John Wesley Hyatt (1837-1920), US inventor. Hyatt is best known for discovering a method to simplify the production of the plastic celluloid. He found the method in 1868 while researching a substitute material for ivory billiard balls. He spilt a bottle of collodion, and discovered that it dried into a tough and flexible film. After further experimentation and addition of different materials, he ended up with a form of celluloid that could be molded using heat and pressure, one of the first thermoplastics. The major application of the discovery was in strip format as the first flexible photographic film. By 1900, celluloid was being used in movie films and still photography.