Editing Emil Erlenmeyer (section)

==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.<ref>See biography by Conrad, in Further Reading.</ref> 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 a [[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 [[Friedrich August Kekulé von Stradonitz|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 ===
[[Image:Erlenmeyer flask.jpg|thumb|Erlenmeyer flask|232x232px]]In 1863 he became associate professor at the University of Heidelberg.  In 1868 he was hired as a full professor in [[Munich]] to take charge of the laboratories of the new [[Technical University of Munich|Munich Polytechnic School]], a post which he held until he retired from teaching in 1883.

His work mostly focused on theoretical chemistry, where he suggested the structural formula for [[naphthalene]]. The Erlenmeyer rule states that all [[Alcohol (chemistry)|alcohol]]s in which the hydroxyl group is attached directly to a double-bonded carbon atom become [[aldehyde]]s or [[ketone]]s (cf. [[Enol|keto-enol tautomerism]]).

Erlenmeyer's practical investigations were concerned mostly with [[aliphatic compound]]s. In 1859 he synthesised [[aminohexoic acid]] and proceeded to study the general behavior of [[albumin]]oids on [[hydrolysis]]. He worked out methods to determine the relative amounts of [[leucine]] and [[tyrosine]], which are produced during the degradation of several substances of this class, and was the first (1860) to understand the nature of [[glycide]] and to suggest that this substance is related to [[glycerol]] in the same way as is [[metaphosphoric acid]] to [[orthophosphoric acid]]. In the following year he studied the action of [[hydroiodic acid]] on [[glycerol]], and showed that the product was [[isopropyl iodide|isopropyl]]- and not [[propyl iodide]]. His investigations of the higher alcohols produced during fermentation yielded the important proof that these alcohols do not belong to the normal series.<ref name=r1/>

His other work included the isolation of [[glycolic acid]] from unripe grapes (1864), synthesis of [[sodium oxalate]] by heating [[sodium formate]] (1868), hydrolysis of ether to alcohol (1858), synthesis of phenyl-lactic acid (1880), preparation of [[pyruvic acid]] by the distillation of [[tartaric acid]] (1881) and the formation of [[carbostyril]] from [[quinoline]] (1885).

His investigations in the aromatic series include isomerism of the [[cinnamic acid]]s and the synthesis of [[tyrosine]] from [[phenylalanine]] (1882). In 1875, by nitrating [[benzoic acid]], Erlenmeyer disproved the prevalent opinion that more than three [[nitrobenzoic acid]]s exist.

In 1860 he published a description of the [[Erlenmeyer flask|conical flask]] that bears his name.<ref name=r1/>
<ref>Emil Erlenmeyer, "Zur chemischen und pharmazeutischen Technik," ''Zeitschrift für Chemie und Pharmacie'', vol. 3 (January 1860), 21-22.  He wrote that he first displayed the new flask at a pharmaceutical conference in Heidelberg in 1857, and that he had arranged for its commercial production and sale by local glassware manufacturers.</ref>