White phosphorus (WP) is an allotrope of phosphorus known for its toxicity, pyrophoric nature, and intense luminescence. It exists as a waxy, translucent solid that spontaneously ignites upon contact with air at temperatures as low as 30 degrees Celsius. Its historical journey traces a path from a mystical laboratory curiosity to a widespread industrial agent and, eventually, a controversial military munition. The initial isolation of this unique element occurred in the 17th century, a time when chemistry was still deeply intertwined with the ancient practice of alchemy.
The Alchemist’s Discovery in 1669
The first known isolation of white phosphorus took place around 1669 in Hamburg, Germany, by the alchemist Hennig Brand. Brand, a former military officer, was focused on the long-sought alchemical goal of creating the Philosopher’s Stone. This mythical substance was believed to possess the ability to transmute base metals into gold.
His experimental method involved processing large quantities of human urine, a material believed to contain alchemical secrets. Brand spent time boiling down and concentrating vast amounts of urine to produce a thick, tar-like residue. This residue was then mixed with sand and charcoal and heated intensely within a furnace.
After hours of heating, a white vapor formed and condensed into a waxy liquid that glowed brightly in the darkness of his laboratory. Brand had successfully isolated the new substance, which he initially called “cold fire” due to its eerie, self-illuminating property. He named his discovery phosphorus, derived from the Greek phrase meaning “light-bearer.”
The German alchemist kept his precise method a closely guarded secret, hoping to use the luminous material to achieve gold production. Despite his efforts, the substance failed to produce gold, and Brand eventually sold the secret of its preparation to other early chemists. This accidental discovery marked the first isolation of a chemical element that had not been known since antiquity.
Industrial Application and the Match Industry
For over a century following its discovery, white phosphorus remained a laboratory curiosity or a substance used in public demonstrations. Its first widespread commercial application emerged in the 19th century with the development of the friction match. Early versions of matches, such as the “lucifer matches” introduced in 1826, were unreliable, but the addition of white phosphorus six years later revolutionized the product.
White phosphorus was ideal for this purpose because of its low ignition temperature, which allowed the “strike-anywhere” match to ignite easily when rubbed against any rough surface. The immense demand for this convenient new product led to the expansion of match factories across the globe. Workers, often women and children, handled the toxic chemical in poorly ventilated conditions.
The industrial production process exposed workers to white phosphorus vapor, which led to a severe occupational disease known as “phossy jaw,” or phosphorus necrosis of the jaw. The disease typically began with a persistent toothache, followed by swelling of the gums and the formation of pus-filled tracts leading to the bone. Over time, the jawbone would decay and die.
The first case of phossy jaw was diagnosed in 1839, and the condition quickly became recognized as a consequence of white phosphorus exposure. Reformers and public outcry eventually led to international action to protect workers. The International Berne Convention of 1906 prohibited the use of white phosphorus in the manufacture of matches, pushing the industry to adopt the safer red phosphorus alternative.
Weaponization and Early Military Deployment
The unique chemical properties of white phosphorus made it an attractive material for military applications. The substance is highly pyrophoric, spontaneously igniting upon exposure to oxygen, making it difficult to extinguish once burning. Its combustion creates a dense cloud of white phosphorus pentoxide, which is an effective smoke agent.
The first significant military use of white phosphorus occurred during World War I, when both the Allied and Central Powers began to deploy it. The British Army introduced the first factory-built white phosphorus grenades in late 1916. These munitions were primarily used to create thick, immediate smoke screens to conceal troop movements, obscure positions, and mask attacks.
White phosphorus was also deployed in artillery shells and mortar rounds, utilizing its ability to generate an instantaneous blanket of smoke. This smoke-screening capability proved tactically valuable for hiding friendly forces or marking targets. The substance’s incendiary effect was initially a secondary consequence.
The intense heat and chemical damage caused by white phosphorus cemented its role as an incendiary and anti-personnel weapon. It burns at temperatures exceeding 1,300 degrees Celsius and produces severe thermal and chemical burns that penetrate deep into tissue. Its use expanded in World War II, where it was utilized in grenades, shells, and bombs for both smoke generation and destructive incendiary properties.