Fa\`a di Bruno's note on eponymous formula, trilingual version

Understand

About 160 years ago, the Italian mathematician Fa\`a di Bruno published two notes dealing about the now eponymous formula giving the derivative of any order of a composition of two functions.

• We reproduce here the two original notes, Fa\`a di Bruno (1855, 1857), written respectively in Italian and in French, and propose a translation in English.