how was nitrogen discovered

Nitrogen was discovered in 1772 by Scottish chemist Daniel Rutherford. He isolated nitrogen by removing oxygen and carbon dioxide from air, leaving a residual gas that did not support combustion or life, which he called "noxious air." Although Henry Cavendish, Joseph Priestley, and Carl Scheele were also working on identifying this gas around the same time, Rutherford is credited with the discovery as he was the first to publish his findings. The name "nitrogen" was later coined in 1790 by French chemist Jean Antoine Claude Chaptal, meaning "saltpetre forming," derived from nitre (potassium nitrate).