English physicist · 1842–1919
Lord Rayleigh
Lord Rayleigh co-discovered argon in 1894 because of a difference in the fourth decimal place. He won the 1904 Nobel Prize in Physics for it.
How Argon was found
Measuring the densities of gases with great care, Rayleigh found that nitrogen taken from air weighed about half a per cent more than nitrogen made from ammonia. Rather than dismiss the gap, he published it in Nature in 1892 and asked for explanations.
William Ramsay suspected a heavier gas hidden in the air. Rayleigh repeated an old experiment by Henry Cavendish, sparking air with oxygen to remove the nitrogen, and was left with a small bubble that would not react. In 1894 the two announced argon.
Shared the credit
The discovery is credited jointly to these scientists.
Life and career
Born 1842 · Died 1919
Born John William Strutt in Essex, he inherited the title of Baron Rayleigh. He studied mathematics at Cambridge and built a private laboratory at his estate at Terling.
He explained why the sky is blue (Rayleigh scattering), wrote a classic textbook on sound and succeeded James Clerk Maxwell as head of the Cavendish Laboratory. He later served as President of the Royal Society and Chancellor of Cambridge University.
Also known for
- Rayleigh scattering, which explains the blue sky
- The Theory of Sound
- 1904 Nobel Prize in Physics
Discovered in the same era
Other elements identified within ten years of 1894.