Hennig Brand discovered phosphorus in 1669, in Hamburg, Germany, preparing it from urine. (Urine naturally contains considerable quantities of dissolved phosphates.) Brand called the substance he had discovered ‘cold fire’ because it was luminous, glowing in the dark. He did not reveal his method publicly, choosing instead to sell it to Johann Daniel Kraft and Kunckel von Lowenstern. For further payment he also revealed his secret to Gottfried Wilhelm Leibniz, better known for discovering calculus independently of Isaac Newton. Leibniz, also thinking as an alchemist, mistakenly believed Brand might be able to discover the philosophers’ stone by producing a large quantity of phosphorus. Brand’s method is believed to have consisted of evaporating urine to leave a black residue that was then left for a few months. The residue was then heated with sand, driving off a variety of gases and oils which were condensed in water. The final substance to be driven off, condensing as a white solid, was phosphorus. This was a typically alchemical method – alchemists examined the properties of body fluids, hoping to better understand living things in their search for the philosophers’ stone, which they believed offered the prospect of eternal life. Brand’s method became more widely known in 1737 when an unknown person sold it to the Academy of Sciences in Paris. Phosphorus was produced by this method until the 1770s when Swedish scientist Carl Wilhelm Scheele – the discoverer of chlorine and one of oxygen‘s independent discoverers – found that phosphorus could be prepared from bone.(3) The name comes from the Greek word ‘phosphoros’ meaning bringer of light.