page_title: Henry Edward Armstrong
section_title: Life and work
hierarchical_section_title: Henry Edward Armstrong / Life and work
caption_attribution_description: Deutsch: Henry Edward Armstrongs Vorschlag für die Benzol-Strukturformel im Original, entnommen aus: English: Henry Edward Armstrong's proposal for the benzene structure in its original, taken from: Henry Edward Armstrong (1887). "An Explanation of the Laws which govern Substitution in the case of Benzenoid Compounds". J. Chem. Soc., Trans. 51: 258–268. DOI:10.1039/CT8875100258. "I venture to think that a symbol free from all objections may be based on the assumption that of the twenty-four affinities of the six carbon-atoms twelve are engaged in the formation of the six-carbon ring and six in retaining the six hydrogen-atoms, in the manner ordinarily supposed; while the remaining six react upon each other, — acting towards a centre as it were, so that the ‘affinity’ may be said to be uniformly and symmetrically distributed. I would, in fact, make use of the following symbol: —"
context_page_description: Henry Edward Armstrong FRS FRSE was a British chemist. Although Armstrong was active in many areas of scientific research, such as the chemistry of naphthalene derivatives, he is remembered today largely for his ideas and work on the teaching of science. Armstrong's acid is named for him.
context_section_description: Armstrong was born the son of Richard Armstrong, a commission agent and importer, and Mary Ann Biddle. He lived most of his life in Lewisham, a suburb of London.
  After finishing school in 1864 at age 16, he spent a winter in Gibraltar, with a relative, for health reasons.  In the spring of 1865, Armstrong returned to England and entered the Royal College of Chemistry in London, now the department of chemistry at Imperial College. Chemical training in those days was not lengthy, and at the age of 18 he was selected by Edward Frankland to assist in devising methods of determining organic impurities in sewage.
  Armstrong pursued further studies under Hermann Kolbe at Leipzig, earning a Ph.D. in 1869 for work on "acids of sulfur." He returned to London and worked under Augustus Matthiessen in the medical school of St Bartholomew's Hospital, in charge of chemistry classes for students taking the London degree. A permanent appointment in 1879 at City and Guilds of London Institute, now also a part of Imperial College, followed. At age 36, Armstrong became Professor of Chemistry at yet another Imperial College precursor, the Central Institution in 1884. It was here that he established a three-year diploma course in chemical engineering, "seeing the need for a more scientific attitude of mind among British industrialists"
  He had already started on the systematic synthesis, degradation, and structural constitution of many naphthalene derivatives in 1881, building on earlier work on benzene derivatives and Erlenmeyer’s proposal for the structure of naphthalene. W. P. Wynne was his most important collaborator; their 263 naphthalene samples, accrued over several decades, are now preserved at Imperial College as the Armstrong-Wynne Collection.  This research on naphthalene gave much impetus to the synthetic dye industry.
  Armstrong's later researches dealt with terpenes, particularly camphor, with water purification, helping to eradicate typhoid fever, and with crystallography.
  In 1887, Armstrong became interested in classifying substituents of benzene in terms of their meta- and ortho-para directing influences. It was in a footnote to an article on that theme in 1890 that his centric formula for benzene first appeared. His six affinities acting within a cycle predated both the discovery of the electron and modern theories of aromaticity.  Armstrong recognised that affinities have direction and are not merely point particles, and so he might be said to have anticipated parts of the wave mechanical theories of the 1920s.
  He died at his home in Granville Park, Lewisham.
caption: Armstrong's centric structure for benzene
exif: {}