EXPLOSIFS N, O, etc. See under respective letters.
EXTRA DYNAMITE is a variety of American dynamite containing ammonium nitrate.
FAVERSHAM POWDER is a coal-mine explosive of the [Grisounite] type made by the Cotton Powder Co. The mixture, which was on the old Permitted List, had the composition—
| Ammonium nitrate | 90 |
| Trinitro-toluene | 10 |
To make it pass the Rotherham Test, part of the ammonium nitrate was replaced by potassium nitrate, and ammonium chloride was added—
| No. 2. | |
| Date of Permit | 10-2-14 |
| Ammonium nitrate | 47·5 |
| Potassium nitrate | 24 |
| Ammonium chloride | 18·5 |
| Trinitro-toluene | 10 |
Limit charge | 24 oz. |
| Power (swing of ballistic pendulum) | 2·61” |
but this also has now been repealed.
FAVIER explosives consist essentially of ammonium nitrate mixed with nitro-compounds. Favier took out patents in 1884 and 1885 for mixtures of ammonium nitrate with mononitro-naphthalene, paraffin and resin. Their manufacture was undertaken soon afterwards by the French Government, and is still continued under the names of Explosifs N, or Explosifs Favier or Grisounites. Their composition has been varied from time to time, but the following are those now authorised—
Grisou- naphtalite- couche. | Grisou- naphtalite- roche | Grisou- tetrylite- couche. | For mines free from fire-damp, etc. | |||
|---|---|---|---|---|---|---|
| N1a. N4 . | N1b. | N1c. | ||||
| Ammonium nitrate | 95 | 90 | 91·5 | 86·5 | 88 | 87·4 |
| Potassium nitrate | — | 5 | — | 5 | 5 | — |
| Dinitro-naphthane | — | — | 8·5 | 8·5 | — | 12·6 |
| Trinitro-naphthalene | 5 | 5 | — | — | — | — |
| Tetryl | — | — | — | — | 7 | — |
The Grisounites-couche are used in the coal seams as they have theoretical temperatures of explosion of 1500° or less, but N1a has been replaced to a considerable extent by N4, because the presence of a proportion of potassium nitrate is found to increase the safety; these are both coloured green. The Grisounites-roche have theoretical temperatures of explosion of 1900° or less, and are used in the rocks in coal mines. N1b is dyed rose colour, and N1c pale yellow.