"The goodness of the powder depends on the excellence of the charcoal; and there is but one mode of obtaining this in perfection, which is distillation in close vessels, as practised by the English.
"The charcoal of our powder manufactories is at present prepared in pots, where the wood receives the immediate action of the air, which occasions the charcoal to undergo a particular alteration."
In 1724, (Coll. Academ. t. v, p. 413,) M. de Moraler proposed a new mode of mixing the materials for gunpowder. In 1759, M. Musy proposed another method to prevent explosions; and in 1783, the baron de Gumprecht constructed a very ingenious powder mill, a model of which he presented to the king of Poland, whose approbation it received.
There is an account in detail, of the results of the experiments made by MM. Regnier and Pajot Laforet, with different fulminating powders, in the Archives des Découvertes, iii, p. 337. These experiments, although interesting in a philosophical view, cannot be of service in the present case. They were made with gunpowder, fulminating silver, fulminating silver and mercury combined, fulminating mercury alone, &c. See also the Bulletin de la Société d'Encouragement, cahir 65.
The observations of M. Proust (Journal de Physique for May, 1815) on the mixing of powder, and the consequences that result by following the old process, may be consulted.
The process of manufacturing gunpowder, which we have described, is followed in all, or the greater part of the factories of France. It is, however, tedious, and not exempt from danger. The same process, with some modifications or improvements, is adopted in this country; but of all our gunpowder manufactories, that of the messrs. Dupont of Brandywine, Delaware, has heretofore produced the best powder. Powder, however, equally powerful, has been made in other factories.
The improved process of M. Champy, which, in many respects, is superior to the foregoing, is the following:
1. The nitre, sulphur, and charcoal are first reduced, separately, to very fine powder. This operation is performed in barrels, which are made to turn upon their axis, similar to the barrel-churn, and the substances are introduced gradually. Balls, made of an alloy of copper and tin, are then put in, which by their action reduce the substances to powder.
2. The second operation has for its object, the intimate mixture of the ingredients. The quantities to be mixed are weighed, and put into a drum with a quantity of shot, which is made to revolve during an hour and a quarter. In this manner, three hundred pounds of the mixture are at once operated upon.
3. The mixture is then moistened with water. About fourteen per cent. is added. It is then passed through a sieve made with round holes, and then put into a drum, and submitted for a half hour, to a rotary motion. A number of small round grains are thereby formed, which are separated from the mass by means of a sieve, the holes of which are very small.