Ramsay, Sir William
A student of the German analytical chemist Robert Bunsen at the University of Heidelberg (1871), Ramsay became professor of chemistry at the University of Bristol, England (1880-87), and at the University of London (1887-1913). Among his early studies was the physiological action of alkaloids (complex chemical compounds derived from plants); he established their relationship to pyridine, a nitrogen-containing organic compound closely resembling benzene in chemical structure. With John Shields, he verified Roland Eötvös' law for the constancy of the rate of change of molecular surface energy with temperature.
When in 1892 the British physicist Lord Rayleigh asked chemists to explain the difference between the atomic weight of nitrogen found in chemical compounds and the heavier free nitrogen found in the atmosphere, Ramsay predicted that nitrogen isolated from the atmosphere was consistently contaminated with a hitherto undiscovered heavy gas. Devising a method that assured the total removal of nitrogen and oxygen from air, Ramsay and Rayleigh found (1894) a chemically inert gaseous element, later called argon, making up nearly 1 percent of the atmosphere. The following year Ramsay liberated helium from the mineral cleveite and thus became the first person to isolate that element. He later (1903) demonstrated that helium, the lightest of the inert gases, is continually produced during the radioactive decay of radium, a discovery of crucial importance to a modern understanding of nuclear reactions.
The positions of helium and argon in the periodic table of elements (a systematic ordering of the elements according to their atomic weights and chemical properties) indicated that at least three more noble gases should exist, and in 1898 Ramsay and the British chemist Morris W. Travers isolated these elements--called neon, krypton, and xenon--from air brought to a liquid state at low temperature and high pressure. In 1910 Ramsay detected the presence of the last of the noble-gas series, called niton (now known as radon), in the radioactive emissions of radium.
Ramsay was elected fellow of the Royal Society in 1888 and was knighted in 1902. His writings include A System of Inorganic Chemistry (1891), The Gases of the Atmosphere (1896), Modern Chemistry, 2 vol. (1900), Introduction to the Study of Physical Chemistry (1904), and Elements and Electrons (1913).
BIBLIOGRAPHY.William Augustus Tilden's Sir William Ramsay appeared in 1918.
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