The medicinal history of phosphorus

Elemental yellow phosphorus was isolated by the Hamburg merchant Hennig Brandt (or Brand) in 1669. He allowed urine to ferment, boiled it down and dry-distilled the residue with potassium hydrogensulfate. The product, the more reactive of the two common allotropes of phosphorus, spontaneously inflamed in air (at ca 37°C) and glowed in the dark. With such seemingly 'miraculous' properties some experimentalists speculated that the new element might have a beneficial medical effect, if applied in the right doses to the right diseases. The search was on for a medicinal use for phosphorus and this continued up to the start of the 20th century.