Karl Eduard Hammerschmidt also called Abdullah Bei and Carl (1800, Vienna - 30 August 1874, Anatolia) was an Austrian mineralogist, entomologist and physician.
Hammerschmidt studied the law, but could not become an advocate. Instead, already an editor of Landwirtschaftlichen Zeitung, an agricultural newspaper, and an entomologist, he became a student of medical writing.
After the Hungarian Revolution of 1848 he had to flee, joined the Hungarian army and fought under the Polish general Józef Bem. Wounded and with many suffering comrades he was pushed over the Turkish border. He became a teacher at the medical school in Constantinople, but after complaints from Austria was displaced. He then moved to Damascus where he worked for several years as a hospital physician, served as a physician in the Crimean War, was during the Vienna Exhibition of 1873 a Turkish commissioner.
After 1873, he became a teacher of mineralogy and Zoology at the medical school in Constantinople, for which he created a natural history museum. Hammerschmidt was a member of the Royal Entomological Society of London. As well as zoological and geological text books in the Turkish language he made valuable contributions to the geological and zoological knowledge of the Bosphorus areas. He was joint founder of the Turkish Red Crescent.
He died during the geological investigation of a new railway line in Anatolia.