Theodore William Richards, a professor of chemistry at Harvard University, was the first American chemist to receive a Nobel Prize. The prize was awarded to Richards in 1914 in chemistry for his accurate determination of the atomic weights of twenty-five chemical elements. He was renowned for his unsurpassed laboratory skill in chemical analysis. His work provided essential fundamental data for practical and theoretical chemists and physicists, and his graduate program at Harvard produced many eminent educators and research scientists.
Richards, the fifth of six children, was born on January 31, 1868, in Germantown, Pennsylvania, to William Trist Richards, a painter of seascapes, and Anna Matlack Richards, a writer and poet. Until he was fourteen, Richards received all his education from his mother, who had little regard for the public schools of Germantown. His interest in chemical experiments began when he was ten; when he was thirteen, he attended lectures in chemistry at the University of Pennsylvania. At the age of fourteen, Richards enrolled in Haverford College as a sophomore and graduated at the head of his class with a specialty in chemistry in 1885. Upon graduation, Richards enrolled at Harvard to study chemistry with Josiah Cooke, a professor whom he had met on summer vacation when he was six years old. Richards received his second baccalaureate, with summa cum laude distinction, at Harvard in 1886, and remained to study for the Ph.D. under Cooke's supervision. He received his doctorate in 1888, when he was twenty.
Richards's dissertation research marked the beginning of his study of atomic weights, which formed the major field of investigation in his long career. Richards published over 150 papers on atomic weights, beginning with his doctoral research on the atomic weight of hydrogen. At the time, chemists theorized that all elements were made from hydrogen and that there should be an integral ratio between the atomic weight of hydrogen and other elements. Although the theory called for the ratio of oxygen to hydrogen in water to be exactly 16, Richards's careful laboratory work, which involved difficult manipulations of gases, showed the ratio was actually 15.869 and strongly suggested that the theory was erroneous.
In the 1888-89 academic year, Richards received a fellowship and visited analytical laboratories in Europe. He returned to Harvard to become an assistant in the analytical chemistry course. He was promoted to instructor in 1891, assistant professor in 1894, and full professor in 1901 (after rejecting an offer from the University of Göttingen). He taught analytical chemistry until 1902 and physical chemistry from 1895, after the death of Josiah Cooke. He was chairman of the chemistry department from 1903 to 1911 and director of the Wolcott Gibbs Laboratory from 1912 until his death in 1928.
The measurement of atomic weights coincides with the beginning of modern chemistry, with Antoine-Laurent Lavoisier's conception of chemical elements and with John Dalton's atomic theory, which established that atoms are the building blocks of matter. The chemists of the nineteenth century had determined the atomic weights of all the known elements, and Dmitry Mendeleyev based his periodic table of the elements on these values. However, all values of the atomic weights at the time were relative values, where ratios of atomic weights were actually determined in chemical compounds, and an error in a crucial ratio meant that the atomic weights of several elements would be inaccurate. For example, if the silver to chlorine ratio in silver chloride was inaccurate, then the atomic weight of sodium from sodium chloride or potassium from potassium chloride would consequently be erroneous.
Richards found that the long-accepted atomic weight values of the French chemist Jean-Servais Stas were incorrect because of several experimental errors which had been previously overlooked. The crucial part of the analysis of atomic weight involves the complete collection of a pure precipitate; Richards showed that Stas's compounds were impure and that Stas had not accounted for all of the chemical product. Richards and his students were able to redetermine accurately the atomic weights of twenty-five elements, and other chemists who had studied with Richards added thirty more elements. In his studies, Richards showed that the geographical origins of the elements does not affect their atomic weights (he determined that terrestrial and meteoric iron have identical values). Richards's determination of physical constants, which were used by all chemists, won the admiration of the chemistry community and led to his Nobel Prize.
Richards's work was also important to the dramatic new discoveries of early twentieth-century scientists in radioactivity and the structure of the atomic nucleus. Richards determined that the atomic weight of ordinary lead was different from that of lead which came from the radioactive decay of uranium. This critical evidence corroborated theories of radioactivity, and because of Richards's reputation for accuracy, the experimental result was readily accepted by many scientists.
In addition to his work on atomic weights, Richards also directed research in physical chemistry. Before he began to teach physical chemistry at Harvard, he was sent to Germany to study with two leaders in the field, Nobel Prize winners Friedrich Wilhelm Ostwald and Walther Nernst. Richards invented an improved calorimeter for measuring heat in chemical reactions and published sixty papers in thermochemistry. He also contributed to the field of electrochemistry. His sixty graduate students became distinguished professors at other universities and continued the research studies they began at Harvard. Richards's influence on American chemical research in analytical and physical chemistry was exceptional.
In addition to the Nobel Prize, Richards won scientific awards from many nations. He also served as president of the American Chemical Society (1914), the American Association for the Advancement of Science (1917), and the American Academy of Arts and Sciences (1920-1921). Outside of his scientific interests, he enjoyed sketching, sailing, and golf.
In 1896, Richards married Miriam Stuart Thayer, daughter of Professor Joseph H. Thayer of the Harvard divinity school. Their son William studied chemistry with his father at Harvard and went on to teach at Princeton. Another son, Greenough, became an architect, and their daughter, Grace, married James B. Conant, one of Richards's graduate students. Conant became professor of organic chemistry and president of Harvard University. Richards died in Cambridge, Massachusetts, on April 2, 1928.
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