Page:The New International Encyclopædia 1st ed. v. 07.djvu/423

* EXPLOSIVES. 375 EXPLOSIVES. and nitro-naphthalene. .Many ..l these explosives pass into the Sprengel class. Explosive Compounds of the Nitbic Debiva- TIVES. This group of explosives consists of nitric derivatives either of cellulose or gelatin. In the first case the cellulose is treated with nitric acid, forming guncotton, and in the 9< nd case glycerin yields. 1 1- the action of nitric acid, nitroglycerin. According to the proportions used the mono-, di-, or tri-nitro derivatives of glycerin or a multiple of them for cellulose may be obtained. This class is by far the largest one, and too numerous to admit of a general de- scj'i |il iim. in consci|iiencc of which 1 he peculiar properties of each will be found described under their special headings. Quncotton is an important member of this class. Jt consists of cellulose such as pure cot- ton treated with nitric acid, although in actual practice the best results are obtained from a. mix- ture of nitric acid and sulphuric acid. It is em- ployed chiefly for military purposes and is re- garded as I he safest explosive known. (See 111 X cotton. ) Among the various guncotton prepara- tions, which differ from each other only by the proportions of their ingredients and methods of preparation, are the following, which are now seldom used, although valuable on account of their safety: Qlyoscilme, a guncotton pulp which is mixed with potassium nitrate, converted into porous pellets which are saturated with nitro- glycerin and afterwards coated with varnish to protect them from moisture: potentite, a mixture of 02.2 parts guncotton and 33.8 parts potassium nitrate compressed into cartridges; tonite or cotton powder, a preparation consisting of 52.5 parts of finely divided or macerated guncotton with 47.5 parts of barium nitrate, which are made up into cartridges coated with paraffined pa per. The value of guncotton as an explosive led to its adoption for use in the manufacture of blasting-gelatin, invented by Nobel in 1875. which is accomplished by dissolving the soluble variety of guncotton in nitroglycerin. This has been made up variously, and also combined with absorbents, forming gelatin dynamites, which have been largely used for blasting purposes, notably in the ease of the Saint Gotthard tunnel. In this class should be included forcite, consist- ing of blasting-gelatin (nitroglycerin 98 parts, collodion cotton 2 parts), 50 parts, and absorb- ent (sodium nitrate 70 parts, sulphur 3 parts, wood tar 20 parts, wood pulp 1 part), 50 parts; and gelignite, consisting of blasting-gelatin (ni- troglycerin 96 parts, collodion cotton 4 parts) 65 parts, and absorbent (sodium nitrate 75 parts, sodium carbonate 1 part, wood pulp 24 parts), 35 parts. Smokeless Powders represent, the latest de- velopment of explosives containing guncotton, and consist chiefly of either a guncotton which, by the aid of a solvent, has been converted into a colloid mass which, when dried, is a hard horn- like material, which may then be formed into flakes or cords, or of a powder in which a mix- ture of guncotton and nitroglycerin is trans- formed into a similar horn like substance either with or without the aid of a solvent. In the first class are the Bernadou powder, consisting of a nitrocellulose brought into the colloid con- dition by treating with ether-alcohol and acetone; poudre B of Vieille, used in France, and con- sisting of guncotton mixed with barium nitrate, potassium mi rate, and sodium carbonate, and treated with either ether-alcohol, ethyl acetate, or acetone; and Wetteren powder, used in Ger- many, and consisting of nitro-cotton 48.15 pari , guncotton 30.73 parts, charcoal 12.12 parts, vola- tile matter 8.22 parts, and humus o.77 part, The foregoing are typical of the military smoke- less powders. Sporting powders of similar char- acter are now made, in which the process of manufacture and the proportions of the ingredi- ents are changed to produce the desired results. Of the second class, the most, important, are: Amberite, consisting of tri-nitrocellulose 44 parts, di-nitrocellulose 12 parts, and nitroglycerin 40 parts, formed into grains and treated with sol- vent, consisting of sulphuric ether with a little alcohol; ballistite, consisting of guncotton 40 parts, dissolved in nitroglycerin 60 parts, to which a small quantity of aniline has been added as a neutralizing agent ; cordite, consisting of nitroglycerin 58 parts, guncotton 37 parts, vase- line 5 parts, dissolved in 19.2 parts of acetone; filite is similar to ballistite and is used in Italy for military purposes. Certain varieties of smokeless powders consist of nitrocellulose com- bined with nitro-derivatives of aromatic hydro- carbons, and included in this class are itn Pont powder, consisting of nitrocellulose brought into the colloid condition by nitro-benzine or other soluble solvent; and indurite, produced by treat ing highly nitrated cellulose with mono-nitro- benzine until it is brought into the colloid condi- tion and then removing the collodizing agent. Both of the last-named powders are of American origin, and differ from each other in the method of manufacture and proportion of ingredients. See Smokeless Powders. Nitroglycerin. This most powerful explosive was discovered by Ascanio Sobrero, in Turin, Italy, 1847, and is a colorless or light yellow oily liquid made by passing pure glycerin into a mixture of concentrated nitric acid and sul- phuric acid which explodes violently at 180° C. Its tendency to decompose, resulting in violent explosion, has led to the abandonment of it as an explosive, but when combined with a suitable absorbent, this property is removed, and has given rise to a very important series of explosives known genericallv as dynamites, which may be again subdivided into two principal groups, namely, dynamites with an inert absorbent and dynamites with an active absorbent. The type of the first group is the original dynamite in- vented by Nobel in 1866, who used for his absorb- ent diatomaceous silica, siliceous marl, tripoli, or rotten-stone, commonly called kieselguhr. It is made of various degrees of strength, rang- ing from nitroglycerin 75 parts and absorbent 25 parts, down to nitroglycerin 30 parts and ab- sorbent 70 parts. Other explosives of this class are carbodynamite, consisting of nitroglycerin 90 parts and charcoal made from cork 10 parts. and cerberite, consisting of nitroglycerin modi- fied with wood tar and nitro-benzine with charcoal as an absorbent. The second group com- prises those dynamites that are composed of nitroglycerin and an active absorbent, usually a nitrate mixture. The following are among the more important commercial dynamites of this group, the ingredients of which vary in amount according to the special purpose for which they are intended, so that the proportions mentioned