In the 17th century, the pursuit of scientific understanding was intertwined with the practices of alchemy. Around 1669, the German alchemist Hennig Brandt made an accidental, yet profound, discovery. Brandt was the first person to isolate an element unknown since antiquity, using a surprisingly common material: human urine. The remarkable substance he discovered was the element phosphorus.
Hennig Brandt’s Alchemical Quest
Hennig Brandt was a merchant in Hamburg, Germany, who turned his attention to the costly endeavor of alchemy. Alchemists sought the legendary Philosopher’s Stone, a mythical substance believed capable of curing all diseases and transmuting base metals into gold. Brandt devoted considerable resources to this search, financing his experimental work using wealth from his marriages.
Brandt chose urine based on alchemical reasoning, which linked its yellowish color to potential value. This suggested to alchemists that it contained the secret ingredient for transmutation. Urine also contained various salts and compounds suitable for distillation, a common alchemical technique. His focus was not on discovering a new element, but on purifying this material to yield the legendary stone.
The Process of Isolation
Brandt’s experimental methodology required immense quantities of starting material and prolonged, intense heating. His process began with collecting large volumes of human urine, which he often allowed to ferment for several days. This aging process was thought necessary, though later research showed fresh urine would have worked just as well.
He then boiled the liquid down significantly, creating a thick, syrupy residue or paste. Brandt likely used over a thousand gallons of urine to yield a small amount of the final product. This concentrated material was combined with other substances, such as sand or charcoal, which acted as reducing agents.
The mixture was placed in a retort and subjected to extreme heat for many hours. Under this intense heat, the phosphate compounds in the urine reacted with the carbon from the charcoal. A white vapor emerged from the apparatus, which was condensed. This vapor solidified into a waxy substance when cooled, yielding the novel element.
Phosphorus: The Light-Bearer
The element Brandt isolated was white phosphorus, which he initially called “cold fire” due to its remarkable physical property. The name phosphorus was later adopted, derived from the Greek words meaning “light-bearer.” The most striking observation Brandt made was the element’s ability to glow in the dark without heat, a phenomenon known as chemiluminescence.
This faint light is produced when white phosphorus reacts slowly with oxygen in the air. The discovery was significant because it marked the first isolation of a new element since ancient times, achieved through verifiable experimental manipulation. Although Brandt sought alchemical transmutation, his method contributed to the transition toward modern chemistry by demonstrating that new substances could be isolated through systematic laboratory work.
Phosphorus is assigned the chemical symbol P and has an atomic number of 15. Due to its high reactivity, the element is never found in its pure, elemental form in nature. Brandt’s discovery demonstrated that even common biological waste contained complex chemistry that could yield entirely new materials.