See that article Encycl. and Caloric and Combustion, Chemistry Index in this Suppl.

EXTINCTION OF FIRE is sometimes a matter of so much consequence, that everything which promises to be effectual for that purpose is worthy of attention. In the nineteenth number of Mr Nicholson's Journal of Philosophy, Chemistry, and the Arts, we have the following composition for extinguishing fire, invented by M. Von Aken.

Burnt alum pounds 30 Green vitriol powdered 40 Cinabre or red ochre in powder 20 Potters' clay, or other clay, also powdered 200 Water 630

With 40 measures of this mixture an artificial fire was extinguished under the direction of the inventor by three persons, which would have required the labour of 20 men and 1500 measures of common water. Sig. Fabbroni was commissioned to examine the value of this invention, and found in his comparative trials with engines of equal power, worked by the same number of men, that the mixture extinguished the materials in combustion in one fifth part less time, and three eighths less of fluid than when common water was used. He observed, as might indeed have been imagined from the nature of the material, that the flame disappeared wherever the mixture fell, and that the saline, metallic, and earthy matters formed an impenetrable lute round the hot combustible matter, which prevented the access of the air, and consequently the renewal of the destructive process.

This recipe, Mr Nicholson informs us, is taken from the 85th No. of the Giornale Letterario di Napoli, in which it was inserted in the form of a letter from Sig. Fabbroni to Sig. D. Luigi Targioni of Naples; and the author of the letter estimates the price of the composition at about one halfpenny per pound.

The reason assigned by Mr Nicholson for giving this abridged account a place in his valuable work, will be admitted by him and the public as a sufficient reason for our adopting it into our's. It is, that such inventions are worthy of the attention of philosophers and economists, even though in the first applications they may prove less advantageous than their inventors may be disposed to think. It is scarcely probable that this practice in the large way, with an engine throwing upwards of 200 gallons (value about L.3, 10s.) each minute, would be thought of or adopted, or that a sufficient store of the materials would be kept in readiness; since at this rate the expenditure for an hour would demand a provision to the amount of L.210. sterling. But in country places the process, or some variation of it, might be applied with sufficient profit in the result; more especially if it be considered that common salt or alum, or such saline matter as can be had and mixed with the water, together with clay, chalk, or lime, ochreous earth or common mud, or even these last without any salt, may answer the purpose of the late with more or less effect, and extinguish an accidental fire with much greater speed and certainty than clear water would do.

Fire-Balls are meteors, of which some account has been given in the Encyclopaedia, as well as of various hypotheses which have been framed respecting their nature and their origin. Since that article was published, a new and very singular hypothesis has been framed by Professor Chladni of Wittenberg, who maintains it by arguments, which, however fanciful, are yet worthy of the reader's notice.

He supposes that fire-balls, instead of being collections of the electrical fluid floating in the highest regions of our atmosphere, are masses of very dense matter formed in far distant parts of space, and subjected to similar laws with the planets and comets. He endeavours to prove that their component parts must be dense and heavy; because their course shows, in no apparent manner, the effects of gravity; and because their mass, though it diffuses to a monstrous size, retains sufficient consistency and weight to continue an exceedingly rapid movement through a very large space, without being decomposed or dissolved, notwithstanding the resistance of the atmosphere. It seems to him probable, that this substance is by the effect of fire reduced to a tough fluid condition; because its form appears sometimes round and sometimes elongated, and as its extending till it bursts, as well as the bursting itself, allows us to suppose a previous capability of extension by elastic fluidity. At any rate it appears to be certain, that such dense matter at so great a height is not collected from particles to be found in our atmosphere, or can be thrown together into large masses by any power with which we are acquainted; that no power with which we are acquainted is able to give to such bodies so rapid a projectile force in a direction almost parallel to the horizon; that the matter does not rise upwards from the earth, but exits previously in the celestial regions, and must have been conveyed thence to our earth. In the opinion of Dr Chladni, the following is the only theory of this phenomenon that agrees with all the accounts hitherto given, which is not contrary to nature in any other respect, and which besides seems to be confirmed by various masses found on the spot where fire-balls fell.

