When the Europeans discovered Latin America, they noticed the locals were able to make small objects from a tree's sap, called the Rubber tree or caucho in Quechuan. In the 17th century a British scientist mixed rubber with naphtha which resulted in a liquid that made clothes waterproof, but also smelly and sticky. Charles Goodyear was experimenting with rubber and Nathaniel Hayward told him to sprinkle flowers of sulphur on rubber to reduce its stickiness. Goodyear spent years improving this process called vulcanization. Thomas Hancock claimed he had finally gained control over rubber and registered a patent for vulcanization. In 1860, Charles Greville Williams discovered the rubber molecule, which he called isoprene. Gustav Bouchardat combined isoprene with hydrochloric acid which created a paste-like rubber. 30 years later, Fritz Hofmann created the first artificial rubber. Following WWI, Hermann Staudinger suggested the rubber substance was made of a polymer, which paved the way for many inventions.