1855.] on Gunpowder y aiid its substitutes, 101 



By burning a fuse under water these gases were exhibited. It is. 

 supposed that, at the moment of explosion, the heated gases occupy 

 fully two thousand times the volume of the original powder. By 

 mixing different combustibles with nitre various effects may be 

 produced on explosion ; sometimes the light, sometimes the heat, 

 and sometimes the noise being the most remarkable. When nitre 

 was an article of scarcity in France, the French chemists made 

 many experiments with a mixture of chlorate of potash, charcoal, 

 and sulphur; but this compound, though a good explosive, has 

 several disadvantages, which have prevented its ever coming into 

 extensive use. A white gunpowder has more recently been pre- 

 pared by mixing chlorate of potash with yellow prussiate of potash 

 and sugar. 



Tlie explosives hitherto described are all mixtures. There exist 

 substances which contain all the elements of combustion within 

 themselves, and which require only a slight elevation of temperature, 

 or a smart blow, to alter their state of chemical combination, and 

 suddenly to produce gaseous bodies in large quantity. Pre-eminent 

 among these is Gun-cotton : a substance formed by immersing 

 cotton in a mixture of nitric and sulphuric acids. It is generally 

 allowed now that this compound consists of lignine, C24 Hgo O20, in 

 which a portion of the hydrogen has been replaced by NO4 ; differ- 

 ence of opinion exists as to the amount so displaced, but Dr. Glad- 

 stone had found it to be five atoms in the most explosive gun- 

 cotton, three in that of inferior quality, which he designated cotton- 

 xyloidine. The most explosive compound produces a sudden flash, 

 but no smoke or loud noise, and leaves no residue whatever. Hy- 

 drocyanic acid is among the resulting gases. — Nitroglycerine, a 

 liquid produced in a similar manner from glycerine, is of so explo- 

 sive a nature, that if a single drop be struck by a hammer on an 

 anvil it gives rise to a deafening report. Its composition is Ce H5 3 

 (NO4) Oe* Similar to this is nitromannite, which also explodes on 

 percussion . Several other simple nitric acid substitution products are 

 also capable of explosion ; and so are certain salts of organic acids, 

 which are analogous in their constitution ; for instance, carbazotate 

 of potash. Fulminating mercury and silver are also salts of an 

 organic acid, the fulminic, which contains both oxygen and nitrogen. 

 They explode, as is well known, by percussion, and with extreme 

 violence. There are, however, certain detonating compounds, 

 which contain no oxygen, nor any other supporter of combustion, 

 but which are easily caused to undergo an internal change, and to 

 resolve themselves into gaseous products. The most remarkable of 

 these are certain substitution products of ammonia — the so-called 

 ammoniurets of gold and other noble metals, and the so-called 

 iodide and chloride of nitrogen. The iodide is a black powder, 

 which when dry will explode on the slightest touch of a hard sub- 

 stance, and even sometimes by a sudden concussion of the air near 

 it. Its composition had been examined by the speaker, and found 



