Sir William Ramsay (1852-1916) and Lord Rayleigh (born John William Strutt, 1842-1919) published their discovery of argon in 1895.
In terms of the periodic table, the discovery was significant. It presented scientists with a new element for which there was no place in the periodic table. But it also suggested that there should be a family of such elements, and led to the discovery of other noble gases.
Ramsay and Rayleigh were both awarded Nobel Prizes in 1904.
Rayleigh was awarded the physics prize for discovery of argon.
Ramsay was awarded the chemistry prize for argon and the family of noble gases.
Read this illustrated biography of Rayleigh.