Which element was discovered in 1772 by Daniel Rutherford?

Daniel Rutherford discovered nitrogen in 1772.

Rutherford isolated the gas while studying air at the University of Edinburgh. He confined a mouse in a measured quantity of air until it died, then used a candle and burning phosphorus to remove the oxygen that supported life and combustion. The remaining gas did neither, so he called it “noxious air” or “phlogisticated air.”

Rutherford did not understand nitrogen as a distinct chemical element in the modern sense, because the phlogiston theory still shaped scientific thinking. Other researchers, including Carl Wilhelm Scheele and Henry Cavendish, investigated the same unreactive part of air. Antoine Lavoisier later called it azote, meaning “lifeless,” while the modern name nitrogen reflects its role in forming nitrates.

Nitrogen makes up about 78% of Earth’s atmosphere by volume. It is relatively unreactive as N₂, but nitrogen compounds are essential to proteins, DNA and fertilizers. A common mix-up is crediting Rutherford with discovering oxygen; his experiment actually removed oxygen and revealed the gas left behind.