as we have observed in the Encyclopaedia under the word Gun, has been known in the east, and particularly in China, from a period of very remote antiquity. No man, however, seems to have suspected that the knowledge of it was conveyed from the east into Europe; but all have agreed to allow the merits Gunpowder merits of the invention both to friar Bacon and to Bartholomew Schwartz. This generally received opinion has been lately controverted by citizen Langley, who, in a memoir read in the French national institute, contends, that the knowledge of gunpowder was conveyed to us from the Arabs, on the return of the Crusaders to Europe. He affirms us that the Arabs made use of it in 690 at the siege of Mecca; and he adds, that they derived it from the Indians, among whom it must have been known in the remotest ages, since their sacred books (the Vedam) forbid the use of it in war.

It is indeed extremely probable, that the composition of gunpowder was known in India at a very early period; for in whatever country nature forms nitre in the greatest plenty, there its deflagrating quality is most likely to be first observed; and a few experiments founded on that observation, will lead to the composition which produces such sudden and violent effects.

"Nitre (says Sir George Staunton) is the natural and daily produce of China and India; and there, accordingly, the knowledge of gunpowder seems to be coeval with that of the most distant historic events. Among the Chinese, it has been applied at all times to useful purposes; such as blasting rocks, and removing great obstructions, and to those of amusement in making a vast variety of fire-works. It was also used as a defence, by undermining the probable passage of the enemy, and blowing him up. But its force had not been directed through strong metallic tubes as it was by Europeans soon after they had discovered it. And though, in imitation of Europe, it has been introduced into the armies of the East, other modes of warfare are sometimes still preferred to it."

Of gunpowder manufactured by those who have manufactured it so long, it is desirable to know the composition and the qualities. It was therefore natural for the Hon. George Napier, when superintending the royal laboratory at Woolwich, and making experiments upon to necessary an implement of modern war, to procure some Chinese powder from Canton.

This he did; and analyzing two ounces of it, he found, after repeating the operation five times, that the mean result gave the following proportions*: Nitre 1 oz. 10 dwts. charcoal 6 dwts. sulphur 3 dwts. 14 grs. Here is a deficiency in weight of ten grains, which Mr. Napier supposes the consequence of some defect in his process; but as M. Baume, a French chemist, made a variety of experiments to obtain a total separation of the sulphur from the charcoal of gunpowder, and was never able to effect it, one fourteenth part remaining united, three grains must be deducted from the charcoal, and added to the sulphur to give the accurate proportion of the ingredients; which by turning to the article Gunpowder, Encycl. the reader will perceive differs somewhat from the proportion of the same ingredients in the gunpowder of Europe. This Chinese powder was usually large-grained, and not strong, but very durable. It had been made many years when our author got it; yet there was no visible symptom of decay, the grain being hard, well coloured, and though angular, it was even-sized, and in perfect preservation.

When we consider the operations in which gunpowder is employed, it is obvious that it must be an object of importance to ascertain its explosive force; and yet there is scarcely a subject concerning which the most approved writers have so much differed. Mr. Robins, who has done more towards perfecting the art of gunnery than any other individual, states the explosive force of gunpowder to be 1000 times greater than the mean pressure of the atmosphere; while the celebrated Daniel Bernoulli determines it to be not less than 10,000 times this pressure. Such a difference of opinion led Count Rumford to pursue a course of experiments, of which some were published in the Transactions of the Royal Society for the year 1781, and the remainder in the Transactions of the same Society for 1797; with the view principally of determining the initial expansive force of gunpowder. By one of these experiments, it appeared that, calculating even on Mr. Robins's own principles, the force of gunpowder, instead of being 1000 times, must at least be 1308 times greater than the mean pressure of the atmosphere. From this experiment, the Count thought himself warranted in concluding, that the principles affirmed by Mr. Robins were erroneous, and that his mode of ascertaining the force of gunpowder could never satisfactorily determine it. Depriving of success in that way, he resolved to make an attempt for ascertaining this force by actual measurement; and after many unsuccessful experiments, he was at length led to conclude, that this force was at least 50,000 times greater than the mean pressure of the atmosphere.

