| Ammonium perchlorate | 60 |
| Sodium nitrate | 23 |
| Dinitro-toluene | 11 |
| Paraffin wax | 6 |
As the sodium nitrate in the above is not equivalent to the ammonium perchlorate, part of the chlorine is given off in the form of the poisonous gas, hydrogen chloride (hydrochloric acid).
BLASTING GELATINE.—Nitroglycerine, stiffened by having collodion cotton dissolved in it. Discovered by Nobel in 1875. It contains about—
| Nitroglycerine | 93 |
| Collodion cotton | 7 |
and also often a fraction of a percentage of calcium or magnesium carbonate to increase its stability. This is the most powerful of all the explosives in common use.
BOBBINITE.—The only explosive of the gunpowder class the use of which is permitted in coal mines in England. In most foreign countries explosives of this class are not allowed to be used in them at all. The permission is only temporary, but has been extended to the end of 1920, and is restricted to mines that are not gassy or dangerous from coal dust. There are two definitions, but the second is the one that is generally manufactured apparently—
| First. | Second. | |
| Potassium nitrate | 63·5 | 65 |
| Charcoal | 18·5 | 20 |
| Sulphur | 2 | 2 |
| Sulphates of ammonium and copper | 15 | — |
| Rice or maize starch | — | 9 |
| Paraffin wax | — | 3 |
| Moisture | 1 | 1 |
More than a million pounds of this explosive are used in coal mines every year. It shatters the coal less than high explosives do.
BOMLIT.—A German potassium perchlorate blasting explosive made by Wolff et Cie. at Walsrode. It contains also ammonium nitrate, trinitro-toluene and guncotton. Other ingredients that may be present are potassium and sodium nitrates, starch meal, vaseline, naphthalene and other hydrocarbons, charcoal and castor oil.
BRITONITE.—A coal-mine explosive of the [Carbonite] type, made by the British Explosives Syndicate, Ltd., Pitsea. The original composition passed the Woolwich Test and was on the list of Permitted Explosives, but on the introduction of the Rotherham Test it became necessary to add ammonium oxalate or sodium chloride. Nos. 2 and 3 were on the Permitted List, but have now been repealed.