Th: Jefferson returns thanks to mr Derbigny for the copy of his Refutation of M. Duponceau which he has been so kind as to forward him. both that and the Examen of M. Thierry have thrown much new light on the subject, and further aid is still expected from M. Moreau de Visla, who is said to be engaged on the same subject. the papers are all referred by the House of Representatives to the Attorney General to report on to them, who undoubtedly will derive new aid from the very able opinions before mentioned. he salutes mr Derbigny with respect.