Organosulfur compounds are used in pharmaceuticals, dyestuffs, and agrochemicals. Sadler's works produced synthetic aniline and alzarine dyestuffs and distilled tar. Polymorphism is relevant to the fields of pharmaceuticals, agrochemicals, pigments, dyestuffs, foods, and explosives. ICI Dyestuffs at Hexagon House, in Blackley in north Manchester, discovered Procion dyes. By the 1870s commercial dyeing with natural dyestuffs was fast disappearing. Both insects produce red dyestuffs that are also commonly called cochineal. The chemical is changed to other substances (dyestuffs and "m"-nitrophenol) during the dyeing process. Dyestuffs including carmine (cochineal), shellac, and kermes have been made from the bodies of insects. Sulfuric acid is also important in the manufacture of dyestuffs solutions. Textiles, glass, dyestuffs, olives, wine, sesame oil and sugar were exported; silk was particularly prized. They occur widely in the drugs, herbicides, plant growth regulators, and dyestuffs. Certain indole derivatives were important dyestuffs until the end of the 19th century. The benzene rings in indigo can be modified to give a variety of related dyestuffs. Materials used include the wood, tannins and dyestuffs. To overcome this deficiency, dyestuffs containing two (or more) different reactive groups were developed.