Week 17
Week 17: April 23 – 29 (Archive)
April 23
- Max K. E. L. Planck, born 1858, introduced quantum theory (1900); researched thermodynamics; Nobel Prize in Physics (1918).
- Rohm & Haas Co. incorporated in 1917.
April 24
- Jean C. de Marignac, born 1817; in 1880, discovered gadolinium (Gd, 64).
April 25
- Wolfgang Pauli, born 1900, discovered exclusion principle; Noble Prize in Physics (1945).
- James D. Watson and Frances H. C. Crick published "Molecular Structure of Nucleic Acids: A Structure of Deoxyribose Nucleic Acid," in 1953.
April 26
- Michael Smith, born 1932, invented oligonucleotide-based, site-directed mutagenesis of DNA; Nobel Prize in Chemistry (1993).
April 27
- Antoine-Laurent Lavoisier reported that heating red calx (metal oxide) of mercury, HgO, in presence of powdered charcoal resulted in liberation of oxygen and reduction of mercury calx in 1775.
- Wallace Carothers, born 1896, developed nylon (1935).
- Philip H. Abelson, born 1913; in 1940, codiscovered neptunium (Np, 93).
- Albert Ghiorso et al. announced the discovery of element 105, produced by bombardment of californium-249 with nitrogen-15, in 1970.
April 28
- Franz K. Achard, born 1753, first to prepare a platinum crucible (1784); invented process for extraction of sugar from sugar beets; opened first beet sugar factory (1801).
- Barry Sharpless, born 1941, discovered and developed many catalytic oxidation proceses for stereoselective oxidation; Nobel Prize in Chemistry (2001).
April 29
- Atlantic Richfield Co. incorporated in 1870.
- Harold C. Urey , born 1893; in 1932, first to isolate heavy water (D2O); Nobel Prize in Chemistry (1934).
- Nashua incorporated as Nashua Card, Gummed & Coated Paper in 1904.