SOLOTHURN, a city of Switzerland, the capital of the canton of that name. It stands at the foot of the Jura mountains, on both sides of the river Aar. It is surrounded with walls and defended by bastions, is well, but irregularly built, and contains 560 houses, with 4470 inhabitants. It has a college with five professors and a good public library. Solothurn contains several manufactories for making and printing cotton, and some other goods. Lat. 47. 12. Long. 7. 26. E.