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Creosote

wood, temperature, carbolic and distillation

CREOSOTE (Greek a product of the destructive distillation of wood or coal especially the former. Wood-tar creosote, when freshly prepared, is an oily, transparent liquid, colorless, and of indefinite composition, containing many different chemical substances, chiefly belonging to the aromatic series. It was discovered by . Reichenbach in 1832, and for a considerable time was confused with carbolic acid. It has a strong, smoky smell, burns with a sooty flame and refracts light powerfully. It has been greatly used as an antiseptic, both in dentistry and general surgery, and also for the preservation of meat, from which circumstance it derives its name. Its preservative action is so marked that meat will not decay after it has been treated superficially with a 1 per cent solution. Coal-tar creosote is obtained in the distillation of coal-tar, and is usually under stood to include that portion of the distillate which comes over at temperatures between 400° and 760° F., although different temperature limits are used by different distillers. Coal-tar creosote (technically known as °creosote is used for the preservation of timber. For this purpose the timber to be treated is placed in an air-tight cylindrical iron tank, from which the air is exhausted by means of an air-nump.

The creosote is then introduced at a temperature slightly higher than 212° F., and the temperature and vacuum are both maintained until the mois ture of the wood has been entirely vaporized, and the wood itself impregnated with the oil.

Creosote is also used for fuel, for softening pitch and as an antiseptic application for the treatment of certain diseases of cattle and sheep. It is but slightly soluble in water, though it mixes readily with alcohol, ether and many other organic fluids.

For medical purposes °creosote is a mixture of phenols, chiefly guaiacol and creosol, ob tained during the distillation of wood tar, pre ferably of that from the beech.* In its phys iological action, being a mixture of phenols, it naturally resembles carbolic acid very closely. It is now widely used as a stimulant to digestion and as a tonic in tuberculosis and other wasting diseases. The vapor is of service when inhaled, in diminishing the mixed infections that occur in many cases of tuberculosis. Creosote is not specific for this disease. It is very widely em ployed in bronchitis and is of service in nausea and as an intestinal antiseptic. Poisoning by creosote resembles that of carbolic acid (q.v.).