In addition to these he wrote Fragments inédits de Georges Chastellain and Lettres, mémoires et autres documents relatifs à la guerre du bien public en 1465.

[2] These works did not wholly occupy his time: in 1847, he inaugurated a course of archaeological lectures at the École des Chartes, and in 1849, was appointed professor of diplomatics at the same college.

At one point, he seems to have taken a false step; with a warmth and pertinacity worthy of a better cause, he maintained the identity of Caesar's Alesia with Alaise, and he died without becoming a convert to the opinion, now almost universally accepted, that Alise Sainte-Reine is the place where Vercingetorix capitulated.

But even this error benefited science; some well-directed excavations at Alaise brought many Roman remains to light, which were subsequently sent to enrich the museum at Besançon.

He died suddenly in Paris on April 8, 1882, a short time after correcting the proofs of Supplément aux témoignages contemporains de Jeanne d'Arc, published in the Revue Historique.

[2] After his death, it was decided to bring out his hitherto unpublished papers; among these are some important fragments of his archaeological lectures, but his Histoire de la laine, with which he was occupied for many years, is missing.