He continued to work for the preservation of monuments, attending meetings of the Commission and advising Boeswillwald, who had replaced him as Inspector of Monuments in 1860. On his urging the Commission acted to protect the medieval village of Cordes-sur-Ciel, the Château de Villebon, and the romanesque churches of Saint-Émilion. He also continued to develop his passion for Russian literature, with the help of his friend Turgenev and other Russian émigrés in Paris. He began writing a series of twelve articles on the life of Peter the Great, based on a work in Russian by Nikolai Ustrialov, which appeared in the "Journal des Savants" between June 1864 and February 1868. He wrote to a friend that "Peter the Great was an abominable man surrounded by abominable villains. That is amusing enough for me". In 1869 he wrote to his friend Albert Stapfer that "Russian is the most beautiful language in Europe, not excepting Greek. It is richer than German, and has a marvelous clarity... It has a great poet and another almost as grand, both killed in duels when they were young, and a great novelist, my friend Turgenev".