He did so, and finding that the stone had the virtue which Virgil ascribed to it, said to the sage one day:
“How was it that thou didst find out and understand the value of that gem?”
“I knew it, because I saw that there was in the stone a very small fly (moschettina—gnat), and I knew that flies are very quick and gay, and have great cleverness, as anyone can see if he tries to catch them, and they make love all the time.”
“Truly thou art a devil, oh Virgil,” replied the Emperor; “and for reward I hereby make thee Emperor or Pope over all the flies. There are, by the way, far too many of them, and a perfect plague—they spoil all the meat in the shops. I would that thou couldst banish all thy subjects from Rome.”
“I will do it,” answered Virgil.
Then, by his magic, he summoned the Great Fly—Il Moscone, the King of all the Flies—and said to him:
“Thy subjects are far too many, and a sore plague to all mankind. I desire that thou wilt drive them all out of Rome.”
“I will do it,” replied the Moscone, “if thou wilt make a fly of gold as large as a great frog, and put it in my honour in the Church of Saint Peter. After which, there will no more flies be seen in Rome.”
Then Virgil went to the Emperor and told him what Il Moscone had said, and the Emperor commanded that the fly should be made of many pounds of gold, and it was placed in the Church of Saint Peter, and so long as it remained there no fly was ever seen within the walls of Rome.
I have another version of what is partially the same story, but with a curious addition, which is of greater antiquity and most unconsciously really Virgilian, or the old tale of the bull’s hide.