Part 3

"If you forget a thing, you lose just that much of yourself, don't you? When you sleep, you enter a world of dreams. In that world you think, speak, go through a set of vivid experiences. Awake, you are aware that you have had these vivid experiences--and yet, you can't possibly remember them. You are dimly conscious that you were in another world and that while there you thought, suffered, rejoiced, much in the same way that you do here. At times you have a vague feeling that you have undergone some important crisis in your dream-existence, or you wake up with the sensation of having reached some high peak of happiness. But you cannot recall the details, or even the general outlines, of what has happened. Not a scene of this dreamland, of which you are an occasional inhabitant, can you picture to your waking thought; nor does your waking memory hold the visage, or even the name, of one of your dream-associates."

"All this has to do with dreams," objected David. "It is admittedly unreal."

"Don't rely too much on old definitions. A part of you that sleeps now does experience this dream-life and finds it real. The trouble is, this dream part of you forgets; it is unable to report to the waking personality what it has seen.

"But it is not only in sleep that this dream-personality takes the place of that which we call the real self. The opium-eater inhabits a world, opened to him by his drug, and closed, even to his memory, when the effects of that drug wear off. Then, there is that curious phase of dipsomania in which the victim, apparently possessed of all his faculties, goes through actual experiences--travels, talks with people, transacts business--and when he recovers from his fit of intoxication finds it impossible to remember a single circumstance of the many known to him while under the sway of alcohol. The phenomena of hypnotism give instances of similar independent mental divisions in a single human personality. All this is the familiar material of modern psychology, out of which the scientists build strange and varied theories. I call these divided, or lost, personalities 'ghosts.'"

"Ghosts of the living, not of the dead."

"More uncanny than the old-fashioned kind," mused Una. "Fancy meeting one's own ghost!"

"Cases of such meetings are on record; Shelley's, for instance," said Leighton drily.

"The thing is strange and worth investigating. But," added David laughingly, "I am not an investigator."

"It is fascinating," declared Una emphatically. "Tell us more about it, Uncle Harold. You spoke of an experiment----"

"The experiment, by all means," said David. "Just what is it?"

"Trapping a ghost," was the laconic answer.

"And if you succeed in trapping it----?"

"Ah, then--science generally leaves its ghosts to take care of themselves. It's a good rule."

"You say you are going to trap a ghost: you don't really mean that," protested Una.

"Remember, there are two kinds of ghosts. As a scientist I am not interested in the ghosts of the dead. If they exist outside of fairy tales and theology let some one else hunt them. But I am interested in the other and more profitable kind--the ghosts of the living."

"I don't understand," said David.

"It needs explanation. Remember what I said as to the phenomena presented by the dreamer, the hypnotic subject, the dipsomaniac, the narcomaniac. In each of these cases one human mind seems capable of division into two independent halves. And each half seems to forget, or to be ignorant of the doings of its mate. Now, I am hunting for this Ghost of the Forgotten."

"Sounds romantic," remarked David. "According to your theory, don't you need a hypnotized subject--or at least a dipsomaniac--for your experiment?"

"No. The Ghost of the Forgotten lurks in all of us. The man or woman in whom this Ghost is not to be found is exceptional. I doubt if such a being exists--a being whose Book of the Past is as clear, as legible, as his Book of the Present."

"But, your experiment, Uncle," demanded Una; "show it to us."

"I need help for a satisfactory trial. An experiment isn't a picture, or a book, you know. It needs a victim of some kind. What do you say, David?" he asked, turning abruptly to him.

"You want me for the victim?" laughed David. "I'm ready. Feel just like my namesake before he tackled that husky Philistine. Tell me what I'm to do."

They were standing at the fireplace, Una with one arm through her lover's, the other resting on her uncle's shoulder. A scarcely perceptible frown clouded Leighton's features before he accepted David's offer.

