S.O.T.T: It's time to buy a lot of candles. And if we light them with matches, it will only be possible because of the anniversary in question. It's happy 350th birthday to the discovery of phosphorus, an element that is essential for life as we know it.
The story of how the 15th element on the periodic table was discovered stands as one of the great accidents of human endeavour - the chemist's equivalent, perhaps, of Columbus setting out for India only to find the Americas by mistake. In the case of phosphorus, the explorer was Hennig Brand, a 17th-century alchemist and merchant from Hamburg, Germany.
Brand had been trying to achieve one of the great goals of alchemy, to make the philosopher's stone. Alchemists thought this was the elixir of life, capable of transforming lead into gold. But where to find this legendary substance?
Brand was convinced that the answer was human urine, for two good reasons. First, gold and urine were a similar colour. Second, urine came from the human body, which was regarded by alchemists as a work of perfection. The actual process that Brand set up in 1669 was remarkable. One would struggle to repeat it in a garden shed nowadays - unless you had neighbours who were willing to tolerate extremely bad smells. Brand concentrated large amounts of human urine and left it to ferment. He then heated the residues, performing dry distillation, as depicted below in the 1795 Joseph Wright painting, the Alchemist in Search of the Philosopher's Stone.
Brand was left with a white waxy solid which glowed in the dark even in a closed bottle, and combusted spontaneously with a very bright white flame when exposed to air. Intrigued by these properties, he named it phosphorus because this meant "light bearer" in Greek. He attempted many times to use the substance to transform lead into gold, but to no avail.
Nonetheless, phosphorus is biologically vital. The average human body contains about 0.5kg of phosphorus, most of it in the form of phosphate to make bones and teeth strong. Phosphorus also crucially holds together DNA and RNA molecules - the backbone of these long chain-like structures contains two phosphate groups per pair of nucleic bases. Without phosphorus, it is hard to imagine any kind of life at all....read more>>>>....
