Page:The New International Encyclopædia 1st ed. v. 07.djvu/422

* EXPLOSIVES. 374 EXPLOSIVES. great explosive violence is explained by the feeble affinities of nitrogen for other elements. Explosive Mixtures of the Nitrates. This class consists of those compounds which are me- chanical mixtures of nitrates with some base, and contain charcoal or other substance yielding carbon, also usually containing sulphur. The nitrates are the source of the oxygen which on explosion combines with the carbon of the char- coal, producing large volumes of gases, so that the mixture when confined will at the time of ex- plosion be accompanied by a violent disrupting action. The typical representative of this class is black gunpowder, for a description of the manu- facture of which, see Gunpowder. The standard composition of gunpowder is potassium nitrate (saltpetre) 75 parts, charcoal 15 parts, and sulphur 10 parts; although these ingredients necessarily vary according to the uses for which the powder is desired; thai is. whether for blast- ing, sporting, or warfare. They must also be combined so that ( 1 I the combustion may be complete and little residue left after explosion; (2) that the powder should not readily absorb or retain moisture; (3) that its explosive properties should not be greater than required; and (4) it should be hard and dense enough to bear trans- portation without disintegrating. Excess of carbon and sulphur prevents perfect combustion and lowers the explosive force, while too great an amount of potassium or sodium chloride in the saltpetre will make the powder hygrometric. Disintegration may be prevented by proper stamping. Good gunpowder should have a den- sity between 1.5 and 1.85. and the most powerful powders are those that are the must dense. Its exploding point ranges from 270° C. for blast- ing-powder, 275° C. for rifle-powder, and 315° C. for the best sporting-powder. Among the more important explosive com- pounds in this class may be mentioned the fol- lowing: Amide powder, consisting of a mixture of ammonium and potassium nitrates with char- coal: azotine, consisting of sodium nitrate 69.04 parts, carbon 15.23 parts, sulphur 11.43 parts, and petroleum, 4.l".i parts; carbo-azotine, con- sisting of potassium nitrate 61.04 parts, ferrous sulphate 13.58 parts, soot 24.(15 parts, and sul- phur 13.58 parts; diorexine, consisting of potas- sium nitrate 50 parts, sodium nitrate 25 parts, sulphur 12 parts, and sawdust from hard wood 1:: parts; johnite, consisting of potassium ni- trate 75 parts, sulphur lo parts, lignite l!i parts, sodium picrate 3 parts, and potassium chlorate 2 pails; petralite, consisting of potas- sium nitrate (i4 parts, impregnated wood or charcoal 30 parts, crude antimony 6 parts: pyrolite, consisting of potassium nitrate 51.50 parts, sodium nitrate Hi parts, sulphur 20 parts, sawdust ]| parts, and charcoal 1.50 parts; and sac or poudre barytiqtie, a mixture of barium nitrate and charcoal with a small [portion of potassium nitrate. Explosive iivn res op the Chlorates. On int of the readiness wild which potassium chlorate lends itself to the production of powerful explosives, ii lias 1 n frequently used by in- I lore explosive miilires. It' will combine with almost any carbonac is material, and ', ill readily explode by friction. The tend eney of sueh mixtures (,, spontaneous ignition, as well a- their sensitr to percussion, has pre- vented their extensive adoption. Among the mix- tures in this class that may be mentioned are the following: Asphaline, consisting of potassium chlorate 54 parts, potassium nitrate and sulphate 4 parts, mixed with bran 42 parts; Ehrhardi powder, consisting of a mixture of tannin, pow- dered nutgalls, or cream of tartar, with potas- sium chlorate; Fontaine powder, consisting of a mixture of potassium chlorate and potassium picrate; Worseley pander, consisting of potas- sium chlorate 6 parts, nutgalls 1 part, and charcoal 1 part, mixed with 72 parts of nitro- glycerin (this may also be classed as a dyna- mite) ; Kelloic safety powder, consisting of spent tan and sawdust saturated with potassium or sodium nitrate and a little potassium chlorate, and then mixed with sulphur; Miehalowosld blast- ing-powder, consisting of potassium chlorate 50 parts, manganese dioxide 5 parts, and finely pul- verized organic matter, as bran, 45 parts; Orien- tal powder, consisting of potassium nitrate and crude gamboge mixed with potassium chlorate; pyronome, consisting of potassium nitrate 69 parts, sulphur 9 parts, charcoal 10 parts, metal- lic antimony 8 parts, potassium chlorate 5 parts, rye flour 4 parts, and a small quantity of potas- sium chromate; rackarock, consisting of potas- sium chlorate 79 parts, and mono-nitrobenzine 21 parts, which are prepared separately and com- bined only when about to be used; tutonite, con- sisting of potassium chlorate mixed with sulphur and metallic sulphides; and white powder, con- sisting of a mixture of sugar, potassium ferro- cyanide, and potassium chlorate. Explosive Compounds Derived by Nitro-Sub- stitution. This class consists of a series of compounds that are formed by treating certain hydrocarbons of the aromatic series, which are for the most part coal-tar products, with nitric acid; producing a new chemical compound which is relatively unstable, and contains elements that are capable of uniting at a high temperature to form stable gases. These explosives accomplish their purpose by a dissociation of the constituent elements of the compound, which then recombine into a variety of gaseous compounds. These ex- plosives are sometimes called 'safety explosives.' and have considerable economic value, especially for blasting purposes, largely owing to the fact that they do not give off fume's of poisonous gases, and have a high rending or expansive ' forei. A Qg representative members of this class may be mentioned the following: Ammonites or Fa- vier explosives, consisting „f ammonium nitrate 88 parts, mixed into 12 parts of melted di nitro- naplitlialcne ; bellite, consisting of ammonium nitrate 5 parts, and meta-di-nitrobenzine 1 part. melted together, and potassium nitrate stirred into the mixture: Borlinetto powder, consisting "'' picric acid 10 parts, sodium nitrate 10 parts, and potassium chromate 8% parts; extralite, consisting of a mixture of ammonium nit rate, potassium chlorate, and naphthalene: joveite, consisting of varying proportions of nitro-naph- thalene (8 to i; parts), nitro-phenol (16 to 30 parts), and sodium nitrate (76 to 01 parts); roburite, consisting of a mixture of ammonium nitrate ami well purified chlorinate, I di-nitro- benzine; romite, consisting of a mixture of am- monium nitrate, potassium chlorate, and naph- thalene; securite, consisting of a mixture of am- monium nitrate and di nil rol.eiizino ; and Volney powder, consisting of potassium nitrate, sulphur,.