There was once a doctor whose name was Giordano, and he had a disciple. A son of the king fell ill. Master Giordano went to him, and saw that the illness could be cured. The disciple, in order to injure his master's reputation, said to the father: I see that he will certainly die.

And so disputing with his master, he made the sick youth open his mouth, and with his little finger inserted poison therein, making a great show to understand the nature of the illness from the state of the tongue.

The son died.

The master went away, and lost his reputation, while the disciple increased his.

Then the master swore that in future he would only doctor asses, and so he made physic for beasts and the lower animals.¹

¹ The source of the tale is Liber Ipocratis de infirmitibus equorum.