Chromicized Gut.
—Gut to be thus prepared should be wound in single layers on spools and immersed in a solution of potassium bichromate 1.5 to 2.5, carbolic acid and glycerin each 10, and water 1000 parts. It is allowed to remain in this solution for twenty-four hours, then dried and boiled in water, or in alcohol under pressure, in which it is subsequently stored. According to the length of exposure and the strength of the solution, this gut will resist absorption from ten to thirty days.
Iodine Gut
is growing in favor with some surgeons. It is prepared by immersing catgut in a 10 per cent. solution of iodine, in which it is kept for a week. After removal it is allowed to dry and is stored dry, but should be kept protected from exposure.
Silkworm-gut
may be boiled in a 2 per cent. lysol solution for one hour, which makes it pliable. Sometimes it is convenient to have it stained black in order that the sutures may be better distinguished when removed. In this case it is allowed to stand in a 1 per cent. silver nitrate solution for from twelve to twenty-four hours. This gives it an almost black stain, but tends to make it more brittle. It may be kept in alcohol, or dry in a sterile receptacle.
Silk.
—Silk should be spooled loosely, boiled in a similar solution for one-half hour, and again in plain water just before using. It may be stored dry or in alcohol. It may be also stained black.
Celluloid Thread.
—This should be washed and scrubbed in green soap and hot water, after which it is spooled, and then boiled for thirty minutes. It may be stored dry or in alcohol. This is a linen thread covered with a film of celluloid.