Young Masson was educated at the college of Sainte Barbe, and at the lycée Louis-le-Grand, and then travelled in Germany and in England.
These were notes, extracts from historical, philosophical and literary books, and personal reflections in which one can watch the growth of the ideas later carried out by the emperor with modifications necessitated by the force of circumstances and his own genius.
But this was only one in a remarkable series: These works abound in details and amusing anecdotes, which throw much light on the events and men of the time, laying stress on the personal, romantic and dramatic aspects of history.
A bibliography of his works, including anonymous ones and those under an assumed name, has been published by Georges Vicaire (Manuel de l'amateur des livres du XIX siècle, tome v., 1904).
His personal library, his papers, his collection of paintings and objects about Napoléon are conserved now in the Fondation Dosne-Thiers, 27 place Saint-Georges, 75009 Paris (France).