"I merely want you to answer some questions," he said finally. "You will think them trivial; but I want you to answer them under unusual conditions. Let me show you my latest prize and explain things."

Leighton strode to the center of the room and thence down to that end of it where the tools of his laboratory were kept. David and Una followed, enjoying the momentary relief from the scrutiny of the old savant, who was now, apparently, engrossed in his scientific apparatus. There was not much of the latter in sight, and to the novice unfamiliar with the interior of a physicist's laboratory, and who carries away a confused impression of glass and metal jars, tubes, coils of wire, electric batteries, revolving discs, and all the nameless paraphernalia of such a place, the appointments of Harold Leighton's workshop would seem simple enough. Yet, the machine before which Leighton paused comprised one of the newest discoveries in this branch of science. Its sensational purpose was to measure and probe the mind through the purely physical operations of the body.

What appeared to be, at first glance, an ordinary galvanometer stood by itself on a table. Its polished brass frame, its flawless glass cylinder enclosing the coils of wire, recording discs and needle, suggested nothing more than the instrument, familiar to the physicist, by which an electric current is measured and tested. Connected with this galvanometer, however, was a curious contrivance consisting of a mirror, over the spotless surface of which, when the machine was in operation, a ray of light, projected from an electrified metal index, or finger, moved back and forth. The exact course of this ray of light, the twists and turns made by it in traversing the mirror, was transferred by an automatic pencil to a sheet of paper carried on a revolving cylinder. This paper thus became a permanent record of whatever experiment had been attempted.

That the subjects investigated by this unique galvanometer were human and not inanimate was indicated by two electrodes, attached by wires hanging from the machine, intended to be grasped by the hands of a person undergoing the test. Its use, also, as a detector of human thought and emotion, and not of mechanical force, was described by its name--the Electric Psychometer.

IV

THE GHOST OF THE FORGOTTEN

"Modern rack and thumbscrew," exclaimed David, eyeing curiously the machine whose gleaming surface of glass and polished metal was in striking contrast with the somber oratory.

Harold Leighton paid no heed to the comment. He was apparently too busied with some detail in the complicated mechanism before him to attend to anything else. David and Una, on the other hand, were more amused than impressed with the odd kind of entertainment chosen for this memorable evening of their betrothal by the eccentric scientist, although every now and then some unexpected bit of irony from him came disconcertingly enough.

"Why should people, whose lives are blameless, think of racks and thumbscrews when they see a simple machine like this?" he asked suddenly, taking up David's apparently unnoted exclamation. Not waiting for an answer, he went on, as if with a lecture to which they had been invited to listen.

"So far as I know this machine is the first of its kind to reach this country. It is an ingenious development of certain laws psychologists have been using for some time in their experiments, and is based on a theory that is, roughly, something like this:

"A thought is a part of the body that gives it birth. Thinking is not confined to the brain. Like the assimilation of food, it involves man's entire physical nature. In cases of exaggerated thought or emotion--intense grief, fear, joy--the physical effects are obvious. The scientist, however, claims that the physical result from a mental cause is not confined to these extreme cases. A thought, the presence of which is not perceptible in gesture, facial expression, or the slightest visible emotion, is, nevertheless, communicated physically to every part of the body. Throw a stone into a pool of water. If the stone is large, the waves caused by it can be seen until they spend themselves on the shore; if it is small, the resulting ripples become invisible long before that. The point is, the ripple exists, whether we see it or not, just as does the wave, until it has run its course.

"A thought, in its physical effect, is like the stone thrown into a pool. If it is a big, exaggerated thought, the agitation produced is outwardly visible. If it is small, more subtle, less sensational, its physical effects are invisible, although, theoretically, reaching in ripples to the extremities of the body. Hence, the psychologist's problem is: to detect and measure these invisible, intangible ripples of the mind.