Mr. Robins apprehends that the force of fired gunpowder consists in the action of a permanently elastic fluid, similar in many respects to common atmospheric air; and this opinion has been very generally received; but Count Rumford thinks, that though the permanently elastic fluids, generated in the combustion of gunpowder, assist in producing the effects which result from its explosion, its enormous force, allowing it to be 50,000 times greater than the mean pressure of the atmosphere, cannot be explained, without supposing that it arises principally from the elasticity of the aqueous vapour generated from the powder in its combustion.

"The brilliant discoveries of modern chemists (says he) have taught us, that both the constituent parts of which water is composed, and even water itself, exist in the materials which are combined to make gunpowder; and there is much reason to believe that water is actually formed, as well as ditengaged, in its combustion. M. Lavoisier, I know, imagined that the force of fired gunpowder depends in a great measure upon the expansive force of uncombined caloric, supposed to be let loose in great abundance during the combustion or deflagration of the powder: but it is not only dangerous to admit the action of an agent whose existence is not yet clearly demonstrated; but it appears to me that this supposition is quite unnecessary, the elastic force of the heated aqueous vapour, whose existence can hardly be doubted, being quite sufficient to account for all the phenomena. It is well known that the elasticity of aqueous vapour is incomparably more augmented by any given augmentation of temperature than that of any permanently elastic fluid whatever; and those who are acquainted with the amazing force of steam, when heated only to a few degrees above the boiling point, can easily perceive that its elasticity must be almost infinite when greatly condensed and heated to the temperature... known strength of iron, and the area of the fracture of gunpowder.

the barrel in the preceding experiment; of the real force employed by the elastic vapour to burst it; and he computes that it must have been equal to the pressure of a weight of 412529 lbs.; which, by another computation, he found to be 55004 times greater than the mean pressure of the atmosphere. By another process, he investigates the strength of the iron of which the barrel was made; and he thence finds that the force required to burst it was equal to the pressure of a weight of 416644 lbs. This weight, reduced into atmospheres, gives 54750 atmospheres for the measure of the force exerted by the elastic fluid in the present instance. This force must be considerably less than the initial force of the elastic fluid generated in the combustion of gunpowder, before it has begun to expand; "for it is more than probable (says Count Rumford) that the barrel was in fact burst before the generated elastic fluid had exerted all its force, or that this fluid would have been able to have burst a barrel still stronger than that used in the experiment."

After having shewn the extreme force of fired gunpowder, the Count adverts to an objection which may be made against his deductions. How does it happen that firearms and artillery of all kinds, which certainly are not calculated to withstand so enormous a force, are not always burst when they are used? Instead of answering this question, by asking how it happened that the extremely strong barrel used in his experiment could be burst by the force of gunpowder, if this force be not in fact much greater than it has ever been supposed to be, he proceeds to shew that the combustion of gunpowder, instead of being instantaneous, as Mr Robins's theory supposes, is much less rapid than has hitherto been apprehended; an observation, which, if established, is certainly sufficient to answer the objection.

He remarks, that it is a well-known fact, that on the discharge of firearms of all kinds there is always a considerable quantity of unconsumed grains of gunpowder blown out of them; and what is very remarkable, as it leads directly to a discovery of the cause of this effect, these unconsumed grains are not merely blown out of the muzzles of firearms, but come out also by their vents or touch-holes, where the fire enters to inflame the charge, as many persons who have had the misfortune to stand with their faces near the touch-hole of a musket, when it has been discharged, have found to their cost.

It appears extremely improbable to our author, if not absolutely impossible, that a grain of gunpowder actually in the chamber of the piece, and completely surrounded by flame, should, by the action of that very flame, be blown out of it without being at the same time set on fire. And, if this be true, he considers it as a most decisive proof, not only that the combustion of gunpowder is less rapid than it has generally been thought to be, but that a grain of gunpowder actually on fire, and burning with the utmost violence over the whole of its surface, may be projected with such a velocity into a cold atmosphere, as to extinguish the fire, and suffer the remains of the grain to fall to the ground unchanged, and as inflammable as before.

