Heinrich Landolt (5 December 1831 – 15 March 1910) was a Swiss chemist who discovered iodine clock reaction. He is also one of the founders of Landolt–Börnstein
lenses). Landolt grew up in the Zürich district Enge. He was the eldest son of the lawyer, politician and later Zürich's mayor EmilLandolt and the great-grandson
Friedrich Konrad Beilstein, 1838–1906; Emil Erlenmeyer, 1825–1909; Rudolph Fittig, 1835–1910; Hans Heinrich Landolt, 1831–1910; Nikolai Alexandrovitsch Menschutkin