Speculating on the nature of radioactive emanations, in his Nobel lecture http://nobelprize.org/nobel_prizes/chemistry/laureates/1904/ramsay-lecture.html, December 12, 1904.
William Ramsay: 1 quote0 likes
Sir William Ramsay, was a Scottish chemist who discovered the noble gases and received the Nobel Prize in Chemistry in 1904 "in recognition of his services in the discovery of the inert gaseous elements in air" . After the two men identified argon, Ramsay investigated other atmospheric gases. His work in isolating argon, helium, neon, krypton and xenon led to the development of a new section of the periodic table.

Speculating on the nature of radioactive emanations, in his Nobel lecture http://nobelprize.org/nobel_prizes/chemistry/laureates/1904/ramsay-lecture.html, December 12, 1904.