"Which diffiguldy I have gombledely gonquered," triumphantly exclaimed the professor, rising excitedly from his seat with flushed cheeks and flashing eyes. "Do me, Heinrich von Schalckenberg, belongs the honour and glory of having made dwo mosd imbordand disgoveries, disgoveries of ingalgulable value do the worldt, disgoveries which will enable me do soar ad will indo the highesd regions of the embyrean, do skim the surface of the ocean, or do blunge do ids lowesd debths." "Bravo, professor; that was positively dramatic!" exclaimed the baronet. "You have mistaken your business, my dear sir; you were undoubtedly born to be an actor. But what are these two most important discoveries of which you so exultantly speak?" "They are a new medal and a new power," exclaimed the professor. Then, fumbling in his breast-pocket, he drew forth a wallet from which he extracted a small rectangular plate of--apparently--polished silver. It measured about five inches long by four inches broad, and was about a quarter of an inch thick. "There, Sir Reginald," he exclaimed, offering the plate to the baronet, "dell me whad you think of thad." "Very pretty indeed," commented Sir Reginald, as he held out his hand to take it. "What is it? Silver? Phew! No; it can't be that," as his fingers closed upon it; "it is far too light for silver. Why, it seems to be absolutely devoid of weight altogether. What is it, professor?" "Thad, my good sir, is my new medal, which I gall `_aethereum_' begause of ids wonderful lighdness. See here." There was a very handsome cut glass water-jug, full, standing on the table in a capacious salver of hammered brass. The professor took up the jug and emptied it into the salver, almost filling the latter. Then he laid the glittering slab of metal down on the surface of the water, where it floated as buoyantly as though it had been an empty box constructed of the lightest cardboard. The professor raised the salver from the table and agitated the water, to show that the metal actually floated. "Why, it floats as lightly as a cork!" exclaimed the colonel in the utmost astonishment. "Korg!" exclaimed the professor disdainfully, "korg is _heavy_ gombared with this. This is the lighdesd solid known. Loog ad this." The professor lifted the plate of metal out of the water, and, wiping it dry very carefully with his silk pocket-handkerchief, held it suspended, flat side downwards, between his finger and thumb. Then, when he had poised it as nearly horizontal as he could guess at, he let it go. It wavered about in the air as a thin sheet of paper would have done, and finally sailed aslant and very gently to the ground, amid the astonished exclamations of the beholders, by whom it was immediately examined with the utmost curiosity.