19th c. French illustration depicting hallucinatory dreams created by inhaling or drinking ether (diethyl ether). Its intoxicating effect had been known since 1540, and it was used medicinally from 1794. During the 19th century it was widely used as a recreational drug - especially at ether frolics parties. It also was used a substitute for alcohol. In 1844 it superseded nitrous oxide (laughing gas) as a dental anaesthetic before being replaced by chloroform from 1847.