GUNPOWDER

A compound of about 78 parts of saltpetre, 12 of charcoal, and 10 of sulphur. The ingredients should all be perfectly pure, separately reduced to powder, thoroughly mixed, moistened, and beaten or j)re ed into a cake; which is a*"terwards broken up, granulated or corned, dried, and polished by attrition. Coarse powder is le carefully and nicely manufactured. The force of the explosion of gunpowder is the consequence of the sudden and abundant production of gaseous matter expanded by the intense heat resulting from the action of the combustibles upon the nitre. The gases evolved are chiefly carbonic oxide,carbonic acid, nitrogen, and svilphurous acid, and their volume probably exceeds two you sand times the bulk of the powder. Count Rumford's experiments show the immense energy of this astonishing agent as a source of mechanical power (Phil. Trans, vol.87.): 28 grains of gunpowder, confined in a cylindrical space which it just filled, tore asunder a piece of iron which would have resisted a strain of 400,000 lbs. applied at no greater mechanical advantage. With regard to the introduction of gunpowder into warlike operations. Dr. Thomson has the following remarks: — The discoverer of this compound, and the person who first thought of applying it to the purposes of war, are imknown. It is certain, however, that it was used in the fourteenth century. From certain archives quoted by Wiegleb, it appears that cannons were employed in Germany before the year 1372. No traces of it can be found in any European author previously to the thirteenth century; but it seems to have been known to the Chinese long before that period. There is reason to believe that cannons were used in the battle of Cre y, which was fought in 1346. They seem even to have been used three years earlier, at the siege of Algesiras; but before this time they must have been known in Germany, as there is a piece of ordnance at Amberg on which is inscribed the year 1303. Roger Bacon, who died in 1292, knew the properties of gunpowder; but it does not follow that he was acquainted with its application to fire-arms. [s. 549]