As earthly, metallic, and other particles form the principal component parts of our planets, among which iron is the prevailing part, other planetary bodies may therefore consist of similar, or perhaps the same component parts, though combined and modified in a very different manner. There may also be dense matters accumulated in smaller masses, without being in immediate connection with the larger planetary bodies dispersed throughout infinite space; and which, being impelled either by some projecting power or attraction, continue to move until they approach the earth or some other body, when, being overcome by its attractive force, they immediately fall down. By their exceedingly great velocity, still increased by the attraction of the earth and the violent friction in the atmosphere, a strong electricity and heat must necessarily be excited; by which means they are reduced to a flaming and melted condition, and great quantities of vapour and different kinds of gases are thus disengaged, which diffuse the liquid mass to a monstrous size; till, by a still farther expansion of these elastic fluids, it must at length burst.

Dr Chladni thinks also, that the greater part of the floating flares, as they are called, are nothing else than fire-balls; which differ only from the latter in this, that their peculiarly great velocity carries them past the earth at a greater distance, so that they are not so strongly attracted by it as to fall down; and therefore, in their passage through the high regions of the atmosphere, occasion only a transient electric flash, or actually take fire for a moment, and are again speedily extinguished, when they get to such a distance from the earth that the air becomes too much rarefied for the existence of fire.

The grounds on which Dr Chladni supports this opinion are various relations, well authenticated, of the motions of those meteors, and the phenomena which accompany their bursting. Besides those mentioned in the Encyclopaedia, he lays a particular stress on the account which he received from M. Baudin, Professor of philosophy at Pau, of a remarkable fiery meteor seen in Gafiony on the 24th of July 1795. On the evening of that day M. Baudin was in the court of the castle of Marne with a friend, the atmosphere being perfectly clear, when they suddenly found themselves surrounded by a whitish light, which obscured that of the full moon, then shining with great lustre. On looking upwards, they observed, almost in their zenith, a fire ball of a larger diameter than the moon, and with a tail equal in length to five or six times the diameter of the body. The ball and the tail were of a pale white colour, except the point of the latter, which was almost as red as blood. The direction of this meteor was from south to north.

"Scarcey (says M. Baudin) had we looked at it for two seconds when it divided itself into several portions of considerable size, which we saw fall in different directions, and almost with the same appearance as the bursting of a bomb. All these different fragments became extinguished in the air; and some of them, in falling, assumed that blood-red colour which I had observed in the point of the tail. It is not improbable that all the rest may have assumed the same colour; but I remarked only those which proceeded in a direction towards Mormes, and which were particularly exposed to my view.

"About two minutes and a half, or three minutes after, we heard a dreadful clap of thunder, or rather explosion, as if several large pieces of ordnance had been fired off together. The concussion of the atmosphere by this shock was so great, that we all thought an earthquake had taken place. The windows shook in their frames, and some of them, which probably were laid to and not closely shut, were thrown open. We were informed next day, that in some of the houses at Houga, a small town about half a mile distant from Mormes, the kitchen utensils were thrown from the shelves; so that the people concluded there had been an earthquake. But as no movement was observed in the ground below our feet, I am inclined to think that all these effects were produced merely by the violent concussion of the atmosphere.

"We proceeded into the garden while the noise still continued and appeared to be in a perpendicular direction above us. Some time after, when it had ceased, we heard a hollow noise, which seemed to roll along..." the chain of the Pyrenees in echoes, for the distance of fifteen miles. It continued about four minutes, becoming gradually more remote, and always weaker; and at the same time we perceived a strong smell of sulphur.

"While we were endeavouring to point out to some persons present the place where the meteor had divided itself, we observed a small whitish cloud, which arose perhaps from the vapour of it, and which concealed from us the three stars of the Great Bear, lying in the middle of those forming the semicircle. With some difficulty, however, we could at last distinguish these stars again behind the thin cloud. There arose, at the same time, a fresh gentle breeze.

"From the time that elapsed between the bursting of the ball and the explosion which followed, I was inclined to think, that the meteor was at the height of at least seven or eight miles, and that it fell four miles to the north of Mormes. The latter part of my conjecture was soon confirmed by an account which we received, that a great many stones had fallen from the atmosphere at Juliac, and in the neighbourhood of Barbotan. One of these places lies at the distance of about four miles to the north of Mormes, and the other at about the distance of five to the north-north-west."

