When he was gone, quiet again reigned in the convent, and Hubert de Dreux resumed his occupation. But it did not attract him long. Suddenly he raised his head from the work and his eyes were lit up with a gleam in which joy and fear seemed equally blended. For the first time, for months, he was quite alone. What if he could obtain access to his master's cell and penetrate the mystery in which his labors had been so long enveloped! He cautiously stole to the door of the laboratory, and peeped out into a long passage, at the further extremity of which a door opened into a small court where, detached from the main edifice and screened from all observation, was a small building which the Friar had recently caused to be constructed. He looked about him timorously, fearing lest he might be observed; but there was no cause for apprehension, scarcely any inducement could have prevailed with the superstitious Franciscans to turn their steps willingly in the direction of Roger Bacon's solitary cell.
Reassured by the silence, Hubert stole noiselessly onward, and tremblingly approached the forbidden spot. His quick eye saw at a glance that the key was not in the door, and his countenance fell. The Friar's treasure was locked up! He might see something, however, if he could not enter the chamber. He knelt down, therefore, at the door, and peered through the keyhole. As he pressed against the door, in doing so, it yielded to his touch. In the haste with which Friar Bacon had closed the entrance, the bolt had not been shot. Herbert rose hastily to his feet, and the next moment he was in the cell, looking eagerly round upon the crucibles and alembics, which bore witness to his master's labors. But beyond a general impression of work in hand, there was nothing to be gleaned from this survey. An open parchment volume, in which the Friar had recently been writing, next caught his attention. If the secret should be there in any known language. Hubert knew something of the Hebrew, but nothing yet of Arabic. He was reassured; the characters were familiar to him; the language Latin. He seized the volume, and read the few lines which the Friar had just traced on the last page.
They ran thus:
"Videas tamen utrum loquar in ænigmate vel secundum veritatem." And, further (which we translate): "He that would see these things shall have the key that openeth and no man shutteth, and when he shall shut no man is able to open again."
"But the secret—the secret!" cried Hubert, impatiently, "let me know what 'these things' are!"
He hastily turned the leaf back and read again. The passage was that one in the "Epistola de Secretis" which spoke of the artificial thunder and lightning, and beneath it was the full and precise receipt for its composition. This at once explained the strange noises and the flashes of light which he had so anxiously noticed. Surprising and gratifying as this discovery might be, there was, Hubert thought, something beyond. Roger Bacon, he reasoned, was not one to practice an experiment like this for mere amusement. It was, he felt certain, a new form of invocation, more potent, doubtless, over the beings of another world, than any charm yet recorded. Be it as it might, he would try whether, from the materials around him, it were not in his power to produce the same result.
"Here are all the necessary ingredients," he exclaimed; "this yellowish powder is the well known sulphur, in which I daily bathe the argent-vive; this bitter, glistening substance is the salt of the rock, the salis petræ; and this black calcination, the third agent. But the proportions are given, and here stands a glass cucurbit in which they should be mingled. It is of the form my master mostly uses—round, with a small neck and a narrow mouth, to be luted closely, without doubt. He has often told me that the sole regenerating power of the universe is heat; yonder furnace shall supply it, and then Hubert de Dreux is his master's equal!"
The short November day was drawing to a close, when, after carefully tending the wounded sheriff, and leaving such instructions with the Abingdon leech as he judged sufficient for his patient's well-doing, Roger Bacon again mounted his palfrey, and turned its head in the direction of Oxford. He was unwilling to be a loiterer after dark, and his beast was equally desirous to be once more comfortably housed, so that his homeward journey was accomplished even more rapidly than his morning excursion; and barely an hour had elapsed when the Friar drew the rein at the foot of the last gentle eminence, close to which lay the walls of the cloistered city. To give the animal breathing-space, he rode quietly up the ascent, and then paused for a few moments before he proceeded, his mind intent on subjects foreign to the speculations of all his daily associations.
Suddenly, as he mused on his latest discovery and calculated to what principal object it might be devoted, a stream of fiery light shot rapidly athwart the dark, drear sky, and before he had space to think what the meteor might portend, a roar as of thunder shook the air, and simultaneous with it, a shrill, piercing scream, mingled with the fearful sound; then burst forth a volume of flame, and on the wind came floating a sulphurous vapor which, to him alone, revealed the nature of the explosion he had just witnessed.