From the Middle Ages to the late 17th century, the so-called “philosopher’s stone” was the most sought-after goal in the world of alchemy, the medieval ancestor of chemistry. According to legend, the philosopher’s stone was a substance that could turn ordinary metals like iron, tin, lead, zinc, nickel or copper into precious metals like gold and silver. It also acted as a precious 26 of life, with the power to cure illness, renew the properties of youth and even grant immortality to those who possessed it. The philosopher’s stone 27 a stone at all, but a powder or other types of substance. In their quest to find it, alchemists examined countless substances in their laboratories, building a base of knowledge that would 28 the fields of chemistry, pharmacology and metallurgy. Many of the Western world’s most 29 minds searched for the philosopher’s stone over the centuries, including Roger Boyle, the father of modern chemistry, and even Sir Isaac Newton, whose secretive attempts in alchemy are well known by now. Long before Newton, however, there was Nicolas Flamel, a French bookseller who lived in Paris during the 14th and early 15th centuries. In 1382, Flamel claimed to have transformed lead into gold after 30 an ancient mystic book of alchemy. Harry Potter fans might recognize the name, as J.K. Rowling incorporated Nicolas Flamel into the first book in her world-famous series.