Have you ever wondered how a balloon is made? A balloon is a flexible inflatable bag that expands when filled with oxygen or the more efficient helium gas. The first balloon was invented by Michael Faraday in 1824 and was made of dried animal bladder. Today, balloons are made from latex which comes from rubber trees. The low cost of the balloon means it is produced on a large scale for numerous applications. Most balloons are used for recreational and decorative purposes and others for medical treatment and scientific experiments.