mposition of certain medicines, which Bacon
himself believed might be the means of prolonging life, though not to
the indefinite extent dreamed of by those who put their whole faith in
the Great Elixir.

But there never yet was an adept in any art or science who freely
communicated to his pupil the full amount of his own knowledge;
something for experience to gather, or for ingenuity to discover, is
always kept in reserve, and the instructions of Roger Bacon stopped
short at one point. He was himself engaged in the prosecution of that
chemical secret which he rightly judged to be a dangerous one, and,
while he experimented with the compound of sulphur, saltpetre, and
charcoal, he kept himself apart from his general laboratory, and wrought
in a separate cell, to which not even Hubert had access. To know that
the friar had a mysterious occupation, which, more than the making of
gold or the universal medicine, engrossed him, was enough of itself to
rouse the young man's curiosity; but when to this was added the fact,
that, from time to time, strange and mysterious noises were heard,
accompanied by bright corruscations and a new and singular odor,
penetrating through the chinks close to which his eyes were stealthily
riveted, Hubert's eagerness to know all that his master concealed had no
limit. He resolved to discover the secret, even though he should perish
in the attempt; he feared that there was good reason for the accusation
of dealing in the Black Art, which, more than all others, the monks of
Bacon's own convent countenanced, but this apprehension only stimulated
him the more. For some time Hubert waited without an opportunity
occurring for gratifying the secret longing of his heart; at last it
presented itself.

To afford medical assistance to the sick, was, perhaps, the most useful
practice of conventual life, and the monks had always among them
practitioners of the healing art, more or less skillful. Of this number,
Roger Bacon was the most eminent, not only in the monastery to which he
belonged, but in all Oxford.

It was about the hour of noon on a gloomy day toward the end of
November, in the year 1282, while the Friar and his pupil were severally
employed, the former in his secret cell, and the latter in the general
laboratory, that there arrived at the gate of the Franciscan convent a
messenger on horseback, the bearer of news from Abingdon, that Walter de
Losely, the sheriff of Berkshire, had that morning