This extraordinary fact was ascertained beyond all possibility of doubt by the Count's experiments. Having procured from a powdermill in the neighbourhood... of the city of Munich a quantity of gunpowder, all of the same mass, but formed into grains of very different sizes, force as small as the grains of the finest Battel powder, he placed a number of vertical screens of very thin paper, one behind another, at the distance of 12 inches from each other; and loading a common musk- et repeatedly with this powder, sometimes without and sometimes with a wad, he fired it against the fore- most screen, and observed the quantity and effects of the unconfined grains of powder which impinged ag- ainst it. The screens were so contrived, by means of double frames united by hinges, that the paper could be changed with very little trouble, and it was actually changed after every experiment.

The distance from the muzzle of the gun to the first screen was not always the same; in some of the expe- riments it was only 8 feet, in others it was 10, and in some 12 feet.

The charge of powder was varied in a great number of different ways; but the most interesting experiments were made with one single large grain of powder, pro- pelled by smaller and larger charges of very fine grained powder.

These large grains never failed to reach the screen; and though they sometimes appeared to have been bro- ken into several pieces by the force of the explosion, yet they frequently reached the screen entire; and sometimes passed through all the screens (five in num- ber) without being broken.

When they were propelled by large charges, and consequently with great velocity, they were seldom on fire when they arrived at the first screen; which was evi- dent, not only from their not setting fire to the paper (which they sometimes did), but also from their being found sticking in a soft board, against which they struck, after having passed through all the five screens; or leaving visible marks of their having been impinged against it, and being broken to pieces and dispersed by the blow. These pieces were often found lying on the ground; and from their forms and dimensions, as well as from other appearances, it was often quite evident that the little globe of powder had been on fire, and that its diameter had been diminished by the combus- tion before the fire was put out, on the globe being projected into the cold atmosphere.

That these globes or large grains of powder were al- ways set on fire by the combustion of the charge, can hardly be doubted. This certainly happened in many of the experiments; for they arrived at the screens on fire, and set fire to the paper; and in the experi- ments in which they were projected with small ve- locities, they were often seen to pass through the air on fire; and when this was the case, no vestige was to be found. They sometimes passed on fire through several of the foremost screens without setting them on fire, and set fire to one or more of the hind- most, and then went on and impinged against the board, which was placed at the distance of 12 inches behind the last screen.

The Count then proceeds to mention another expe- riment, in which the progressive combustion of gunpow- der was shown in a manner still more striking and not less conclusive.

A small piece of red-hot iron being dropped down into the chamber of a common horse pistol, and the pistol being elevated to an angle of about 45 degrees, upon dropping down into its barrel one of the small globes of powder (of the size of a pea), it took fire, and was projected into the atmosphere by the elastic fluid generated in its own combustion, leaving a very beautiful train of light behind it, and disappearing all at once like a falling star. This amusing experiment was repeated very often, and with globes of different sizes. When very small ones were used singly, they were commonly consumed entirely before they came out of the barrel of the pistol; but when several of them were used together, some, if not all of them, were commonly projected into the atmosphere on fire.

As the slowness of the combustion of gunpowder is undoubtedly the cause which has prevented its enor- mous and almost incredible force from being discov- ered, our author deduces, as an evident consequence, that the readiest way to increase its effects, is to contrive matters so as to accelerate its inflammation and com- bustion. This may be done in various ways; but, in his opinion, the most simple and most effectual man- ner of doing it would be to set fire to the charge of powder, by shooting (through a small opening) the flame of a smaller charge into the midst of it.

He contrived an instrument on this principle for firing cannon three or four years ago; and it was found, on repeated trials, to be useful, convenient in practice, and not liable to accidents. It likewise supercedes the necessity of using priming, of vent tubes, port-fires, and matches; and on that account he imagined it might be of use in the British navy, but it does not appear to have been received into practice.

Another infallible method of increasing very con- siderably the effect of gunpowder in fire arms of all forts and dimensions, would be to cause the bullet to fit the bore exactly, or without windage, in that part of the bore at least where the bullet rests on the charge; for, when the bullet does not completely close the op- ening of the chamber, not only much of the elastic fluid, generated in the first moment of the combustion of the charge, escapes by the side of the bullet; but what is of still greater importance, a considerable part of the unconfined powder is blown out of the cham- ber along with it in a state of actual combustion, and, getting before the bullet, continues to burn on as it passes through the whole length of the bore; by which the motion of the bullet is much impeded.

