text: *Edgar Fahs Smith Memorial Collection in the history of chemistry at the University of Pennsylvania, opened in 1931
  *Discovery of helium in natural gas by Hamilton Cady and David Ford McFarland at the University of Kansas in 1905
  *Isolation of organic free radicals by Moses Gomberg at the University of Michigan in 1900 
  *Discovery of new elements beyond Curium by researchers at the Lawrence Berkeley National Laboratory in Berkeley, California
  *Bowood House in Wiltshire, U.K., site of Joseph Priestley's discovery of oxygen in 1774
  *Nucleic acid and protein chemistry at Rockefeller University
  *Wallace Carothers' research on polymers at DuPont between 1928 and 1937