Element timelines By 38207 Jan 1, 1807 Sodium Humphry Davy Jan 1, 1808 Boron Discovered by Louis Jacques Thénard, Joseph Louis Gay-Lussac Jan 1, 1808 Magnesium Dicovered by Joseph Black Aug 1, 1823 Silicon Discovered by Jöns Jacob Berzelius Jan 1, 1886 Fluorine Discovered by Henri Moissan