"This machine, my 'ghost-hunter,' solves the problem. A Russian scientist discovered that an electric current passing through the body is affected by any abnormal physical, or nervous, activity there encountered. Thought is a form of electric impulse and would, therefore, modify any other electric force crossing its path. Hence, Tarchanoff's law. Its practical application means, the literal measurement of our mental ripples. And this is done by the psychometer."

"How?" asked David.

"It's very simple. You hold these electrodes in your hands. An electric current is turned on and passes through you. While you are thus charged with electricity, I throw the stone, the thought, into your mind. The degree, or quality, of disturbance caused by this thought modifies the electric current, the varying agitation of which is made visible by the movements of an electric finger across this mirror. From there it is recorded on the sheet of paper in this cylinder."

"What a horrible contrivance!" exclaimed Una.

"I see how it works," mused David, "except for one thing. How do you introduce the thought you want to measure?"

"If I explain that the experiment wouldn't be possible," said Leighton with a laugh. "The thought must come through unconscious suggestion, or our Ghost of the Forgotten will refuse to appear. In a way, it is like a game--and is more interesting than most games. Did you ever play the game of twenty questions?"

"I have," interjected Una. "It's this way. Something--a book, a piece of furniture, anything at all--is chosen by one set of players to be guessed by the other set. Then the set who know the secret have to answer twenty questions about it, asked by the other side. The questions sound silly, but they usually discover the secret."

"Is your experiment like Una's game?" asked David.

"Not exactly. Sit down in this chair and you'll see."

Seated as directed, the psychometer stood a little back and at one side of him.

"Now," said Leighton, giving him the electrodes, "hold these, one in each hand."

"It's like an electrocution!" exclaimed Una. "Are you very uncomfortable?"

"Oh, quite the contrary! Now, Mr. Leighton----"

"Ready? Here goes the current. You will scarcely feel it."

Leighton pulled out a small lever. A faint humming sound was heard. The electric finger on the mirror in the machine became suddenly illuminated.

"Do you feel it?" asked Una.

"Yes; it's rather nice. This hero business is all right, especially when you preside at the performance, Una."

"Now for your game of twenty questions, Uncle Harold. Of course, you are going to let me into the secret?"

"How can I?" he retorted. "David has the secret."

"I have it?" repeated the other, perplexed.

"Certainly. But this isn't exactly a game. You'll find it tedious, Una. Why not stay with Mrs. Quayle in the library until it's over?"

"Nonsense! Of course I'll stay here," she replied firmly.

"What am I to do?" asked David. "Holding these handles is easy enough--but nothing happens."

"Let me explain," said Leighton. "I am going to give you, one at a time, a number of disconnected words. As you hear each word, you must reply with the first word that suggests itself to your mind. For instance, suppose I say 'black.' The word gives rise, instantly, to some answering mental picture, and that picture will suggest a word with which your experience has associated it. Thus, when I say 'black,' you may think of 'night'; or, if your thought goes by contraries, the word 'white' may occur to you. In any case, tell me the first word that comes into your mind upon hearing my word--and remember that the promptness of your reply is an important factor in the experiment."

"It sounds easy," remarked David. "Let's begin."

On a small table at which he was standing, Leighton placed his watch, a writing-pad and pencil. Seating himself, he commenced the experiment in the way he had proposed, noting each word as he gave it on the pad before him, and marking the number of seconds elapsing before each of David's answers. Una, ensconced in a large armchair, watched the scene intently.

"Theater," was Leighton's first word.

"Music," came the prompt reply.

"Noise."

"Sleep."

"Lion."

"Teeth."

"Sound."

"Desert."

"Ocean."

"Blue."

A long series of similar question and answer-words followed, apparently chosen at random and not indicating any sequence of ideas. Leighton spoke with exaggerated monotony, his eyes fixed on David, his hand moving with mechanical precision as he jotted down the words and the time taken for each reply. Scarcely any agitation was noticeable in the finger of light upon the mirror, and this part of the experiment seemed--at least to Una--a failure.

