SMOKELESS POWDER. An explosive sub stance that burns without developing much smoke, and is used chiefly for military purposes. The history of smokelems powders begins with the discovery of mercuric fulminate in 1800, and is continued by various attempts to substitute am monium nitrate for potassium nitrate as the oxi dizing agent in gunpowder mixtures. Powders of this character were manufactured and sold, but were unsatisfactory', owing to the deliquescent nature of the ammonium salt. Subsequent to the discovery of guncotton in 1845, experiments were undertaken for the purpose of producing a smokeless powder with that agent, and such pow ders were made by experts in France, Germany, Great Britain. the United States, and especially in Austria, where Von Lenck is credited with having obtained excellent results with guncot ton preparations that were used with field guns in 1867 and 1868. The present employment of smokeless powder may be said to have begun with the invention of poudrc B. in France in ISM. Guttmann divides the smokeless powders into three classes, as follows: (1 1 Powders in which guncotton, either the insoluble or the soluble va riety alone, is used, which, by the aid of a solvent, has been converted into a horny substance and then is formed into flakes or cords; (2) powders in which a mixture of nitroglycerin and either dinitro- or trinitro-eellulose is transformed into a similar horn-like substance, either with or with out the aid of a solvent : and 13) powders that contain nitro-derivatives of the aromatic hydro carbons, either by themselves or in connection with nitro-cellulose. In a general way, the process for manufacturing these powders consists in steeping cellulose in a mixture of nitric and sulphuric acids, and the resulting nitro-cellulose or guncotton is then brought into the colloid condition by treatment with some solvent such as a mixture of alcohol and ether, ethyl acetic ester, or acetone. The solvent chosen depends on the
character of the cellulose nitrate used and the special qualities sought in the product. In cer tain of the smokeless powders oxidizing agents, such as the nitrates of metallic bases, are added to increase the velocity of the explosive, and when the action of the explosive is too violent a deterrent or substance rich in carbon is added. The colloid or ho•n-like substance is then cut into flakes by machines, o• as originally in Italy forced through spaghetti machines, and formed into cords, either solid or perforated, of the de sired dimensions, which are then cut into grains.
Among the various smokeless powders are: Ballintitc, invented by Alfred Nobel in 188S, and made in England; cordite, invented by Sir Fred erick Abel and James Dewar, and made in Eng land; Du Pont powder, invented by F. C. & P. S. Du Pont in 1893, and made in Wilmington, Del.: indnrite, invented by Charles E. -Munroe in 1889. and made at Newport. II. 1.; cibalite, in vented by J. K. von Falkenstein. and made in Germany; poudrc J.. invented by Bruneau, and poudrc pyroxyee, made by the French Govern ment; Tinisdo•f, Von. Forster. Walsrode, and Wetteren. powders, made in Germany, each of which varies slightly from the others in the preparation of the mixture or proportions of the ingredients. For full information on the subject, see the history of the development of smokeless powders given in Charles E. Presi dential address before the Washington Section of the American Chemical Society in 1896. Consult also Longridge, Smokeless Powder and Its In fluence on Gun Construction (London, 1890), and Cuttmann, The Manufacture of Explosives (Lon don. 1895 ) .