Virdow had arisen and been to town when Edward made his appearance late in the morning. After tossing on his pillow all night, at daylight he had fallen into a long, dreamless sleep.

Gerald was looking on, and the professor was arranging an experimental apparatus of some kind. He had suspended a metal drum from the arch of the glass-room by steel wires, and over the upper end of the drum had drawn tightly a sheet of rubber obtained from a toy balloon manufacturer. In the base of this drum he inserted a hollow stem of tin, one end of which was flared like a trumpet. The whole machine when completed presented the appearance of a gigantic pipe; the mouthpiece enlarged. When Edward came in the German was spreading upon the rubber surface of the drum an almost impalpable powder, taken from one of the iron nodules which lay about on the surrounding hills and slightly moistened.

"I have been explaining to Gerald," said Virdow, cheerily, "some of my bases for hopes that vibration is the medium through which to effect that ether wherein floats what men call the mind, and am getting ready to show the co-ordinations of force and increasing steadily and evenly. Try what you Americans call 'A' in the middle register and remember that you have before you a detective that will catch your slightest error." He was closing doors and openings as he spoke.

Edward obeyed. Placing his mouth near the trumpet opening he began. The simple note, prolonged, rang out in the silent room, increasing in strength to a certain point and ending abruptly. Then was seen a marvelous thing; animated, the composition upon the disk rushed to the exact center and then tremulously began to take definite shape. A little medallion appeared, surrounded by minute dots, and from these little tongues ran outward. The note died away, and only the breathing of the eager watchers was heard. Before them in bas-relief was a red daisy, as perfect, aye, more nearly perfect, than art could supply. Gerald after a moment turned his head and seemed lost in thought.

"From that we might infer," said Virdow, "that the daisy is the 'A' note of the world; that of it is born all the daisy class of flowers, from the sunflower down—all vibrations of a standard."

Again and again the experiment was repeated, with the same result.

"Now try 'C,'" said the German, and Edward obeyed. Again the mass rushed together, but this time it spread into the form of a pansy. And then with other notes came fern shapes, trees and figures that resembled the scale armor of fish. And finally, from a softly sounded and prolonged note, a perfect serpent in coils appeared, with every ring distinctly marked. This form was varied by repetition to shells and cornucopias.

So through the musical scale went the experiments, each yielding a new and distinct form where the notes differed. Virdow enjoyed the wonder of Edward and the calm concentration of Gerald. He continued:

"Thus runs the scale in colors; each of the seven—red, orange, yellow, green, blue, indigo and violet—is a note, and as there are notes in music that harmonize, so in colors there are the same notes, the hues of which blend harmoniously. What have they to do with the mind memory? This: As a certain number of vibrations called to life in music the shell, in light the color, and in music the note, so once found will certain notes, or more likely their co-ordinations, awaken the memories of the mind, since infallibly by vibrations were they first born.

"This is the border land of speculation, you think, and you are partly correct. What vibration could have fixed the form of the daisy and the shape we have found in nature is uncertain, but remember that the earth swings in a hollow drum of air as resonant and infinitely more sensitive than rubber; and the brain—there is a philosophic necessity for the shape of a man's head."

"If," said Gerald, "you had said these vibrations awakened the memories of the brain instead of the mind, I could have agreed with you. Yours are on the order of the London experiments. I am familiar with them, but only through reading." Again Virdow wondered, but he continued:

"The powers of vibration are not understood—in fact, only dreamed of. Only one man in the world, your Keely, has appreciated its possibilities, and he is involved in the herculean effort to harness it to modern machinery. It was vibration simply that affected Gerald so deeply last night; a rhythm co-ordinating with his heart. I have seen vast audiences—and you have, too, Edward—painfully depressed by that dangerous experiment of Mendelssohn; for the heart, like a clock, will seek to adjust itself to rhythms. Your tempo was less than seventy-two to the minute; Gerald's delicate heart caught time and the brain lacked blood. A quick march would have sent the blood faster and brought exhilaration. Under the influence of march time men cheer and do deeds of valor that they would not otherwise attempt, though the measure is sounded only upon a drum; but when to this time is added a second, a third and a fourth rhythm, and the harmonies of tone against tone, color against color, in perfect co-ordination, they are no longer creatures of reason, but heroes. The whole matter is subject to scientific demonstration.

"But back to this 'heart-beat march.' The whole nerve system of man since the infancy of the race has been subject to the rhythm of the heart, every atom of the human body is attuned to it; for while length of life, breadth of shoulders, chest measure and stature have changed since the days of Adam we have no evidence that the solemn measure of the heart, sending its seventy-two waves against all the minute divisions of the human machine, has ever varied in the normal man. Lessen it, as on last night, and the result is distressing. And as you increase it, or substitute for it vibrations more rapid against those myriad nerves, you exhilarate or intoxicate.

"But has any one ever sent the vibration into that 'viewless vinculum' and awakened the hidden mind? As our young friend testifies, yes! There have been times when these lower co-ordinations of song and melodies have made by a momentary link mind and matter one, and of these times are born the world's greatest treasures—jewels wrested from the hills of eternity! What has been done by chance, science should do by rule."

Gerald had listened, with an attention not hoped for, but the conclusion was anticipated in his quick mind. Busy with his portfolio, he did not attend, but upon the professor's conclusion he turned with a picture in his hand. It was the drawing of the previous night.

"What is it?" he asked.

"A mind picture, possibly," said Virdow.

"You mean by that a picture never impressed upon the brain, but living within the past experience of the mind?"

"Exactly."

"And I say it is simply a brain picture transmitted to me by heredity."

"I deny nothing; all things are possible. But by whom? One of those women?" Gerald started violently and looked suspiciously upon his questioner. Virdow's face betrayed nothing.

"I do not know," said Gerald; "you have gaps in your theory, and this is the gap in mine. Neither of these women could have seen this picture; there must have been a third person." Virdow smiled and nodded his head.

"And if there was a third person he is my missing witness. From him comes your vision—a true mind picture."

"And this?" Gerald drew from the folio a woman's face—the face that Edward had shown, but idealized and etherealized. "From whom comes this?" cried the young man with growing excitement. "For I swear to you that I have never, except in dreams, beheld it, no tongue has described it! It is mine by memory alone, not plucked from subtle ether by a wandering mind, but from the walls of memory alone. Tell me." Virdow shook his head; he was silent for fear of the excitement. Gerald came and stood by him with the two pictures; his voice was strained and impassioned, and his tones just audible:

"The face in this and the sleeper's face in this are the same; if you were on the stand to answer for a friend's life would you say of me, this man descends from the kneeling woman?" Virdow looked upon him unflinchingly.

"I would answer, as by my belief in God's creation, that by this testimony you descend from neither, for the brain that held those pictures could belong to neither woman. One could not hold an etherealized picture of her own face, nor one a true likeness of her own back." Gerald replaced the sheets.

"You have told me what I knew," he said; "and yet—from one of them I am descended, and the pictures are true!" He took his hat and boat paddle and left them abruptly. The portfolio stood open. Virdow went to close it, but there was a third drawing dimly visible. Idly he drew it forth.

It was the picture of a white seagull and above it was an arch; beyond were the bending trees of the first picture. Both men studied it curiously, but with varying emotions.