Casanova did not reach this period, in writing his Memoirs, but an
account of this meeting is given by Da Ponte, who was present at it, in
his Memoirs. Costa had met with many misfortunes, as he told Casanova,
and had himself been defrauded. Casanova threatened to have him hanged,
but according to Da Ponte, was dissuaded from this by counter accusations
made by Costa.

Da Ponte's narration of the incident is brilliant and amusing, in spite
of our feeling that it is maliciously exaggerated: "Strolling one morning
in the Graben with Casanova, I suddenly saw him knit his brows, squawk,
grind his teeth, twist himself, raise his hands skyward, and, snatching
himself away from me, throw himself on a man whom I seemed to know,
shouting with a very loud voice: 'Murderer, I have caught thee.' A crowd
having gathered as a result of this strange act and yell, I approached
them with some disgust; nevertheless, I caught Casanova's hand and almost
by force I separated him from the fray. He then told me the story, with
desperate motions and gestures, and said that his antagonist was
Gioachino Costa, by whom he had been betrayed. This Gioachino Costa,
although he had been forced to become a servant by his vices and bad
practices, and was at that very time servant to a Viennese gentleman, was
more or less of a poet. He was, in fact, one of those who had honored me
with their satire, when the Emperor Joseph selected me as poet of his
theater. Costa entered a cafe, and while I continued to walk with
Casanova, wrote and send him by a messenger, the following verses:

"'Casanova, make no outcry;
You stole, indeed, as well as I;
You were the one who first taught me;
Your art I mastered thoroughly.
Silence your wisest course will be.'