[1] He graduating as an MD in 1795, with his thesis studying the work of Galvani that suggested the presence of nervous fluid with dynamical electricity.
[2] He was Professor of Chemistry at Trinity College, Dublin (1808–50), and Secretary to the Irish Board of Health (1820–32).
[1] Barker married Emma (née Conolly), the daughter of the vicar of Donard, County Wicklow in 1804.
[1] Barker edited the Dublin Pharmacopeia from 1826[2] and in collaboration with John Cheyne wrote An account of the rise, progress and decline of the fever lately epidemical in Ireland (2 vols., 1821).
[3][4] Barker's work with Cheyne highlighted the link between poverty and low hygiene standards in the spread of typhus in 1816–19.