Mr. Hallam, referring to the authority of an Arabic author, infers that there is no question that the knowledge of gunpowder was introduced into Europe through the means of the Saracens, before the middle of the 13th century; and no doubt its use then was more for fireworks, than as an artillerist projectile force. There is good evidence, too, that the use of gunpowder was introduced into Spain by the Moors, at least as early as the year 1343. Now, as Roger Bacon is known to have been an Arabic scholar, it is not at all unlikely that he might have become acquainted with the mode of making the composition, and also with its most remarkable properties, by perusing some Arabian writer with whom we are at present unacquainted.
This invention, by which the personal barbarity of war has certainly been diminished, is, when considered as a means of human destruction, by far the most powerful that skill has ever devised, or accident presented; acquiring, as experience shows us, a more sanguinary dominion in every succeeding age, and subserving all the progressive resources of science and civilization for the extermination of mankind: which, says Mr. Hallam, “appals us at the future prospects of the species, and makes us feel, perhaps, more than in any other instance, a difficulty in reconciling the mysterious dispensation with the benevolent order of Providence.”
The composition of gunpowder, as regards the proportions of the ingredients, has not undergone any material alteration; the chemical proportions of the ancients being nearly those of the present day.
Gunpowder is an explosive propellant compound, consisting of saltpetre or nitre, charcoal, and sulphur. The terms, explosive and propellant, are not here used as synonymous—they are not convertible; for a chemical mixture may possess the explosive power in a much higher degree than the propellant: fulminating gold, silver, and mercury, are dreadfully explosive; but they have not the same projectile force, nor can they be used as a substitute for it. Several experiments have been made with compounds of this nature, but the result is the reverse of what might be expected. Nothing can resist the exceeding intensity of the action of fulminating powder; a shot, when fired in this way, is not projected as by gunpowder, but is split into fragments by the velocity of its explosion, as we shall hereafter have occasion to show.
Nitre, or saltpetre, is strictly the essence of gunpowder. It is a triple compound of oxygen, nitrogen, and potassium. The chemical action of those elements on each other, and the play of affinities between them at a high temperature, occasion the immense effect produced by gunpowder on the application of fire or heat. By universal consent, sulphur is included in the mixture, but it is not absolutely necessary for the “propellant power;” for nitre and charcoal only will generate effects similar to the compound with sulphur. Gunpowder made without sulphur has, however, several bad qualities; it is not, on the whole, so powerful, nor so regular in its action; it is also porous and friable, possessing neither firmness nor solidity. It cannot bear the friction of carriage, and in transport crumbles into dust. The use of sulphur, therefore, appears to be not only to complete the mechanical combination of the other ingredients, but being a perfectly combustible substance, it increases the general effect, augments the propellant power, and is thought to render the powder less susceptible of injury from atmospheric influence.
“There is one good reason,” says the Edinburgh Encyclopædia, “for the use of sulphur, although it does not contribute to the production of any elastic fluid. The carbonic acid which is generated would doubtless combine with the potash, if it were not for the presence of the sulphur, and thus so much elastic fluid would be lost. That this is the case we know to be true, from the fact that carbonate of potash is always formed when nitre is decomposed by charcoal alone, which I shall almost immediately show.” This certainly would be the case, to a certain extent, with gunpowder without sulphur—some carbonate of potash would be formed.
The sulphur, we have no doubt, from experiments we have made on this subject, is, in part, engaged during the explosion of gunpowder in expelling the sixth proportion of oxygen from the potash, so as to combine with the potassium, to form a true sulphuret of that metal. This fact is easily ascertained, from the circumstance that no sulphuretted hydrogen can be detected, by the most delicate tests, coming from the residuum left after firing gunpowder, until moisture has gained access to it. The bad smell which arises sometime after the burning of gunpowder, is occasioned by the decomposition of the moisture which the sulphuret of potassium attracts from the atmosphere; giving rise, by this decomposition and liberation, to the fœtid foul gas, called sulphuretted hydrogen, and the production of potassa, or the oxide of potassium.
A commission of French chemists and artillerists was appointed by the Government, in the year 1794, to experiment upon the best proportions and constituents of gunpowder for the use of the French service. The following were the proportions of five different kinds prepared at the Essonne works:—
| No. | Nitre. | Charcoal. | Sulphur. | —— | |
|---|---|---|---|---|---|
| 1 | 76·00 | 14·00 | 10·00 | Powder of | Bâe. |
| 2 | 76·00 | 12·00 | 12·00 | „ | Grenelle. |
| 3 | 76·00 | 15·00 | 9·00 | „ | M. Morveau. |
| 4 | 77·32 | 13·44 | 9·24 | „ | Ditto. |
| 5 | 77·50 | 15·00 | 7·50 | „ | M. Keffault. |