to a double-bonded carbon atom become aldehydes or ketones. Erlenmeyer's practical investigations were concerned mostly with aliphatic compounds. In 1859 he synthesised aminohexoic acid and proceeded to study the general behavior of albuminoids 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- 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. 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 acids and the synthesis of tyrosine from phenylalanine (1882). In 1875, by nitrating benzoic acid, Erlenmeyer disproved the prevalent opinion that more than three nitrobenzoic acids exist. In 1860 he published a description of the conical flask that bears his name. References Further reading Andrea Sella's Classic Kit 1825 births 1909 deaths 19th-century German chemists 20th-century German chemists University of Giessen alumni Heidelberg University alumni Academic staff of the Technical University of Munich