The loss of force which arises from this cause, is in some cases almost incredible; and it is by no means dif- ficult to contrive matters so as to render it very appar- ent, and also to prevent it.

If a common horse-pistol be fired with a loose ball, and so small a charge of powder that the ball shall not be able to penetrate a deal board so deep as to stick in it when fired against it from the distance of six feet; the same ball, discharged from the same pistol with the same charge of powder, may be made to pass quite through one deal board, and bury itself in a second placed behind it, merely by preventing the loss of force which arises from what is called windage, as he found more than once by actual experiment.

The Count has in his possession a musket, from which, with a common charge of powder, he fires two bullets at once with the same velocity that a single bul- let is discharged from a musket on the common con- struction with the same quantity of powder. And, what renders the experiment still more striking, the diameter of the bore of his musket is exactly the same as that of a common musket, except only in that part of it where it joins the chamber; in which part it is just so much contracted, that the bullet, which is next to the powder, may stick fast in it. He adds, that though the bullets are of the common size, and consequently considerably less in diameter than the bore, means are used which effectually prevent the loss of force by windage; and to this last circumstance, he concludes, it is doubtless owing, in a great measure, that the charge appears to exert so great a force in propelling the bullets.

That the conical form of the lower part of the bore where it unites with the chamber has a considerable share in producing this extraordinary effect, is, however, very certain, as he has found by experiments made with a view merely to ascertain that fact.

At the close of the Count's last memoir, we have a computation, designed to show that the force of the elastic fluid generated in the combustion of gunpowder, enormous as it is, may be satisfactorily explained on the supposition that it depends solely on the elasticity of watery vapour, or steam. From experiments made in France in the year 1790, it appears that the elasticity of steam is doubled by every addition of temperature equal to 30° of Fahrenheit's thermometer. As the heat generated in the combustion of gunpowder cannot be less than that of red-hot iron, it may be supposed equal to 1000° of Fahrenheit's scale—but the elastic force of steam is just equal to the mean pressure of the atmosphere, when its temperature is equal to that of boiling water, or to 212° of Fahrenheit's thermometer; consequently $212^\circ + 30^\circ = 242^\circ$ will represent the temperature, when its elasticity will be equal to the pressure of two atmospheres; and, pursuing the calculation, at 602°, or 2° above the heat of boiling linseed oil, its elasticity will be equal to the pressure of 8192 atmospheres, or above eight times greater than the utmost force of the fluid generated in the combustion of gunpowder, according to Mr. Robin's computation: but the heat in this case is much greater than that of 602° of Fahrenheit; and therefore the elasticity of the steam generated from the water contained in the powder must be much greater than the pressure of 8192 atmospheres. At 722°, the elasticity will be equal to the pressure of 131,072 atmospheres; and this temperature is less than the heat of iron, which is visibly red-hot in daylight, by 35°—but the flame of gunpowder has been found to melt brass, which requires a heat equal to that of 2807° of Fahrenheit; 27° above the heat of red-hot iron, or 305° higher than the temperature which gives to steam an elasticity equal to the pressure of 131,072 atmospheres. That there is in gunpowder water sufficient for supplying the necessary quantity of steam, the author has very satisfactorily evinced: but we must not pursue his curious investigations any farther. Those who want a fuller account of them, will find it either in the original memoirs themselves, or in a very accurate abridgement of these memoirs in the first volume of Nicholson's Journal of Natural Philosophy, &c.

We cannot conclude this article without mentioning a new kind of gunpowder, invented some years ago in France, in which the marine acid is substituted, in equal quantity, for nitre. Dr. Hutton tried some of this new powder which was made at Woolwich, and found it of about double the strength of the ordinary fort; but it is not likely to come into common and general use, for the preparation of the acid is difficult and expensive. (See Chemistry Index in this Suppl.), and the powder which is made of it catches fire and explodes from the smallest degree of heat, and without the aid of a spark. It is to this circumstance, however, that its superior strength seems to be in a great measure owing.