Liebig, Justus, Baron von (yo͝os`to͝os bärôn` fən lē`bĭkh), 1803–73, German chemist. As professor at Giessen (1824–52), he was among the first to establish a chemical teaching laboratory; there some of the leading chemists of the 19th cent. were trained. He was professor at Munich from 1852 to 1873. Liebig improved methods of organic analysis and investigated organic compounds such as uric acid. He discovered chloral and was one of the discoverers of chloroform. He made valuable contributions to agricultural chemistry. Liebig refuted the prevalent theory that plants derive their nourishment from humus and emphasized the importance to plants of the nitrogen and carbon dioxide of the air and of the mineral constituents of the soil; subsequently he did important work in the development of artificial fertilizers. His works include Organic Chemistry in Its Applications to Agriculture and Physiology (1840, tr. 1840).