An excerpt from the Introduction:
"...Mezofanti liked to quip that he knew 'fifty languages and Bolognese.' During his lifetime, he put enough of those on display -- among them Arabic and Hebrew (biblical and
Rabbinic), Chaldean, Coptic, Persian, Turkish, Albanian, Maltese, certainly Latin and Bolognese, but also Spanish, Portuguese, French, German, Dutch, and English, as well as
Polish, Hungarian, Chinese, Syrian, Amharic, Hindustani, Gujarati, Basque, and Romanian -- that he frequently appeared in rapturous accounts of visitors to Bologna and Rome.
Some compared him to Mithradates, the ancient Persian king who could speak the language of each of the twenty-two territories he governed. The poet Lord Byron, who once lost
a multilingual cursing contest with Mezzofanti, called him 'a monster of languages, the Briareus of parts of speech, a walking polyglott, and more, -- who ought to have
existed at the time of the Tower of Babel, as universal interpreter.' ...
"On one occasion, Pope Gregory XVI (1765-1846), a friend of Mezzofanti, arranged for dozens of international students to surprise him. When the signal was given, the students
knelt before Mezzofanti and then rose quickly, talking to him 'each in his own tongue, with such an abundance of words and such a volubility of tone, that, in the jargon of
dialects, it was almost impossible to hear, much less to understand them.' Mezzofanti didn't flinch but 'took them up singly, and replied to each in his own language.' The
pope declared the cardinal to be victorious. Mezzofanti could not be bested."
 - https://en.wikipedia.org/wiki/Mezzofanti
 - https://www.amazon.com/Babel-No-More-Extraordinary-Language/...