salpêtre

Salpêtre, also known as saltpeter, is a common name for potassium nitrate (KNO3). It is a naturally occurring salt that can be found in caves, stables, and as a deposit on old walls, often resulting from the decomposition of organic matter. Historically, salpêtre was of significant importance, primarily for its use in the production of gunpowder. The potassium nitrate in gunpowder acts as the oxidizer, providing the oxygen necessary for the rapid combustion of charcoal and sulfur.

Beyond its use in explosives, salpêtre has also found applications in agriculture as a fertilizer due to its potassium and nitrogen content. It was also historically used in food preservation, particularly for curing meats, though its use in this application has largely been superseded by other nitrates and nitrites. In medicine, diluted solutions of potassium nitrate have been used as a mouthwash for soothing sore gums. The mining and production of salpêtre were important industries in various historical periods and regions, contributing to both military power and agricultural development. Modern production of potassium nitrate involves chemical synthesis rather than extraction from natural deposits.