II

OF GUN-POWDER.

only of the mixture in contact with the coal will burn, theflame not being able to communicate itself to the other parts.If, on the, contrary, the nitre be in too small a quantity, onapplying fire to one part, the flame which breaks out at itsdecomposition is too weak to spread itself to the others,owing to the great distance of the nitrous particles : the de-struction of the whole, therefore, requires a much longertime; and the quantity of permanent elastic fluid, onwhich depends the greatest force of the powder, is less; asmay be proved b ■ burning a mixture of equal parts of sul-phur, charcoal, and saltpetre.

38. That proportion which will most readily produce thedestruction of all the composition, and yield the greatest possiblequantity of the permanent elastic fluid in a given time, oughtto be found out, and will constitute powder of the best qua-lity : it evidently appears, from the above experiments, to liebetween the quantities there made use of.

39. In the first years that succeeded to the discovery ofgun-powder in Europe, the proportion of the constituentparts, and the size of the grains, varied very much ; whichgave rife to the several denominations it has obtained. Atthe beginning of this century, these proportions and sizeswere almost every where reduced to three; and at present,throughout all Europe, only one kind is used for military pur-poses.

As it will be shewn in this treatise that the properties ofpowder are modified by the qualities of the ingredients andthe size of the grains, to save repeated descriptions of thedifferent kinds of powder that may come under our investi-gation, we will subjoin a general account of them, accordingto the various denominations that they are commonly knownby; with this observation, that whatever may be advancedconcerning the modifications of one kind of powder is appli-cable to all others.

40. Powder composed of 5 parts of saltpetre, 1 of char-coal, and 1 of sulphur, and granulated so as to enter withease into the vents of new musquets, is called enusquet pow-der ; when the grains are three or four times larger, it iscalled cannon powder. Powder composed of 6 parts of salt-petre, 1 of charcoal, and 1 of sulphur, the grains of whichare of the fame size as musquet powder, is called common warpowder ; and obtains' the name of fine war powder when thegrains are about half that size. Powder made with the same

proportion.