Rediscovery of the Elements: The Noble Gases--Rayleigh and Ramsay

Rediscovery of the daments
The Noble Gases Rayleigh and Ramsay

James L. Marshall, Beta Eta 1971, and
Virginia R. Marshall, Beta Eta 2003,
Department of Chemistry, University of
North Texas, Denton,TX 76203-5070,
jimm@unt.edu
Henry Cavendish (1731-1810), the discover-
er of hydrogen (phlogiston) in 1766, studied
atmospheric gases for many years. In 1785, he
wondered "... whether there are not in reality
many different substances confounded togeth-
er by us under the name of phlogisticated air
[nitrogen]." By means of electrical sparking he
reacted phlogisticated air with dephlogisticated
air (oxygen) to form nitrous air (nitrogen
oxides) and "continued to spark till no further
diminution took place... only a small bubble of
air remained unabsorbed, which certainly was
not more than 1/120 of the bulk of the phlogis-
ticated air."1
Lord Rayleigh.2 John William Strutt, 3rd
Baron Rayleigh (1842-1919) (Figure 1) was the
second Cavendish Professor of Physics
(1879-1884) at the University of Cambridge
(following James Clerk Maxwell, 1831-1879).
Rayleigh is well known for his publications on
Rayleigh scattering (explaining the blue color of
the sky) and Rayleigh waves (e.g., surface earth-
quake waves). He received the Nobel Prize in
Physics in 1904 for "his investigations of the
densities of the most important gases and for
his discovery of argon."

Figure 2. This is Terling Place, which was built
1770-1771, the home of the Rayleigh family. John
Strutt (1727-1816), and his family moved into
the house in 1773. His grandson was Lord
Rayleigh, John William Strutt, 3rd Baron
(1842-1919); when he retired from Cambridge
University (1884), he returned to continue
research in his private laboratory, the building to
the right, where he discovered argon.
The discovery of argon was prompted by an
attempt to corroborate the postulate of William
Prout (1785-1850), who had proposed" that the
atomic weights of the elements were multiples
of the primary substance hydrogen. Rayleigh
accurately weighed samples of purified hydro-
gen, oxygen, and nitrogen to determine if in
fact hydrogen was a common denominator
(Figures 2,3). He obtained reproducible values
for hydrogen and oxygen, but with nitrogen he
noticed a discrepancy: atmospheric nitrogen
gas weighed more than artificially produced
gas. He sent a letter to Nature4 where he
queried: "I am much puzzled by some recent
results as to the density of nitrogen, and shall
be obliged if any of your chemical readers can
offer suggestions as to the cause...." Rayleigh's
data showed, for a 1800-cc flask,
2.3102+0.0002 grams for atmospheric nitrogen

Figure 1. John William Strutt, Third Baron
Rayleigh, painted by Sir George Reid, 1903.
The original hangs in the Royal Society, London,
Carlton House Terrace, London (N510 30.36
WOO 07.95); a copy resides in the Rayleigh
residence in Terling. He was President of the
Royal Society 1905-1908.
and 2.2990 + 0.0006 grams for nitrogen synthe-
sized from ammonium nitrite and other inor-
ganic precursors. Several persons responded,
including James Dewar (1842-1923), inventor
of the eponymous flask; William Crookes
(1832-1919), discoverer of thallium g; and
William Ramsay (vide infra). Crookes was the

THE HEXAGON/FALL 2012

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Marshall, James L., 1940- & Marshall, Virginia R. Rediscovery of the Elements: The Noble Gases--Rayleigh and Ramsay. Indianapolis, Indiana. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc130206/. Accessed December 25, 2014.