Photograph captioned: Ferdinand Graft Brickwedde (1903-1989), with his wife, physicist Marion Langhorne Howard Brickwedde (1909-1997). Between them is the apparatus for making heavy water. Marion Brickwedde earned a B.S. in chemistry (1929) and M.S. in physics (1930) from University of Georgia. During her career, she taught physics at George Washington University and Pennsylvania State University, and was on the research staffs of the U.S. National Bureau of Standards and Los Alamos National Laboratory. Ferdinand Graft Brickwedde was a physicist at the National Bureau of Standards (now the National Institute of Standards and Technology), in 1931 produced the first sample of hydrogen in which the spectrum of its heavy isotope, deuterium, could be observed. This was a critical step in the discovery of deuterium, for which Brickwedde's collaborator, Harold Urey, was awarded the Nobel Prize in Chemistry in 1934.