To vulcanize rubber means to heat it with sulfur to make it stronger, more durable, and more elastic. Before vulcanization, natural rubber becomes sticky and melts in hot weather, then cracks and breaks in cold weather. After vulcanization, rubber keeps its useful properties in all temperatures.

Charles Goodyear discovered this process by accident in 1839 when he dropped rubber mixed with sulfur onto a hot stove. He noticed the heated mixture didn't melt like regular rubber. This discovery transformed rubber from a curious but impractical material into one of the most useful substances in modern life. Vulcanized rubber made possible everything from car tires to waterproof boots to the rubber bands you might use to bundle papers together.

Without vulcanization, we wouldn't have reliable tires, and cars as we know them wouldn't exist today.