William Ramsay

1852-1916

British Chemist

The most eminent British chemist of the late nineteenth century, William Ramsay won the 1904 Nobel Prize for his discovery of the socalled "noble" gases. A brilliant experimentalist rather than a theorist, and one who did his best work in collaboration with others, his research helped to establish the new discipline of physical chemistry in Britain. A champion of educational reform, an accomplished linguist, poet, and athlete who traveled widely, and deeply religious, his generous nature, humility, and lively sense of humor made him a beloved figure.

Of Scottish descent, Ramsay was the only child of devout Calvinists, and descended from three generations of workers in the dyeing industry on his father's side. In 1869 he first began chemical studies at university in Glasgow, going to Tübingen in Germany in 1870 to study organic chemistry and obtaining his doctorate there in 1872. He then returned to Glasgow and served six years as an assistant at a technical college. In 1880 Ramsay advanced to a professorship at University College, Bristol, a move that coincided with a shift in his research interests from organic to physical chemistry. In 1881 he became principal of the College and wed Margaret Buchanan, and their happy union produced a daughter and a son. Between 1882 and 1887 he gained notice through several papers with Sydney Young, both on the thermal properties of solids and on the relation between rates of evaporation and molecular dissociation for substances at various pressures.

In 1887 Ramsay succeeded Alexander Williamson, the dean of British chemists, at University College, London, where he remained until retiring in 1912. His researches there initially focused on the behavior of nitrogen oxide compounds. Realizing that the current "hydrate theory" of solutions, which assumed that a solute and solvent form a weak chemical combination, could not explain the activity of electrolytes as freely moving charged particles, he became an advocate of the new "ionic" solution theory.

In September 1892 and April 1894, the renowned physicist Lord Rayleigh (John William Strutt; 1842-1919) published notices that two different methods of preparing elemental nitrogen, one from atmospheric air and the other from ammonia, consistently yielded products with very slightly differing densities. Ramsay, recalling Henry Cavendish's (1731-1810) famous 1785 experiment that isolated nitrogen from atmospheric air but left an unexplained minute gaseous residue, suspected that a previously unknown element awaited detection.

Between April and August 1894 Ramsay repeatedly passed quantities of atmospherically derived nitrogen over heated magnesium, which reacted to produce magnesium nitride. He thereby succeeded in isolating an unreacted gaseous fraction, which spectral analysis proved to be a new element, which he named "argon" (Greek for "inactive one"). Ramsay and Rayleigh's joint announcement of this discovery to the Royal Society of London created a sensation, since the new element showed no chemical activity and did not fit into the existing pattern of the recently established periodic table.

In March 1895 Ramsay read a report of the emission of an unknown gas from clèveite, a uranium-based mineral. He immediately bought the available supply of it in London, collected the gas by treating the mineral with sulfuric acid, and submitted it to spectral analysis. The result matched that of helium (from the Greek for "sun"), an element previously detected in the solar spectra but not known to exist on Earth. Between 1895 and 1898, with his assistant and later biographer Morris Travers, Ramsay painstakingly collected 15 liters of liquefied argon gas from atmospheric nitrogen. They repeatedly subjected this to fractional distillation, searching for minute traces of further elements. The resulting fractions were again subjected to spectral analysis, and between June and September 1898 yielded three new elemental gases: krypton ("hidden one"), neon ("new one"), and xenon ("strange one").

In later years until his death from cancer Ramsay, assisted by Frederick Soddy (1877-1956), investigated problems involving radioactive decay and elemental transmutation. These studies proved inconclusive, as they preceded necessary developments in atomic theory. However, a gaseous "emanation" from radium that Ramsay called "niton"—the molecular weight of which he determined from a minute sample in a remarkable experiment—was later proved to be yet another gas element, radon.

JAMES A. ALTENA