Theodore William Richards (January 31, 1868 – April 2, 1928) was the first American scientist to receive the Nobel Prize in Chemistry, earning the award “in recognition of his exact determinations of the atomic weights of a large number of the chemical elements.” He was born in German town, Philadelphia, Pennsylvania to William Trost Richards, a land- and seascape painter, and Anna née Matlack, a poet. Richards received most of his pre-college education from his mother. Beginning in 1878, the Richards family spent two years in Europe, largely in England, where Theodore Richards’ scientific interests grew stronger.
After the family’s return to the United States, he entered Haverford College, Pennsylvania in 1883 at the age of 14, earning a Bachelor of Science degree in 1885. He then enrolled at Harvard University and received a Bachelor of Arts degree in 1886, as further preparation for graduate studies. Richards continued on at Harvard, taking as his dissertation topic the determination of the atomic weight of oxygen relative to hydrogen. His doctoral advisor was Josiah Parsons Cooke.
Richards’ maintained interests in both art and music. Among his recreations were sketching, golf, and sailing. He died at Cambridge, Massachusetts, on April 2, 1928, at the age of 60. According to one of his descendants, Richards suffered from “chronic respiratory problems and a prolonged depression.”
About half of Richards’s scientific research concerned atomic weights, starting in 1886 with his graduate studies. On returning to Harvard in 1889, this was his first line of research, continuing up to his death. According to Forbes, by 1932 the atomic weights of 55 elementshad been studied by Richards and his students. Among the potential sources of error Richards uncovered in such determinations was the tendency of certain salts to occlude gases or foreign solutes on precipitation. As an example of the care Richards used in his work, Emsley reports that he carried out 15,000 recrystallizations of thulium bromate in order to obtain the pure element thulium for an atomic weight measurement.
Richards was the first to show, by chemical analysis, that an element could have different atomic weights. He was asked to analyze samples of naturally occurring lead and lead produced by radioactive decay. His measurements showed that the two samples had different atomic weights, supporting the concepts of isotopes.
Other scientific work of Theodore Richards included investigations of the compressibilities of atoms, heats of solution and neutralization, and the electrochemistry of amalgams. His investigation of electrochemical potentials at low temperatures was among the work that led, in the hands of others, to the Nernst heat theorem and the Third law of thermodynamics, although not without heated debate between Nernst and Richards. Richards also is credited with the invention of the adiabatic calorimeter as well as the nephelometer, which was devised for his work on the atomic weight of strontium.