Portal:History of science/Selected anniversaries/June 27

June 27: National HIV Testing Day in United States
 * 1717 - Birth of Louis Guillaume Lemonnier, French botanist (d. 1799)
 * 1740 - Birth of John Latham, Australian physician and naturalist (d. 1837)
 * 1787 - Birth of Thomas Say, American naturalist (d. 1834)
 * 1829 - Death of James Smithson, English mineralogist and philanthropist (b. 1765)
 * 1831 - Death of Sophie Germain, French mathematician (b. 1776)
 * 1839 - Death of Allan Cunningham, English botanist and explorer (b. 1791),
 * 1850 - Birth of Jørgen Pedersen Gram, Danish mathematician (d. 1919)
 * 1869 - Birth of Hans Spemann, German embryologist and Nobel Prize laureate (d. 1941)
 * 1898 - The first solo circumnavigation of the globe is completed by Joshua Slocum from Briar Island, Nova Scotia.
 * 1918 - Death of George Mary Searle, American astronomer (b. 1839)
 * 1931 - Birth of Martinus J. G. Veltman, Dutch physicist and Nobel Prize laureate
 * 1952 - Death of Max Dehn, German mathematician (b. 1878)
 * 1954 - The world's first nuclear power station opens in Obninsk, near Moscow.