Aix, a town of southern France, department of Bouches-du-Rhone, 15 m. N. of Marseilles; pop. in 1866, 28,152. It is the see of an archbishop, and possesses a museum and one of the best provincial libraries of France, containing 100,000 volumes. It was the Aquas Sextire of the Romans, so called on account of its thermal springs by Sextius Calvinus, who founded it after a victory achieved there over the Gauls, 123 B. C. Between Aix and Aries is the battle field on which Marius gained his great victory over the Teutons, 102 B. C. The counts of Provence made Aix their capital. The town is handsome, and adorned with a beautiful promenade. The cathedral, the clock tower in the market place, containing a curious clock, and the hotel de ville, are fine specimens of middle-age architecture. The mineral baths are but little frequented; they are impregnated with sulphur, and are said to soften and improve the skin.