleman who occupied a high place in a ​particular department connected with the administration of justice. Until the time that the physician's services became necessary, he had shown strong common sense and extraordinary firmness and integrity in every case in which he had been called upon to arbitrate. But after a certain epoch his temper became saddened, although his mind preserved its habitual strength and calmness. At the same time, the feebleness of his pulse, the loss of appetite, and impaired digestion seemed to point out to his medical adviser the existence of some serious source of disturbance. At first the sick man seemed inclined to keep the cause of the change in his health a profound secret; but his melancholy bearing, confused answers, and the badly disguised constraint with which he sharply replied to the interrogations of the doctor, caused the latter to seek for information as to the cause of the disorder in other directions. He made minute inquiries of the various members of his unhappy patient's family, but he could obtain no explanation of the mystery. Every one was lost in conjecture as to the reason of the alarming condition of the patient, which did not appear to be justified by any loss of fortune or beloved friends. His age rendered the idea of an unsuccessful love affair improbable, and his known integrity precluded the possibility of remorse. The doctor accordingly was compelled to return once more to the straight road, and he used the most serious arguments with his patient to induce him to conquer his obstinacy. At last the doctor's efforts took effect; the patient allowed himself to be convinced, and manifested his desire to open his mind frankly to the doctor. They were accordingly left alone, all the doors were securely fastened, and the patient made the following singular avowal.
"You cannot be more firmly convinced, my dear friend, than I am myself, that I am on the eve of death, crushed by the fatal malady which has dried up the ​sources of my life. You remember, without doubt, the disease of which the Duke of Olivarez died in Spain?"
"From the idea," replied the doctor, "that he was pursued by an apparition in whose existence he did not believe, and he died from the continual presence of this imaginary vision weighing down his strength, and breaking his heart."
"Well, my dear doctor," the patient went on, "I am in the same condition, and the presence of the vision that persecutes me is so painful and frightful, that my reason is totally helpless in controlling the effects of my imagination, and I feel that I am dying from the effects of an imaginary illness. My visions began two or three years since. At first I found myself embarrassed from time to time by the presence of a great cat, which appeared and disappeared I knew not how. But at last the truth flashed across my mind, and I was compelled to look upon the creature, not as an ordinary domestic animal, but as a vision which had its origin in some derangement of the organs of sight or in my imagination. I have no antipathy to cats, in fact I am rather fond of them, so I endured the presence of my imaginary companion so well that at last I treated the whole affair with indifference. But at the end of several months the cat disappeared, and was replaced by a spectre of greater importance, and whose exterior was, to say the least of it, very imposing. It was neither more nor less than one of the high officials of the House of Lords, in the full dress belonging to his dignity.
"This personage, who was in court dress, with a bag-*wig on his head, and a sword by his side, his coat splendidly embroidered and his chapeau bras under his arm, glided along by my side like a shadow. Whether I was in my own house or elsewhere, he mounted the stairs before me, as if to announce my coming. Sometimes he seemed to mix with the company, although it was evident ​that no one remarked his presence, and I was the sole witness of the chimerical honours that this imaginary individual seemed to render to me. This phantasy of my brain did not make a very strong impression on me, although it made me conceive doubts as to the state of my health, and the effects it would produce upon my reason.
"This second phase of my malady, like the first, also came to an end. Some months after, the usher of the Upper House ceased showing himself, and he was replaced by an apparition that was at once wearing to the mind and terrible to the sight. It was a skeleton. Whether I was alone or in company this frightful image of death never quitted me; it dogged my footsteps and followed me everywhere, and seemed to be a shadow inseparable from myself. It was in vain that I repeated to myself a hundred times over that the vision was not real, and was only an illusion of my senses. The reasoning of philosophy and my religious principles, strong though they are, are powerless to triumph over the influence that besets me, and I feel that I shall die a victim to this cruel evil."
"It seems then," interrupted the doctor, "that this skeleton is always before your eyes?"
"It is my evil fate to see it continually before me."
"In which case it is at this moment visible to your eyes?"
"It is at present."
"And in what part of the room do you imagine that you see it now?" asked the doctor.
"At the foot of my bed," replied the patient: "when the curtains are half open I can see it place itself in the empty space between them."
"You say that you are convinced that it is only an illusion," replied the doctor; "have you the firmness to convince yourself of it positively? Have you the necessary ​
Fig. 72.—The Spectre. An optical illusion.
position which appears to be occupied by the spectre, in order to demonstrate to yourself positively that it is only a vision?"
The unfortunate man sighed and shook his head.
"Well," went on the doctor, "let us try another plan."
