Alexander Crum Brown FRSE FRS (26 March 1838 – 28 October 1922) was a Scottish organic chemist.

In his application for this position he was supported by famous chemists such as Baeyer, Beilstein, Bunsen, Butlerov, Erlenmeyer, Hofmann, Kolbe, Volhard and Wöhler.

[12] Each year, the Hope Scholarship was awarded to the four students at the University of Edinburgh who achieved the highest marks (at first sitting) in the first-term examinations in Chemistry.

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.

It made national headlines in The Times and drew attention to the difficulties being encountered by a small group of women studying medicine at the University of Edinburgh.

"[Miss Pechey] 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"[13]Crum Brown's pioneering work concerned the development of a system of representing chemical compounds in diagrammatic form.

[15] Although Crum Brown apparently never contemplated the practice of medicine, his training as a medical student gave him an interest in physiology and pharmacology.

This led him to collaborate during 1867–8 with T. R. Fraser, a distinguished medical graduate, in a pioneering investigation of fundamental importance into the connection between chemical constitution and physiological action.

"[6] He discovered the carbon double bond of ethylene, which was to have important implications for the modern plastics industry.

[6] Crum Brown died 28 October 1922, aged 84, and is buried on the obscured southern terrace of Dean Cemetery.

[citation needed] William Brassey Hole's sketch of Crum Brown in a laboratory in 1884, is held by the Scottish National Portrait Gallery.