Catgut down to the desired diameter using a centerless grinder. After drying and polishing, workers bleach and disinfect the strings using sulfur dioxide, dye them if necessary, and sort them into sizes. Catgut sutures are normally treated with a chromium salt solution to resist body enzymes, to slow the absorption process, and are called catgut chromic sutures—whereas untreated catgut sutures are called catgut plain sutures. Catgut Catgut is a type of cord that is prepared from the natural fibre found in the walls of animal intestines. Catgut makers usually use sheep or goat intestines, but occasionally use the intestines of cattle,
Koto (instrument) Koto (instrument) The is a Japanese stringed musical instrument derived from the Chinese zheng, and similar to the Mongolian yatga, the Korean gayageum, and the Vietnamese đàn tranh. The koto is the national instrument of Japan. Koto are about length, and made from "kiri" wood ("Paulownia tomentosa"). They have 13 strings that are usually strung over 13 movable bridges along the width of the instrument. There is also a 17-string variant. Players can adjust the string pitches by moving the white bridges before playing. To play the instrument, the strings are plucked using three finger picks (thumb, index finger, and