INCOMBITS'TIBLE FABRICS have of late years become of great importance, owing to the terrible frequency of death from the ignition of clothing; the search, however, after some means of rendering garments incombustible has continued from a very early period (see Beckmann's lEltorg of _Inventions). After many more or less successful attempts by Gay-Lussac and other chemists, Messrs. Versmann g.t Oppenheim communicated to the British association at Aberdeen, in 1859, the results of a series of experiments for render ing linen, calico, muslin, and all other vegetable fibers uninflammable.* They found that many salts possessed this power, but at the same time some of these injured the fabric, spoiled the color, or were so very expensive as to render their general use impossible. Two, however, viz., tungstate of soda and sulphate of ammonia, produced the best results without injuring the tissue or color of the fabric. The first of these acts physically by preventing contact with the air, and does not interfere with the processes of ironing and starching; it is therefore preferable for goods requiring washing. The best method of applying it is by mixing in the proportion of 4 oz. of tungstate of soda to 1 dram of
phosphate of soda (to prevent the formation of a partially insoluble bitungstate), and dis solving the whole in an imperial pint of water. For fabrics which are worn without pre vious washing, sulphate of ammonia is preferable, and a solution containing 7 per cent of the crystalline salt is a perfect preservative. In printed muslins of a madder purple, however, a slight paleness of color is produced, but in no other case is the color affected, nor does it interfere with the ironing process. It is to be regretted that these simple and efficacious preservatives have not come into general use.—The incombustible fabrics of the ancients were formed of asbestos (q.v.).
a tax imposed on all persons having incomes above a certain amount, whether from lands or labor. Various acts have passed from time to time to impose this tax—the first introduced by Pitt, and latterly revived in 1842 by sir Robert Peel, since which date it has been continued—the fairness and public policy of which have given rise to long and endless controversy. See TAXATION.