Nitro-Naphthalene.—­Nitro-naphthalene is formed by the action of nitric acid on naphthalene (C_{10}H_{8}).  Its formula is C_{10}H_{7}NO_{2}, and it forms yellow needles, melting at 61 deg.  C.; and of di-nitro-naphthalene (C_{10}H_{6}(NO_{2})_{2}), melting point 216 deg.  C. There are also tri-nitro and tetra-nitro and [alpha] and [beta] derivatives of nitro-naphthalene.  It is the di-nitro-naphthalene that is chiefly used in explosives.  It is contained in roburite, securite, romit, Volney’s powder, &c.  Fehven has patented an explosive consisting of 10 parts of nitro-naphthalene mixed with the crude ingredients of gunpowder as follows:—­Nitro-naphthalene, 10 parts; saltpetre, 75 parts; charcoal, 12.5 parts; and sulphur, 12.5 parts.  He states that he obtains a mono-nitro-naphthalene, containing a small proportion of di-nitro-naphthalene, by digesting 1 part of naphthalene, with or without heat, in 4 parts of nitric acid (specific gravity 1.40) for five days.

Quite lately a patent has been taken out for a mixture of nitro-naphthalene or di-nitro-benzene with ammonium nitrate, and consists in using a solvent for one or other or both of the ingredients, effected in a wet state, and then evaporating off the solvent, care being taken not to melt the hydrocarbon.  In this way a more intimate mixture is ensured between the particles of the components, and the explosive thus prepared can be fired by a small detonator, viz., by 0.54 grms. of fulminate.  Favier’s explosive also contains mono-nitro-naphthalene (8.5 parts), together with 91.5 parts of nitrate of ammonia.  This explosive is made in England by the Miners’ Safety Explosive Co.  A variety of roburite contains chloro-nitro-naphthalene.  Romit consists of 100 parts ammonium nitrate and 7 parts potassium chlorate mixed with a solution of 1 part nitro-naphthalene and 2 parts rectified paraffin oil.

Ammonite.—­This explosive was originally made at Vilvorde in Belgium, under the title of the Favier Explosive, consisting of a compressed hollow cylinder composed of 91.5 per cent. of nitrate of ammonia, and 8.5 per cent. of mono-nitro-naphthalene filled inside with loose powder of the same composition.  The cartridges were wrapped in paper saturated with paraffin-wax, and afterwards dipped in hot paraffin to secure their being water-tight.  The Miners’ Safety Explosives Co., when making this explosive at their factory at Stanford-le-Hope, Essex, abandoned after a short trial the above composition, and substituted di-nitro-naphthalene 11.5 per cent. for the mono-nitro-naphthalene, and used thin lead envelopes filled with loose powder slightly pressed in, in place of the compressed cylinders containing loose powder.  The process of manufacture is shortly as follows:—­132-3/4 lbs. of thoroughly dried nitrate of ammonium is placed in a mill pan, heated at the bottom with live steam, and ground for about twenty minutes until it becomes so dry that a slight dust follows the rollers; then 17-1/2