Alexander Fleming, M.D. (1824 Edinburgh – 21 August 1875) was a Scottish physician, educator, researcher and author whose research led to the development of Fleming's tincture. Born in Scotland, Fleming studied medicine at the University of Edinburgh, where he graduated in 1844. His chief work was his college essay on the 'Physiological and Medicinal Properties of Aconitum Napellus,' Lond. 1845, which led to the introduction of a tincture of aconite of uniform strength known as Fleming's tincture. Fleming retired due to ill-health in 1873. He died at Brixton, London, on 21 August 1875.