"Ah, my friend, Sanders Screw hath another which doth the very same."

"Indeed! thou amazest me," said the physician, resting his bearded chin on his staff. "John of Gaddesden's collar was an anodyne necklace, and had the word abracadabra written thereon."

"But the collar of Carle Sanders is only a stout cord," said the advocate, with a sardonic grin.

"I blush, Sir Adam, that thou shouldst name this vile worm in the same breath with John of Gaddesden," said the physician, indignantly, as he arose and grasped his sand-glass; "a man whose virtues shone bright as the rays of Acarnan—the star of Eridanus. Ah! he was a fortunate man, that John of Gaddesden; he was born when Astroarch, queen of the planets, was shining in all her glory in Abdevinam—the head of the twelfth mansion; while I, unhappy! was born, as I have discovered by the aid of my new astrolabe, on a night of storms."

"Thou hast brought back my poniard, I hope?"

"It is here," replied the visitor, taking a dagger from his belt; "the contents of this cause death within two hours after they are taken."

"Two hours?"

"He who imbibes them," he continued, in a low voice, "falleth down senseless, lifeless, and dies without a groan—suddenly as if shot with a hand-gun. Sir Michael Scott had this secret of a learned clerk at Salamanca, whither he rode in one night, and ere daybreak was again at his castle of Balwearie."

"There is a powder, too—zounds! I had well nigh forgot it: 'the sleeping powder.'"

"'Tis here," replied the physician, taking a packet from the pocket that hung at his girdle; "this was first prepared for a caliph of the East, by Geber, the learned Arabian astrologer, who flourished in the eighth century, and whose three works on chemistry were published at Strasbourg seventeen years ago, that is, in 1520."