 This is why Frederick Walker Mott and William Dobinson Halliburton noted in 1899 that choline injections decreased the blood pressure of animals.Acetylcholine was first noted to be biologically active in 1906, when Reid Hunt (1870–1948) and René de M. Taveau found that it decreased blood pressure in exceptionally tiny doses.In 1914, Arthur J. Ewins was the first to extract acetylcholine from nature.