Solothurn, French Soleure,  canton, northwestern Switzerland. It is bounded by the cantons of Bern to the west and south, Jura to the west, Aargau to the east, and Basel-Landschaft (demicanton) to the north. It is drained by the Aare River and its tributaries. Consisting of territories acquired by Solothurn (q.v.), its capital city, from which [...]