"The powder contains powdered gelatin and flavorings including sugar or artificial sweeteners."
http://en.wikipedia.org/wiki/Jell-O
"Gelatin (spelt "gelatine" in Commonwealth countries, from the French gélatine) is a translucent, colorless, odorless, brittle, nearly tasteless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing."
http://en.wikipedia.org/wiki/Gelatin