At a time when the periodic table seemed complete, William Ramsay’s curiosity uncovered an entire hidden family of elements, a momentous discovery that continues to shape and illuminate our world.

There is a difference between discovery and invention. A discovery brings to light what existed before, but what was not known; an invention is the contrivance of something that did not exist before.

William Ramsay, The Gases of the Atmosphere: The History of Their Discovery (4th edition, 1915)

In the late nineteenth century, most scientists believed the periodic table was close to completion. Yet, lurking in our atmosphere lay an unsuspected group of elements that were almost stumbled upon by the meticulous UCL chemist William Ramsay (1852-1916). 

Born in Glasgow, Ramsay came from a family of scientists. His father, William Ramsay, was a civil engineer and his uncle, Sir Andrew Ramsay, was the first Professor of Geology at UCL. He showed a great interest in science from a young age, using equipment and chemicals acquired by his father to make fireworks.  

Ramsay was appointed Chair of Chemistry at UCL in 1887. Nicknamed “the Chief”, he was an inspirational teacher and admired by his students. It was soon after his appointment that John William Strutt, 3rd Baron Rayleigh spotted a minute difference in the density of the nitrogen, depending on how it was obtained. Ramsay began to suspect that there must be a mysterious “impurity” in the air. Working in parallel with Rayleigh, Ramsay isolated a gas – a new element – that seemed to display no chemical reactivity at all. They named it argon, meaning “the lazy one”. 

Argon was just the beginning. Over the next few years, Ramsay identified helium, neon, krypton and xenon – a whole group of unknown inert gases that formed an entirely new column on the periodic table. 

Black and white photo of William Ramsay in his laboratory
William Ramsay in his UCL laboratory with mercury piston pumps visible / UCL Special Collections, UCLCA/7

In 1904, Ramsay was the first man in Britain to receive the Nobel Prize in Chemistry for this world-changing discovery, alongside Rayleigh who received the Nobel Prize in Physics. He was also the first of many Nobel Laureates at UCL. 

The original glass tubes Ramsay used to isolate and collect his samples are still at UCL today, glowing red and yellow, purple and green, more than a century later. 

Ramsay’s noble gases continue to have a major impact on our daily lives. Liquid helium is used in MRI scanners. Argon makes the arcs for stitching together the steel structures of ships, railways and skyscrapers. Argon, krypton and xenon are widely used in double-glazing. What we call “neon” lights seldom are these days, yet their glow in the darkness is a brilliant reminder of the progress that comes from blue‑skies research and noticing what others overlook.

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