When Martin Ker, the husband of Dame Josserande, died, their son Sylvestre was only seven years old. The widow was obliged to give up the guardianship of the great door to a man-at-arms, and retire to the tower, which was her inheritance; but little Sylvestre Ker had permission to follow the studies in the convent school.
The boy showed natural ability, but he studied little except in the class of chemistry, taught by an old monk named Thaël, who was said to have discovered the secret of making gold out of lead by adding to it a certain substance which no one but himself knew; for certainly, if the fact had been communicated, all the lead in the country would have been quickly turned into gold.
As for Thaël himself, he had been careful not to profit by his secret, for Gildas the Wise had once said to him,—
"Thaël, Thaël, God does not wish you to change the work of His hands. Lead is lead, and gold is gold. There is enough gold, and not too much lead. Leave God's works alone; if not, Satan will be your master."
Most assuredly such precepts would not be well received by modern industry; but St. Gildas knew what he said, and Thaël died of extreme old age before he had changed the least particle of lead into gold. This, however, was not from want of will, which was proved after his death, as the rumor spread about that Thaël did not altogether desert his laboratory, but at times returned to his beloved labors. Many a time, in the lonely hours of the night, the fishermen, in their barks, watched the glimmer of the light in his former cell; and Gildas the Wise, having been warned of the fact, arose one night before Lauds, and with quiet steps crossed the corridors, thinking to surprise his late brother, and perhaps ask of him some details of the other side of the dreaded door which separates life from death.
When he reached the cell he listened, and heard Thaël's great bellows puffing and blowing, although no one had yet been appointed to succeed him. Gildas suddenly opened the door with his master-key, and saw before him little Sylvestre Ker actively employed in relighting Thaël's furnaces.
St. Gildas was not a man to give way to sudden wrath; he took the child by the ear, drew him outside, and said to him, gently,—
"Ker, my little Ker, I know what you are attempting and what tempts you to make the effort; but God does not wish it, nor I either, my little Ker."
"I do it," replied the boy, "because my dear mother is so poor."
"Your mother is what she is; she has what God gives her. Lead is lead and gold is gold. If you go against the will of God, Satan will be your master."