Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Claviharp Claviharp The claviharp is a 19th-century musical instrument that combined a harp with a keyboard. J. C. Dietz invented the instrument in 1813 CE. His grandfather was one of the first upright piano manufacturers. Struck by what he saw as difficulties and defects of the harp, in 1810, he built an "instrument à cordes pincées à clavier", which connected a keyboard to the harp strings. He made the instrument to address limitations of the harp—susceptibility of catgut strings to atmospheric change, inconsistency of sound as finger motion varies, limited diatonic scale (without pedals), and lack of dampers. The claviharp's keyboard