A yellow crystalline powder, in which iodine, carbon, and hydrogen combine to form a valuable compound, with a somewhat offensive odour and powerful antiseptic properties. In horse practice it is used in the treatment of foul ulcers and unhealthy wounds. In cases of ozena it is injected up the nostrils by means of an insufflator. Mixed with oxide of zinc, flour, and other diluents, it is dusted over abraded surfaces and injured tissues as a preventive of putrefaction where septic influences are known to be at work.