Читать книгу The Practical Ostrich Feather Dyer - Alexander Bartlett Paul - Страница 11

This dyestuff, known as red chrome and bichromate and often times simply as chrome, consists in one equivalent of potash, with two equivalents of chromic acid. It contains no water, and consequently cannot lose any weight by exposure to heat or dry air. It will not attract moisture from a damp atmosphere. It dissolves readily in ten times its weight of cold water, and is insoluble in alcohol. It forms bright red crystals, and the solution is of a deep orange yellow. Bichromate of potash is a most powerful oxidizing agent, and produces very complex and interesting changes in tinctorial bodies. It is an intense poison. Its most extensive application is now in the production of blacks, along with logwood; indeed, without its aid it would be next to an impossibility to produce a glossy and permanent black on ostrich feathers. In giving depth of shade to all dark colors it is used in preference to any thing else, and I have never found any to contain any adulteration that was perceptible, or that was a hindrance to its good qualities. It is used in ostrich feather dyeing always in a diluted form, in a very high temperature of water.