M. de Carrits Barbotan, the friend who was with the Professor in the court and garden of Mormes when the meteor first attracted their attention, was at Juliac two days afterwards, and confirmed to him the truth of this circumstance. It appeared, likewise, from the account of several intelligent persons, highly worthy of credit, that the meteor burst at a little distance from Juliac, and that the stones which fell were found lying in a space almost circular, about two miles in diameter. They were of various sizes. Some were seen to fall, which, when found, weighed 18 or 20 pounds, and which had sunk into the earth from two to three feet. M. de C. Barbotan transmitted one weighing 18 pounds to the academy of sciences at Paris; and M. Baudin was told, that some were found which weighed even 50 pounds. He examined a small one, and found it very heavy in proportion to its size: it was black on the outside; of a greyish colour in the inside, and interspersed with a number of small shining metallic particles. On striking it with a piece of steel, it produced a few small dark red sparks, not very lively. A mineralogist, to whom a like piece of stone from the same meteor was shown at Paris, described it as a kind of grey flint mixed with calcareous spar, the surface of which exhibited vitrified blackish eaux of iron. The Professor was told also, that some stones were found totally vitrified.

Such (says Dr Chladni) is the account given by Baudin of this meteor; the phenomena of which he endeavours to explain from accumulations in the upper parts of the atmosphere.

According to all the observations hitherto made with any accuracy on fire-balls, the height at which they were first perceived was always very considerable, and by comparing the angles under which they were seen from different points, often 19 German miles, and even more; their velocity, for the most part, several miles in a second; and their size always very great, often a quarter of a mile, and even more, in diameter. They were all seen to fall mostly in an oblique direction; not one of them ever proceeded upwards. All of them have appeared under the form of a globular mass, sometimes a little extended in length and highly luminous; having behind it a tail, which, according to every appearance, was composed of flames and smoke. All of them burnt after they were seen to move through a large space, sometimes over several districts, with an explosion which shook everything around. In every instance where there has been an opportunity of observing the fragments that fell after they burnt, and which sometimes have sunk to the depth of several feet into the earth, they were found to consist of scoriaceous masses, which contained iron in a metallic or calcined state, pure, or else mixed with different kinds of earth and sulphur. All the ancient and modern accounts, written partly by naturalists and partly by others, are essentially similar, that the one seems to be only a repetition of the other. This conformity in accounts, the authors of which knew nothing of those given by others, and who could have no interest in fabricating similar tales, can scarcely have arisen from accident or fiction, and gives to the related facts, however inexplicable many of them may seem, every degree of credibility.

In the third volume of Pallas's Travels, we have an account of a mass of iron discovered by him in Siberia, which Dr Chladni considers as having been undoubtedly a fire-ball, or the fragment of a fire-ball. This problematical mass was found between Krasnojarsk and Abakan in the high slate mountains, quite open and uncovered. It weighed 1600 pounds; had a very irregular and somewhat compressed figure like a rough granite; was covered externally with a ferruginous kind of crust; and the inside consisted of malleable iron, brittle when heated, porous like a large sea sponge, and having its interstices filled with a brittle hard vitrified substance of an amber yellow colour. This texture and the vitrified substance appeared uniformly throughout the whole mass, and without any traces of slag or artificial fire.

Dr Chladni shows, with a great deal of ingenuity, that this mass neither originated by the wet method, nor could have been produced by art, the burning of a forest, by lightning, or by a volcanic eruption. It appears to him, therefore, in the highest degree probable, that it is of the same nature with fire-balls, or, as they have sometimes been called, flying dragons. The Tartars, as we are informed by Pallas, considered this mass as a sacred relic which had dropped down from heaven; and this circumstance Dr Chladni considers as no slight confirmation of his opinion, which he further supports by the following reasonings:

