Sir William Ramsay

Ramsay (1852 - 1916) was Glasgow-born but his main research was at London University. He discovered argon by taking a sample of air and first removing all the oxygen. He then passed the remaining gas (mostly nitrogen) over hot magnesium. Magnesium is reactive enough to combine with nitrogen to leave a solid called magnesium nitride. After doing this repeatedly, he was still left with some gas whose relative mass was 40. This gas didn’t seem to fit into Mendeleev’s Periodic Table!

Later, using newly-discovered techniques for cooling and liquefying gases, he was able to separate other gases from air – neon, krypton, xenon and radon – and it was realised that he had discovered a whole group of elements, none of which had been known to Mendeleev. The final member of the group, helium, had been discovered a few years earlier – in the Sun. Pierre Jules César Janssen had noticed some lines in the spectrum of sunlight that didn’t belong to any known element and suggested a new element, which he called helium, existed in the Sun. Ramsay was the first to recognise helium on Earth so he discovered all of the noble gases (almost).

Sir William Ramsay. Reproduced courtesy of the Library and information Centre, The Royal Society of Chemistry.