The fisherman instead of answering took the lid of lead and shut it down quickly on the vase.

“Now, O genius,” he cried, “ask pardon of me, and choose by what death you will die!  But no, it will be better if I throw you into the sea whence I drew you out, and I will build a house on the shore to warn fishermen who come to cast their nets here, against fishing up such a wicked genius as you are, who vows to kill the man who frees you.”

At these words the genius did all he could to get out, but he could not, because of the enchantment of the lid.

Then he tried to get out by cunning.

“If you will take off the cover,” he said, “I will repay you.”

“No,” answered the fisherman, “if I trust myself to you I am afraid you will treat me as a certain Greek king treated the physician Douban.  Listen, and I will tell you.”

The Story of the Greek King and the Physician Douban

In the country of Zouman, in Persia, there lived a Greek king.  This king was a leper, and all his doctors had been unable to cure him, when a very clever physician came to his court.

He was very learned in all languages, and knew a great deal about herbs and medicines.

As soon as he was told of the king’s illness he put on his best robe and presented himself before the king.  “Sire,” said he, “I know that no physician has been able to cure your majesty, but if you will follow my instructions, I will promise to cure you without any medicines or outward application.”

The king listened to this proposal.

“If you are clever enough to do this,” he said, “I promise to make you and your descendants rich for ever.”

The physician went to his house and made a polo club, the handle of which he hollowed out, and put in it the drug he wished to use.  Then he made a ball, and with these things he went the next day to the king.

He told him that he wished him to play at polo.  Accordingly the king mounted his horse and went into the place where he played.  There the physician approached him with the bat he had made, saying, “Take this, sire, and strike the ball till you feel your hand and whole body in a glow.  When the remedy that is in the handle of the club is warmed by your hand it will penetrate throughout your body.  The you must return to your palace, bathe, and go to sleep, and when you awake to-morrow morning you will be cured.”

The king took the club and urged his horse after the ball which he had thrown.  He struck it, and then it was hit back by the courtiers who were playing with him.  When he felt very hot he stopped playing, and went back to the palace, went into the bath, and did all that the physician had said.  The next day when he arose he found, to his great joy and astonishment, that he was completely cured.  When he entered his audience-chamber all his courtiers, who were eager to see if the wonderful cure had been effected, were overwhelmed with joy.