"I don't see what the machine has to do with it," she said, somewhat puzzled. "David could just as well answer your words without holding those things in his hands."

"Una," said Leighton, giving this as the next question-word and ignoring the interruption.

David smiled, hesitated a moment before replying, while the electric finger trembled slightly and then moved, slowly and evenly, back and forth across the mirror.

"Light," he answered softly.

More question-words followed, most of them receiving prompt answers and producing no appreciable effect in the psychometer. It was noticeable, however, that words having to do with places gave a different result--a vibration of the electric finger, indicating, according to the theory, that they awakened a deeper interest than other words in David's mind.

In experiments of this kind the operator's choice of words is carefully made, as a rule, and not left to chance. They usually have a certain continuity of meaning. Theoretically, also, the operator's personality is kept in the background, so that the subject is freed from any emotional impulse save that created in him by the question-words. But there is always the possibility that this personality will unconsciously influence the subject's mind, which is thus impelled in directions it might not otherwise take. Hypnotism may thus, unintentionally, play a part in an experiment of this kind, and the subject made to follow, in the words uttered and the degree of emotion displayed, his inquisitor's suggestions.

It would be hard to tell whether hypnotism gradually came into Leighton's experiment with David. Certain it is that as the trial went on a change came over the two men. Their features grew tense, they were as vigilant to thrust and parry in this game of words as two fencers fighting on a wager whose loss would mean much to either of them. In David anxiety was more marked. The electric finger in the psychometer, unconsciously controlled by him, moved more rapidly and with greater irregularity over the face of the mirror. At times it remained fixed in one place; then, with Leighton's utterance of some new word, it would leap spasmodically forward, in a jagged line of light which would be recorded automatically on the cylinder at the back of the machine.

David could not see what was happening in the psychometer. Outwardly he showed no emotion, except the anxiety to hold his own in this word duel with Leighton. Nevertheless, the electric current passing through him registered a series of impressions that grew in variety and intensity. Theoretically, these impressions were David's thoughts and feelings acting upon the electric finger; and thus the line of light traced upon the mirror was really a picture of his own mind.

For Una the affair had lost its first element of comedy. The meaningless words, the monotonous seriousness with which they were uttered, seemed, in the beginning, a delicious bit of fooling improvised for her benefit. She delighted in the original, the unexpected, and nothing, certainly, could be more foreign to the customary betrothal night entertainment than this ponderous pairing of words between her lover and her uncle. The real purpose of the experiment had not impressed her. The talk about ghosts gave an amusing background to it; but this was afterwards spoiled, it is true, by the tedious discussion of psychological problems. Of course, Una assured herself, this experiment--or this game--was a psychological problem, and she felt certain David would solve it, whatever it might be, in the cleverest fashion.

Had Una understood from the first just what Leighton intended by his proposed "ghost-hunt" she would have followed more keenly the details of this novel pastime. As it was, these details appeared to have no intelligible object in view and failed to arouse her interest until some little time had elapsed. Then she began speculating on the meaning of her uncle's disconnected words and wondering why they drew from David just the replies they did. More to amuse herself than anything else she compared the images which these words evidently aroused in David's mind with the images suggested to her.

For "ship," he gave "sky"; she thought of "water." "Mountain" produced "tired"; she would have said "view." Her word for "river" was "rowing"; his "sunshine." He said "mystery" for "Africa"; she, "negroes." His words were never the same as hers, a fact indicating the wide differences in their individual experiences. More singular still, David's words were always remote, in meaning or association, from the question-words to which they were the answer; hers were quite the opposite. Why, she asked herself, did he say "anger" in response to "India"; "misery" to "temple"; "joy" to "ocean"; "lost" to "guide"; "slave" to "friend"?

