Giessen, a town of Germany, capital of the province of Upper Hesse, in the grand duchy of Hesse-Darmstadt, situated at the confluence of the Wieseck with the Lahn, 30 m. N. of Frankfort; pop. in 1871, 12,245. It was originally fortified, but its ramparts have been levelled and converted into promenades. ' The town is well though irregularly built, and contains an old castle, a hospital, arsenal, and two churches. The university, which was founded in 1607, has 58 teachers and about 400 students, a library of 40,000 volumes, an observatory, botanical garden, and museum. Its school of organic chemistry under Liebig has been especially distinguished. Besides the university Giessen has a gymnasium and several other superior schools. Its manufactures consist of hosiery, hats, soap, candles, red and white leather, jewelry, weapons, liqueurs, vinegar, and tobacco. It has also breweries and oil mills, and a considerable trade in cattle.