“…52 Ladenburg is first from the left in the second row; to his left are the Danish chemist Sophus Mads Jørgensen (1837-1914), the Finnish chemist and historian of chemistry Edvard Hjelt (1855-1921), the German chemist Hans Heinrich Landolt (1831-1910), the German chemist Clemens Alexander Winkler (1838-1904), who discovered germanium in 1886, and T. E. Thorpe. Seated from the left to right in the front row are the Dutch chemist Jacobus Henricus van't Hoff (1852-1911), who won the Nobel Prize in Chemistry in 1901, the Russian -German chemist Friedrich Konrad Beilstein (1838-1906), 53 the Scottish chemist William Ramsay (1852-1916), who found neon, argon, krypton, and xenon in air and was awarded the Nobel Prize in Chemistry in 1904, the Russian chemist D. I. Mendeleev, who discovered the Periodic Law in 1871, the German chemist Adolf von Baeyer (1835-1917), who received the Nobel Prize in Chemistry in 1905, and the Italian chemist Alfonso Cossa (1833-1902).…”