Nitrogen is a colorless, odorless gas that makes up roughly 78% of the Earth’s atmosphere, making it the most abundant element in the air we breathe. Its chemical inertness meant it remained unrecognized as a distinct substance until the late 18th century. The naming of this element involved a historical conflict between two proposed names, each reflecting a different understanding of its nature. Tracing the etymology of the word “nitrogen” reveals a fascinating history rooted in early pneumatic chemistry and the revolution in chemical nomenclature.
The Initial Discovery and Isolation of “Mephitic Air”
The first isolation of the gas occurred in 1772 by the Scottish physician Daniel Rutherford, who was a student of the chemist Joseph Black. Rutherford conducted experiments on air that remained after removing the components known to support life and combustion. He showed that when a mouse or a candle was placed in a sealed container, the remaining gas could no longer sustain either life or fire.
He then removed the carbon dioxide—or “fixed air”—produced by the breathing or burning by passing the residual gas through an alkali solution. The gas that remained was a new, distinct substance that still refused to support respiration. Rutherford called this residual gas “noxious air” or mephitic air, with mephitic meaning poisonous or foul-smelling, because he observed its inability to sustain life.
Around the same period, other chemists, including Henry Cavendish and Joseph Priestley, were also performing similar experiments and isolating the same gas. Priestley referred to it as “phlogisticated air,” based on the prevailing phlogiston theory of combustion. Rutherford is generally credited with the discovery because he was the first to publish a detailed description of the gas in his doctoral dissertation in 1772. This initial stage established the gas’s primary observed property: its inertness.
The French Designation: Azote (No Life)
The first formal attempt to name the newly isolated gas came from the French chemist Antoine Lavoisier, a central figure in the chemical revolution. Lavoisier, along with other French chemists, sought to create a new, rational system of chemical nomenclature based on the composition and properties of substances. Lavoisier recognized that the gas did not support life, and its inert nature was its most striking feature.
He proposed the name azote, which he derived from the Greek prefix a- meaning “not” or “without,” and zoē meaning “life.” The name literally translates to “without life.” This designation was chosen to highlight the gas’s inability to support respiration or combustion, contrasting it with oxygen, which Lavoisier had named the “acid-former.”
The name azote was widely adopted in many other languages, including French, Italian, and Russian. Furthermore, the name’s influence persists in English chemical terminology, as the prefix azo- is used in the names of many nitrogen-containing compounds, such as azides and azo dyes.
The English Designation: Nitrogen (Nitre-Forming)
The name that eventually became the English standard, nitrogen, was coined in 1790 by the French chemist Jean-Antoine Chaptal. Chaptal’s proposal focused not on the gas’s lack of biological activity but on its specific chemical composition and origin. He was observing that the element was a fundamental component of nitric acid and nitrates.
The term nitrogen is a compound word derived from two Greek roots: nitron and -gen. Nitron referred to natron, or the mineral saltpeter (potassium nitrate), which was a substance long known to contain the element. The suffix -gen comes from the Greek term meaning “forming” or “generating.”
Therefore, nitrogen translates to “nitre-former” or “nitre-generating.” This name highlighted the element’s role in the formation of nitric acid and the saltpeter used in gunpowder and fertilizers.