“…and Sansum,12 Kleiner,19 Nonnenbruch and Szyszka 20 and Bang.21 Blumenthal,13 in 1904, attempted to determine glucose tolerance by the intravenous method, but he made no blood sugar estimations, depending on the production of glycosuria and leaving out of consideration the permeability of the kidneys. In 1913, Tannhauser and Pfitzer 14 made the first clinical attempt to determine the hyperglycemia caused in man by the injection of small amounts of glucose solution into a vein.…”