How did Hennig Brand discover phosphorus in 1669?

In 1669, the German alchemist Hennig Brand discovered phosphorus while searching for the philosopher’s stone, a substance believed to turn base metals into gold.12

His process involved the following steps:

• Preparation: Brand collected approximately 50 buckets of urine and allowed the liquid to putrefy until it "bred worms".2
• Distillation: He boiled the putrefied urine down into a thick paste.2
• Heating: This paste was then heated with sand, which allowed him to distill a white, waxy material from the mixture.12

Brand named the substance phosphorus, meaning "light bearer," because it exhibited the unique property of glowing in the dark. Although he attempted to keep his methodology secret, his discovery marked the first time an element had been isolated by a known individual.12