Gun-powder being a principal ingredient in fireworks, it will not be improper to give a short definition of its strange explosive force, and cause of action, which, according to Dr. Shaw’s opinion, of the chemical cause of the explosive force of gun-powder, is as follows. “Each grain of powder consisting of a certain proportion of sulphur, nitre, and coal, the coal presently takes fire, upon contact of the smallest spark: at which time both the sulphur and the nitre immediately melt, and by means of the coal interposed between them, burst into flame; which spreading from grain to grain, propagates the same effect almost instantaneously: whence the whole mass of powder comes to be fired; and as nitre contains both a large proportion of air and water, which are now violently rarified by the heat, a kind of fiery explosive blast is thus produced, wherein the nitre seems, by its aqueous and aërial parts, to act as bellows to the other inflammable bodies, sulphur and coal, to blow them into a flame, and carry off their whole substance in smoke and vapour.” After having spoke of the nature of powder, I shall in the next place proceed to its original, though somewhat uncertain; but it is imagined to have been invented in the time of Alexander the great, as Philostratus speaks of a city near the river Hypasis in the Indies, that was said to be impregnable and its inhabitants relations of the gods, because they thew thunder and lightning on their enemies; but this perhaps might be the effect of gun-powder, which, not being known by any other people, might very well be said to be thunder and lightning. This conjecture has been confirmed by some travellers, who assert that it was used in the East Indies, particularly in the Philippine Islands about the year 85, which is 1265 years before it was known in Europe, where they say it was not known till 1350, though, it is said, there is mention made of gunpowder in the registers of the chambers of accounts in France, as early as the year 1338, and Friar Bacon mentions the composition of powder in express terms, in his treatise De nullitate magiae, published at Oxford in the year 1216; but we find from most accounts, that the Germans have the honour of the invention, as is commonly reported. I should give a description of a machine for the trying of gun powder, but they being so common, it would be needless; yet, would have all those who practice this art, know, that, when they make sky rockets with powder, that it must be of the best sort; but as to wheels, and other common works, any powder will do, only be careful that it is quite dry. Of the Compositions for GUN-POWDER of different sorts.