At the beginning of the 20th century, the search for suitable narcotic drugs was one of medicine's most important objectives. As a possible anaesthetic, Avertin was synthesized in 1923 by the chemists Richard Willstatter (1872-1942) and Walther Duisberg (1892-1964). The pediatrician Albert Eckstein (1891-1950) and the pharmacist Fritz Eichholtz (1889-1967) carried out the first experiments. The surgeon Otto Butzengeiger (1885-1968) was the first to use Avertin for human narcotisation in a clinical study carried out on adults in 1926-1927. He developed a special intestinal catheter for rectal application. He reported on his experiments at the 51st Surgeons' Congress in 1927. Although he promoted a further trial of Avertin, Butzengeiger himself and the pharmacologist Walther Straub (1874-1944) recommended only a basic narcotic application. Avertin did not get general worldwide acceptance for use as. an anaesthetic because it was difficult to control and because of its side effects.