AIX, a small but ancient town in the duchy of Savoy, with the title of a marquisate. It is seated on the lake Bourget, at the foot of a mountain, between Chamberry, Annecy, and Rumilly. There is here a triumphal arch of the ancient Romans, but it is almost entirely ruined. The mineral waters bring a great number of strangers to this place. The place was originally called Aqua Gratiana, from the hot baths built there by the emperor Gratian. E. Long. 5. 48. N. Lat. 45. 40.