"1. As fire-balls consist of dense and heavy substances, which, by their exceedingly quick movement, and the friction thence excited by the atmosphere, become electric, are reduced to a state of ignition, and melted by the heat, so that they extend to a great size, and burst; it thence follows, that in places where fragments, produced by the bursting of a fire-ball, have been found, substances endowed with all these properties must also have been found. Iron, however, the principal component part of all the masses hitherto found (and he speaks of many besides that of Pallas), possesses all these properties in a very eminent degree. The weight and toughness of the principal component parts of fire-balls, which... which must be very considerable; since, with the greatest possible distention, they retain confidence enough to proceed with the utmost velocity through such an immense space without decomposition of their mass, and without their progress being obstructed by the resistance of the air, agree perfectly well with melted iron; their dazzling white light has by many observers been compared to that of melted iron; iron also exhibits the same appearances of flaming, smoking, and throwing out sparks, and all these phenomena are most beautiful when they take place in vital air. Of the extension by elastic fluids expanded by the heat, and of the contraction which follows from cold, traces may be discovered in the internal spongy nature of the iron masses which have been found, and in the globular depressions of the exterior hard crust; the latter of which gives us reason to suppose, that in these places there have been air-bubbles, which, on cooling, sunk down. The mixture of sulphur found in various masses, agrees also exceedingly well with the phenomena of fire-balls, and especially with the great inflammability of sulphur in very thin impure air; for it is well known, that sulphur in an air-pump will take fire in air in which few other bodies could do the same. In regard to those masses in which no sulphur was found, this may have arisen from the sulphur escaping in vapour, since some time after the appearance of fire-balls a strong smell of sulphur has been perceived. The brittleness of the Siberian iron mass when heated, may arise from some small remains of sulphur, which may perhaps be the cause of the facility with which fragments of this mass, as well as of another found at Aix-la-Chapelle, could be roasted.

"2. The whole texture of the masses betrayed evident signs of fusion. This, however, cannot have been occasioned by any common, natural, or artificial fire; and particularly for this reason, because iron so malleable is not fusible in such fire, and when it is fused by the addition of inflammable matters, loses its malleability, and becomes like common raw iron. The vitrified substance in the Siberian mass is equally incapable of being fused in a common fire. The fire, then, must have been much stronger than that produced by the common, natural, and artificial means; or the fusion must have been effected by the force of exceedingly strong electricity; or perhaps both causes may have been combined together.

"3. It is totally incomprehensible how, on the high slate mountains, where the Siberian mass was found, at a considerable distance from the iron mines; in the chalky soil of the extensive plains of America, where for a hundred miles around there are no iron mines, and not even so much as a stone to be found; and at Aix-la-Chapelle, where, as far as the author knows, there are no iron works—so many ferruginous particles could be collected in a small space as would be necessary to form masses of 1600, 15,000, and 17,000, up to 33,600 pounds. This circumstance shows, that these masses could as little have been fused by lightning as by the burning of a forest or of fossil coal. These masses were found quite exposed and uncovered, and not at any depth in the earth, where we can much more readily admit such an accumulation of ferruginous particles to have been melted by the effects of lightning.

"Should it be asked, how such masses originated, or by what means they were brought into such an inflated position? this question would be the same as if it were asked how the planets originated. Whatever hypotheses we may form, we must either admit that the planets, if we except the many revolutions which they may have undergone, either on or near their surface, have always been since their first formation, and ever will be the same; or that nature, acting on created matter, possesses the power to produce worlds and whole systems, to destroy them, and from their materials to form new ones. For the latter opinion there are, indeed, more grounds than for the former, as alternations of destruction and creation are exhibited by all organized and unorganized bodies on our earth; which gives us reason to suspect that nature, to which greatness and smallness, considered in general, are merely relative terms, can produce more effects of the same kind on a larger scale. But many variations have been observed on distant bodies, which, in some measure, render the last opinion probable. For example, the appearing and total disappearing of certain stars, when they do not depend upon periodical changes. If we now admit that planetary bodies have started into existence, we cannot suppose that such an event can have otherwise taken place, than by conjecturing that either particles of matter, which were before dispersed through infinite space in a more soft and chaotic condition, have united together in large masses by the power of attraction; or that new planetary bodies have been formed from the fragments of much larger ones that have been broken to pieces, either perhaps by some external shock, or by an internal explosion. Let whichever of these hypotheses be the truest, it is not improbable, or at least not contrary to nature, if we suppose that a large quantity of such material particles, either on account of their too great distance, or because prevented by a stronger movement in another direction, may not have united themselves to the larger accumulating mass of a new world; but have remained insulated, and, impelled by some shock, have continued their course through infinite space, until they approached so near to some planet as to be within the sphere of its attraction, and then by falling down to occasion the phenomena before mentioned."

