In 1863 he returned to the University of Edinburgh to accept the position of an extra-academical lecturer in chemistry. In 1865 he became a fellow of the Royal College of Physicians, and was appointed Professor of Chemistry at Edinburgh in 1869, holding the Chair until his retirement in 1908. In the application for this position he was supported by such famous chemists as Baeyer, Beilstein, Bunsen, Butlerov, Erlenmeyer, Hofmann, Kolbe, Volhard and Wöhler. The Crum Brown Chair of Chemistry at the University of Edinburgh was established in 1967 in his honour. He was elected a Fellow of the Royal Society of Edinburgh in 1863, was awarded their Keith Medal for 1873-75, and served as their Vice President from 1905 to 1911. His address at the time of joining the Society was given as 8 Belgrave Crescent in the west end of Edinburgh.
Each year, the Hope Scholarship was awarded to the four students at the University of Edinburgh who achieved the highest marks in the first-term examinations in Chemistry. The Hope Scholars were entitled to free use of the laboratory facilities during the following term. In 1870, Edith Pechey, one of the Edinburgh Seven, came third in the class, beaten by two male students sitting the exam for the second time, so under the terms of the Hope Scholarship, she had first claim on it. Fearing that awarding the prize to a woman would be both an affront to many of his esteemed colleagues in the Medical Faculty and a provocation to the male students, Crum Brown chose to award the Hope Scholarship to men whose names appeared lower on the list. This had important consequences. It made national headlines in The Times and drew attention to the difficulties being encountered by a small group of women studying medicine at Edinburgh University.
" has done her sex a service, not only by vindicating their intellectual ability in an open competition with men, but still more by the temper and courtesy with which she meets her disappointment"
Research
Crum Brown's pioneering work concerned the development of a system of representing chemical compounds in diagrammatic form. In 1864 he began to draw pictures of molecules, in which he enclosed the symbols for atoms in circles, and used dashed lines to connect the atomic symbols together in a way that satisfied each atom's valence. The results of his influential work were published in 1864 and reprinted in 1865. Although Crum Brown apparently never contemplated the practice of medicine, his training as a medical student gave him an interest in physiology and pharmacology which led him to collaborate during 1867–8 with T. R. Fraser, a distinguished medical graduate a few years younger than himself, in a pioneering investigation of fundamental importance on the connection between chemical constitution and physiological action. Their method "consists in performing upon a substance a chemical operation which shall introduce a known change into its constitution, and then examining and comparing the physiological action of the substance before and after the change." The change considered was the addition of ethyl iodide to various alkaloids and comparison of the iodides thus obtained with the hydrochlorides of the original alkaloids. Striking regularities were observed, amongst others "that when a nitrile base possesses a strychnialike action, the salts of the corresponding ammonium bases have an action identical with curare ." He discovered the carbon double bond of ethylene, which was to have important implications for the modern plastics industry. He also made significant contributions to pharmacology, and worked with physiology, phonetics, mathematics and crystallography. In 1912, he introduced the name of kerogen to cover the insolubleorganic matter in oil shale.
Personal life
Although physically not very robust, Crum Brown spent much of his holiday time in tramping in the highlands and on the continent, and was rarely ill. He married early in his professorial life, to Jane Bailie Porter, the sister of William Archer Porter, a lawyer and educationist who served as the Principal of Government Arts College, Kumbakonam and tutor and secretary to the Maharaja of Mysore, James Porter and Margaret Archer Porter, who married Peter Tait. He remained intellectually active until his death in Edinburgh in 1922.
In 2015 the City of Edinburgh Council agreed a request by the University of Edinburgh to name a street within the King's Buildings complex after Crum Brown.