He quitted the chair on which he was sitting, at the head of his patient's bed, and placing himself between the half opened curtains, in the place where the patient had pointed out the skeleton, he asked if the apparition was still visible.
"Not the whole of it," answered the patient, "because you are standing between him and me; but I see his skull looking at me over your shoulder."
In spite of his philosophy, the learned physician could not help starting to hear that the spectre was immediately behind him. He had recourse to other questions, and tried endless remedies, but without success. The prostration of the patient, however, increased, and he died in the same distress of mind in which he had passed the last months of his life. This example is a sad proof of the power of the imagination over the life of the body even when the terrors endured are powerless in destroying the judgment of the unfortunate sufferer. We will say more; men who have the strongest nerves are not free from similar illusions.
The second kind of spectres, in which the science of optics plays so important a part, is the result of the imagination being deceived by art with the assistance of science.
These spectres are displayed in the ghost trick which has been practised at various Parisian theatres for a number of years, with very great success, more especially at the Théâtres du Châtelet and Dejazet. The Adelphi, in London, also employed Mr. Pepper to heighten the ​ effect of the excellent acting of Mr. Toole and Mrs. Alfred Mellon, in the dramatic version of Dickens' "Haunted Man," by the introduction of various spectral effects. And the same trick was also called into requisition with some success in several of the minor theatres in New York and other cities of the United States. At the Polytechnic, in London, very remarkable effects were produced, and few who ever saw them will forget the surprise they felt at seeing the first representation of an imponderable ghost endowed with motion, and even speech. Amongst the most successful productions in this way was the entertainment of M. Robin, one of the cleverest of the many successors of the great Robert Houdin, the prince of prestidigitators. M. Robin claims to be the inventor of the ghost illusion, and to have shown it frequently since 1847. Whether this be so or not it is not our business to decide, but we can testify that his exhibition in the Boulevard du Temple drew all Paris to see it. Evening after evening he not only "called spirits from the vasty deep," but "made them come." He pierced them with swords, he fired pistols through them, and he made them appear and disappear at his slightest wish. He showed the Zouave at Inkermann, lying dead amongst a heap of slain, who at the familiar sound of the drum, rose, pale and grave, and showed the bleeding wounds from which he died. Amongst other scenes shown by M. Robin was one of a spectre appearing to an armed man, who after trying in vain to shut out the vision from his sight fires a pistol at the intruder. Fig. 72 shows the scene as seen by the audience, and fig. 73, the method by which the illusion is worked. The theatre is shown in section. On the left, at the end, are seen the spectators; on the right is the stage upon which the scene is represented. Beneath the stage is an actor clothed in white to personate a ghost, whose image is reflected by the glass above. ​
Fig. 73.—How to produce Spectres.
of the front of the stage, the edges being carefully concealed by curtains. The glass of course must be of a very large size, and should be of the very best quality, so that it cannot be seen by the audience. The actor must take care to place himself in such a position as to counteract the effect produced by the glass being placed at an angle. At first the cavalier is seen sitting at a table. After soliloquizing for a time in a very remorseful manner touching several murders that he has committed, the ghost of one of his victims gradually appears. This is effected by gently turning the electric light upon the concealed actor. The murderer and victim parley for a short time, when the former, being unable to withstand the reproaches of the ghost any longer, fires a pistol at him point-blank. The ball of course takes no effect, so the villain draws a sword, but before it has left its scabbard the spirit of the victim has vanished with a mocking laugh, or, in other words, the electric light is suddenly turned off. The management of the light is exceedingly difficult under these circumstances; the theatre, the stage, and the portion beneath ought to be lighted in a very careful manner, for if either is too bright or too dark it mars the whole effect. It must be remembered, too, that the person performing the part of the spectre and the real actor above cannot see each other, consequently all their action has to be carried on by guess-work. The actor below has to walk along an inclined plane, keeping himself exactly at right angles to it. Again, the movements of the latter are obliged to be reversed; for the cavalier already mentioned drew his sword with his left hand in order that the reflected figure should appear to use the right.
When well arranged, the ghost trick leaves far behind all the efforts of a similar nature that were obtained by the ancients in the way of magical illusions. It is also ​incontestably true, contrary to what some people have supposed, that they were unable to perform this illusion in the way we have described, for they were ignorant of the method of manufacturing and polishing glass plates of sufficient size and clearness for the purpose.
The production of living but impalpable spectres is thus a completely modern achievement, as we have already proved, and which has taken its place amongst the applications of science to stage art, to the total exclusion. of all effects depending for their production on the old-fashioned phantasmagoria and magic lantern.
THE END.