Surgical suture father of medicine, Hippocrates, described suture techniques, as did the later Roman Aulus Cornelius Celsus. The 2nd-century Roman physician Galen described gut sutures. In the 10th century, the catgut suture along with the surgery needle were developed by Abulcasis. The catgut suture was similar to that of strings for violins, guitar, and tennis racquet and it involved harvesting sheep intestines. Joseph Lister endorsed the routine sterilization of all suture threads. He first attempted sterilization with the 1860s "carbolic catgut," and chromic catgut followed two decades later. Sterile catgut was finally achieved in 1906 with iodine treatment. The next great leap
Musical instrument classification ways, having finger-holes to control pitch, rather than valves. Keyboard instruments do not fit easily into this scheme. For example, the piano has strings, but they are struck by hammers, so it is not clear whether it should be classified as a string instrument or a percussion instrument. For this reason, keyboard instruments are often regarded as inhabiting a category of their own, including all instruments played by a keyboard, whether they have struck strings (like the piano), plucked strings (like the harpsichord) or no strings at all (like the celesta). It might be said that with these extra categories,