August Wilhelm von Hofmann (8 April 18185 May 1892) was a German chemist who made considerable contributions to organic chemistry. His research on aniline helped lay the basis of the aniline-dye industry, and his research on coal tar laid the groundwork for his student Charles Mansfield's practical methods for extracting benzene and toluene and converting them into nitro compounds and amines. Hofmann's discoveries include formaldehyde, hydrazobenzene, the isonitriles, and allyl alcohol. He prepared three ethylamines and tetraethylammonium compounds and established their structural relationship to ammonia. After studying under Justus von Liebig at the University of Giessen, Hofmann became the first director of the Royal College of Chemistry, now part of Imperial College London, in 1845. In 1865 he returned to Germany to accept a position at the University of Berlin as a teacher and researcher. After his return he co-founded the German Chemical Society (Deutsche Chemische Gesellschaft) (1867). In both London and Berlin, Hofmann recreated the style of laboratory instruction established by Liebig at Giessen, fostering a school of chemistry focused on experimental organic chemistry and its industrial applications. Hofmann received several significant awards in the field of chemistry, including the Royal Medal (1854), the Copley Medal (1875) and the Albert Medal (1881). He was elected as a member of the American Philosophical Society in 1862. He was ennobled on his seventieth birthday. His name is associated with the Hofmann voltameter, the Hofmann rearrangement, the Hofmann–Martius rearrangement, Hofmann elimination, and the Hofmann–Löffler reaction. Early life and education August Wilhelm Hofmann was born at Giessen, Grand Duchy of Hesse, on 8 April 1818. He was the son of Johann Philipp Hofmann, privy councillor and provincial architect to the court at Darmstadt. As a young man, he travelled widely with his father. August Wilhelm matriculated at the University of Giessen in 1836. He originally took up the study of law and philology at Giessen. He may have become interested in chemistry when his father enlarged Liebig's Giessen laboratories in 1839. August Wilhelm changed his studies to chemistry, and studied under Justus von Liebig. He obtained his PhD there in 1841. In 1843, after his father's death, he became one of Liebig's assistants. His association with Liebig eventually became personal as well as professional. Both his first wife, Helene Moldenhauer (m. 12 August 1846), and his third wife, Elise Moldenhauer (m. 19 May 1866), were nieces of Liebig's wife, Henriette Moldenhauer. Hofman reportedly