The word nitrate connects modern industrial chemistry to ancient Egyptian religious practice. The chain runs: Egyptian nṯry (divine, pure) became Greek nitron (native soda, natron), became Latin nitrum, became Old French nitre (saltpeter), became the base for the chemical term nitrate, coined in the 18th century with the suffix -ate denoting a salt of an acid.
The Egyptian nṯry described natron — a naturally occurring mixture of sodium carbonate and sodium bicarbonate found in dried lake beds, particularly in the Wadi Natrun northwest of Cairo. The Egyptians considered natron divine or sacred because of its purifying properties: it was essential to mummification, where it desiccated the body and prevented decay. Natron was also used in ritual purification, cleaning, and even as an early toothpaste.
Greek speakers adopted the Egyptian word as nitron, applying it to the mineral substance. The word traveled through Latin as nitrum, eventually narrowing in European languages to describe specifically saltpeter (potassium nitrate, KNO₃) — a mineral salt that was chemically related to but distinct from the original Egyptian natron.
Saltpeter was one of the most strategically important substances in pre-industrial Europe. As a key ingredient of gunpowder (along with sulfur and charcoal), saltpeter was essential to military power. Nations invested enormous resources in locating, mining, and even manufacturing saltpeter — some European governments granted collectors the right to enter private property and scrape nitrate-bearing deposits from cellar walls and barn floors.
The element nitrogen, discovered by Daniel Rutherford in 1772, was named by Jean-Antoine Chaptal in 1790 from French nitrogène — literally nitre-former — because nitrogen was a component of nitre (saltpeter). The chemical term nitrate followed shortly after, describing salts containing the nitrate ion (NO₃⁻).
Today, nitrates are primarily associated with agriculture (as fertilizer), food preservation (sodium nitrate in cured meats), and explosives (ammonium nitrate). The Haber-Bosch process for synthesizing ammonia and its conversion to nitrate fertilizers is credited with enabling the population boom of the 20th century — roughly half the nitrogen atoms in a modern human body were fixed by industrial processes.