The density of rubber is dependent upon the kind of rubber; hard rubber has a density of 74 lb/foot cubed, while soft commercial rubber has a density of 69 lb/foot cubed and pure gum rubber has a density of 57-58 lb/foot cubed. The term "rubber" has had many meanings over the years, including as a reference to a horse towel in 1598 and a polished brick in 1744 before it came to mean the elastic substance used today.
Rubber became a popular part of fashion when Arthur Wellesley, the 1st Duke of Wellington, was able to pioneer a new version of the popular cavalry-style boot (called a Hessian boot for its popularity among German officers in the Hesse region) by bringing it upward to protect the knee. The rubber Wellington boot was made when Hiram Hutchinson stole the idea for his rubber boot factory in France. It was an immediate hit for its practical purposes that is still sold today.
Rubber is most often made from natural rubber, which comes from the latex emulsion collected on the rubber tree or Hevea Brasiliensis tree. The tree grows in large plantations in Thailand, Indonesia and Malaysia. The United States has to import most of its rubber as these trees only grow in tropical climates.