As the experiment progressed most of her uncle's words were bound together, Una noticed, by a similarity in character. She even fancied she could detect in them the disjointed bones of a story. Most of these words had to do with foreign travel, and as David was known to have visited many countries it was natural that the test should follow this line, especially as this was a quest for the Ghost of the Forgotten. In this connection it was noticeable that the series of words chosen by Leighton reversed the itinerary which Una was certain David had followed. Thus, the first question-words indicated the English Lake region, where David had ended his travels. Then came various European countries, and after these Morocco, Egypt, Arabia, India, China, the Islands of the Pacific and the western coast of America. Supposing that Leighton had David's actual itinerary in mind, he was going over it by a series of backward steps, and had now reached a point at which, as Una remembered, the long journey began. With each backward step, also, she noted that the agitation of the electric finger in the psychometer increased. David could not see what was happening in the machine behind him, although it was his own emotions that were being recorded there. Why was he so agitated? Why did he try to hide his feelings? Why did these simple words from Leighton have such power over him? As Una asked herself these questions her sympathy for him increased, and she awaited the end of the experiment with anxiety.

Leighton paused after David matched his question-word, "California," with "home." The electric finger threw a tremulous line of light upon the recording mirror, and in both men the indifference shown when they began this strange game was lacking. The expectancy in David's face changed to defiance as "California" was followed by the question-word "ship." The electric finger gave a swift upward flash, and there was a longer pause than usual before the answer came--"storm." "Pacific" was met by "palm trees"; and these were followed by "land," "Indians"; "hotel," "strangers"; "natives," "lost"; "clew," "wealth."

With the last pair of words the agitation recorded in the psychometer reached its highest point. David's face was pale, his features drawn, his grasp on the electrodes tense. Una could not bear to witness his struggle. Although ignorant of the cause, his suffering was all too evident, and she determined to rescue him at once from her uncle's cruelty. Leighton met her appeal with characteristic coolness, ignoring her demand to bring the experiment to an end. But he changed the sequence of words he had been using.

"Homer" was the next question-word given.

The effect was immediate. David looked at the old man with astonishment. The jerky motion of the electric finger ceased, while instead an even line of light was traced over the mirror. The answer-word came promptly this time: "Iliad."

A series of similar words followed, and as the experiment took this new direction David's nervousness vanished. Then, without warning, the travel series was taken up again; and this time each word came like the blow of a hammer upon a nail that is swiftly and surely driven to its mark.

There was no mistaking the result. David's limbs stiffened, as if to ward off a blow. His look of relief gave place to a hopeless sort of misery; the telltale electric finger jumped forward in exaggerated lines as if to escape from some merciless pursuer.

"South America," demanded Leighton.

"Spaniards," after a pause, was David's answering word.

"Mountains."

"Muleback."

"Lake."

"Gold."

The answers were hesitatingly given, almost inaudible. Again Una protested.

"Stop!" she commanded. "You have no right----"

Leighton waved her imperiously aside.

"Dynamite," he continued, addressing David.

"Darkness," came the hesitating answer.

"Raoul Arthur."

Silence. A weird dance, as of some mocking spirit, seized the electric finger pointing at the mirror. Una knelt at David's side, her hands upon his shoulders. His lips quivered as he looked despairingly at her.

"Guatavita," said Leighton harshly.

No answer. The electrodes slipped from David's grasp. The finger of light became suddenly motionless.

David had fallen, unconscious, in Una's arms.

V

THE SEARCH FOR EL DORADO

"Leave him with me," said Leighton. "Wait for us with Mrs. Quayle."

"No! No!" answered the girl passionately, kneeling beside David, who was lying on the couch. "You have killed him!"

"Don't talk nonsense," he said coldly, yet with sympathy in his keen gray eyes. "This had to be, and I took my own way about it. Now, go. He is all right. He is safe with me."

David drew a long breath. He looked vacantly at Leighton, then turned to Una.

"Do as he says," he whispered.

"David, I will stay with you."

"Not now; I must speak to your uncle."

"David!"

She looked into his eyes, trying to read there the mystery that was parting them.

"It will be better for all of us," said Leighton gruffly.