Potassium nitrate, also known as niter or saltpeter, is a chemical compound composed of potassium (a soft, light, sliver-white metal) and the gasses nitrogen and oxygen (both colorless and odorless). When combined, the elements produce a whitish substance. Potassium nitrate has been used for several centuries, most famously in the manufacture of gunpowder, also called black powder.
The earliest use of potassium nitrate can be traced to ancient China around the 3rd century B.C. The Chinese discovered that when about 15 percent charcoal and 10 percent sulfur is mixed with about 75 percent potassium nitrate, it produces gunpowder, a substance with explosive power. It has been through its history by nicknames such as “Chinese snow” and “the devil’s distillate.”
By the 11th century A.D., inventors were using potassium nitrate for their explosive innovations, and by the 13th century, its spread throughout Europe was complete. It took another century for Europeans to truly exploit the use of potassium nitrate for weaponry, manufacturing guns and cannons with the necessary gunpowder.
By then, people wanted to purify the compound. The earliest evidence of this is a book written in 1270 by Arab chemist and engineer Hasan al-Rammah, in which he describes the use of wood ashes–harboring potassium carbonate–to remove calcium and magnesium salts from potassium nitrate.
19th and 20th Centuries
People began to produce potassium nitrate on an industrial scale by the 1900s, and the chemical compound was even more integral in some of the world’s most devastating wars, namely World War I (1914 to 1918). Gunpowder was beginning to show its age, though, and was no longer able to keep pace with advancing technology. It produced a lot of white smoke during ignition, gave out a very restrictive residue with the first few shots and was very easy to dampen. Dynamite and TNT eventually replaced gunpowder as primary blasting explosives.
Potassium nitrate is one of the major components used today in artillery-shell primers and hand-grenade fuses. It is also used for fireworks such as smoke bombs, which are devices that vary in application from military use to paintball games.
Since it is made up mostly of potassium, an element essential for the growth of plants, potassium nitrate is also used in agriculture. Some toothpastes are manufactured with potassium nitrate to reduce tooth sensitivity. In the Middle Ages, potassium nitrate was used as a food preserver, and even though it has never been proven, some people believe that the ingestion of the compound can decrease one’s sex drive.