Chapter II: On Gunpowder

Origin of its invention--Roger Bacon’s recipe--Accidental discovery
by a German monk--Gunpowder introduced by the Saracens--Its explosive
and propellant properties--Composition of gunpowder--Nitre its
essence--Properties of sulphur as an ingredient--Proportions and
constituents of French gunpowder--Sulphur not always indispensable--
Chemical principles of its composition--Component parts of different
gunpowders--Source of its explosive force--Explosion at Gateshead--
Variations in strength and quickness of fire--Granulation of sporting
gunpowder and of artillery gunpowder--Importance of suitable
granulation for different firearms--Large grain powder the more
effectual expellant--Fine powder dangerous--Principle of granulation--
Gun-cotton--Imperfect instrument for testing gunpowder--Charcoal--
Operation of making gunpowder described--“Glazing” detrimental--
Utility of granulation--Fine grain powder--Dr. Ure on the projectile
force of gunpowder--Dr. Hutton’s calculations and experiments--Mode
of controlling the destructive force of gunpowder--Experiments to test
the velocity of explosive force of different granulations--The grain
should be proportioned to the length and bore of the gun--Chlorate of
potassa used by the French in making gunpowder--Similar powder
proposed by Mr. Parr, and condemned by Sir William Congreve--Velocity
in projectile force must be gradual--Curious experiment--Operation of
blasting stone, &c., with gunpowder--English sporting gunpowder--
Military and naval gunpowder--Fame of English gunpowder makers 18