Richard August Carl Emil Erlenmeyer (28 June 182522 January 1909), known simply as Emil Erlenmeyer, was a German chemist known for contributing to the early development of the theory of structure, formulating the Erlenmeyer rule, and designing the Erlenmeyer flask, a type of specialized flask, ubiquitous in chemistry laboratories, which is named after him. Biography Early life and education Erlenmeyer was born in Wehen, Duchy of Nassau (today Taunusstein, Hesse, near Wiesbaden), in 1825, the son of a Protestant minister. He enrolled in the University of Giessen to study medicine, but after attending lectures of Justus von Liebig changed to chemistry. In the summer of 1846 he went to Heidelberg for one year, and studied physics, botany and mineralogy, returning to Giessen in 1847. After serving as assistant to H. Will and then to Carl Remigius Fresenius, Erlenmeyer decided to devote himself to pharmaceutical chemistry. For this purpose he studied in Nassau, where he passed the state pharmaceutical examination, and shortly afterwards acquired an apothecary's business, first at Katzenelnbogen and then in Wiesbaden. He became dissatisfied with pharmacy and returned to chemistry, finishing his doctorate at Giessen in 1850. In 1855 he moved to Heidelberg to work on the chemistry of fertilizers in the laboratory of Robert Bunsen. He wished to teach, but Bunsen's associates were not allowed to take private students. Therefore, with his wife's help, he converted a shed into a private laboratory. In 1857 he became privatdocent and his habilitation thesis "On the manufacture of the artificial manure known as superphosphate" contained a description of several crystalline substances which greatly interested Robert Bunsen. It was while at Heidelberg that Erlenmeyer was brought under the influence of August Kekulé, whose theoretical views he was one of the first to adopt. He was the first to suggest, in 1862, that double and triple bonds could form between carbon atoms, and he made other important contributions to the development of theories of molecular structure. Academic career In 1863 he became associate professor at the University of Heidelberg. In 1868 he was hired as full professor in Munich to take charge of the laboratories of the new Munich Polytechnic School, a post which he held until his retirement from teaching in 1883. His work mostly focused on theoretical chemistry, where he suggested the formula for naphthalene. The Erlenmeyer rule states that all alcohols in which the hydroxyl group is attached directly