Whether Chladni be a philosopher of the French school we know not; but some parts of his theory tend strongly towards materialism; and the arguments by which he attempts to prop those parts are peculiarly weak. When he talks of Nature producing worlds, he either substitutes Nature for Nature's God, or utters jargon which has no meaning. In what sense the word Nature is used by every philosopher of a sound mind, we have elsewhere been at some pains to show (see River, p. 116, Encycl.) but how absurd would it be to say, that the system of general laws, by which the Author and Governor of the universe connects together its various parts, and regulates all their operations, possesses, independently of him, "the power to produce worlds and whole systems, to destroy them, and from their materials to form new ones?"

As Chladni admits, or talks as if he admitted, the creation of matter, it would be wrong to impute to him this absurdity; but if by Nature he means God, and he can consistently mean nothing else, we beg leave to affirm, that it is directly contrary to every notion which which we can form of Nature in this sense, "to suppose that a large quantity of material particles, either on account of their distance, or because prevented by a strong movement in another direction, have not united themselves to the larger accumulating mass of a new world, but remained insulated, and impelled by some shock, have continued their course through infinite space, &c." Is there any distance to which God cannot reach, or any movement so strong as to resist his power? Our author's language is indeed confused, and probably his ideas were not very clear. When he speaks of the particles of matter being at first dispersed through infinite space, and afterwards united by the power of attraction, he revives the question which was long ago discussed between Newton and Bentley, and discussed in such a manner as should have silenced forever the babblings of those who form worlds by attraction.

"The hypothesis (says Newton) of matter's being at first evenly spread through the heavens, is, in my opinion, inconsistent with the hypothesis of innate gravity without a supernatural power to reconcile them; and therefore infers a Deity. For if there be innate gravity, it is impossible now for the matter of the earth, and all the planets and stars, to fly up from them, and become evenly spread through all the heavens, without a supernatural power; and certainly that which can never be hereafter without a supernatural power, could never be heretofore without the same power." Dr Chladni, indeed, does not say that his particles of matter were evenly dispersed through infinite space; but such must be his meaning, if he has any meaning: for matter was evenly dispersed, by an innate attraction, be united as soon as it exists, and so united as not to leave small fragments of it to wander, we know not why, through the trackless void. Turn matter on all sides, make it eternal or of late production, finite or infinite, there can be no regular system produced but by a voluntary and meaning agent; and therefore, if it be true that fire-balls are masses of dense matter, coeval with the planetary system, existing in the celestial regions, and thence conveyed to our earth, they must have been formed, and their motions impressed upon them, by the Author of Nature for some wise purpose, though by us that purpose may never be discovered. One thing seems pretty clear, that wherever they may be formed, the phenomena attending their hurrying, account sufficiently for the notions of thunderbolts which have been generally entertained in all ages, and in every country.

Greek Fire (see Wild Fire, Emecy). In the second volume of Mr Nicholson's Philosophical Journal, we have the following receipt for making this composition, taken from some manuscripts of Leonard de Vinci, who flourished in the end of the fifteenth and beginning of the sixteenth centuries, and who appears to have advanced far before his contemporaries in physical science. Take the charcoal of willow, nitre, brandy, resin, sulphur, pitch, and camphor. Mix the whole together over the fire. Plunge a woollen cord in the mixture, and form it into balls, which may afterwards be provided with spikes. These balls, being set on fire, are thrown into the enemy's vessels. It is called the Greek fire, and is a singular composition, for it burns even upon the water. Callimicus the architect taught this composition to the Romans (of Constantinople), who derived great advantage from it, particularly under the emperor Leo, when the Orientals attacked Constantinople. A great number of their vessels were burned by means of this composition.

The composition of the Greek fire thus given by Vinci is found in nearly the same words in some of the writings of Baptista Porta; whence it appears that both authors derived their information from the same source. A composition which burnt without access to the atmosphere could not fail to fill the minds of our forefathers with wonder; but the modern discoveries in chemistry have disclosed the secret, by shewing, that the combustion is carried on by means of the oxygen contained in the niter.

Rafant or Ravant Fire, is a fire from the artillery and small arms, directed parallel to the horizon, or to those parts of the works of a place that are defended.

Running Fire is when ranks of men fire one after another; or when the lines of an army are drawn out to fire on account of a victory; in which case each squadron or battalion takes the fire from that on its right, from the right of the first line to the left, and from the left to the right of the second line, &c.