Complex sentence: In 1818 his most known work, "Dictionnaire Infernal", was published, and in 1863 there were added some images that made famous the edition; this is a book on demonology, which contains some imaginative drawings concerning the appearance of certain demons.
Split into simpler sentences: In 1818 his best known work, "Dictionnaire Infernal", was published. In 1863 were added some images that made it famous: imaginative drawings concerning the appearance of certain demons.