Charcoal, or Carbon of the French chemists, a sort of artificial coal, or fuel, consisting of halt-burnt wood. It is chiefly used, where a clear and strong fire with-out smoke is required; for the hu-midity of the wood is dissipated by the the in which it was prepared.

The art of making charcoal is very ancient; for even Solomon

(Proverb xxvi. 21), distinguishes, that kind of fuel from common fire-wood. Among the Romans, it was held in great estimation, and AEmi-lius Scaurus, the conqueror of the Ligurians, was a charcoal-mer-chant. Pliny describes the piles of wood erected by the manufacturers of this article, and observes that the blocks ought to be placed in a pyramidal form, coated with clay, and a hole left on the top for con-ducting the smoke, when the wood is set on fire. Thus, it would lbe unnecessary to describethe process, for those who employ themselves in the preparation of this article.

Properties. A surprizing num-ber of pores have, by the micro-scope, been discovered in charcoal. Dr. Hook counted, in the 18th part of an inch, 150, so that in a piece of an inch in diameter, there will be upwards of five millions. To this circumstance must be ascribed the blackness of charcoal, as the rays of light striking on it, ate received and absorbed by its pores, instead of being reflected ; consequently, the body of coal ap-pears black, - a colour arising from the want of reflection.

Charcoal may be preserved to an indefinite length of time, and in the ancient tombs of northern nations, entire pieces are frequently disco-vered. It is, therefore, deserving the attention of those, who wish to preserve valuable records from the "destructive tooth of time;" for there yet exists, according to Do-dart, charcoal made of corn (pro-bably in the days of Caesar), which is in so complete a state, that the wheat may be distinguished from the rye.

This substance is not soluble in any of the acids, but may be dis-solved in considerable quantities, by plunging it in a solution of the liver of sulphur, to which it imparts a green colour. Molted with colourless frits, or glasses, it gives a pale, dark yellow, reddish, brownish, or blackish colour, accordingly as the inflammable matter is in greater or less proportion. Fresh charcoal made of wood strongly attracts the air, and will absorb it for a considerable time ; but Dr. Priestley uniformly observed, that, after submitting it to distillation, the expelled air was less pure than that of the atmosphere, and part of it was fixed air. Hence it may occasionally be employed in a dry and powdered state, for damp and foul habitations. Lastly, Dr. Priestley has discovered that several of the metals, such as copper, iron, silver, etc. may be converted into charcoal, by passing the steam of either spirit of wine or turpentine, over them when red hot; and this, by way of distinction, he calls the charcoal of metals. As charcoal has been separated from the purest spirit of wine in the process of making aether, M. Lavoisier is of opinion, that it is one of the constituent parts, or elements, of that volatile liquid.

Uses. Besides the great advantage which charcoal affords to the artist and manufacturer, it has lately been employed with considerable success. 1. In correcting the burnt or empyreumatic taste of ardent spirits ; 2. In depriving rancid oil of its disagreeable flavour ; and 3. In restoring putrid meat. For these useful purposes, however, it is fit only when kept in close vessels, immediately after it has been prepared, so that it may absorb no acidity, or fixed air, from the common atmosphere. When employed in the two first-mentioned 1 cases, it should be previously reduced to powder, a very large rge quantity of which is required fop the rectification of distilled liquor but a smaller proportion, for purifying animal or vegetable oil, so even the common train-oil may be rendered fit for being burnt in chamber-lamps. Several manufactories of this description have lately been established in the vicinity of London, of which we shall only mention that carried on by Mr. Joshua Collier, of South-wark. From the great attraction which charcoal possesses for any kind of oily matter, or for that invisible something, formerly called giston, it is excellently adapted to become an extensively useful agent in various branches of the arts. We shall therefore communicate the following abstract of the late discoveries made on this subject, chiefly by Prof. Lowitz, of St. Petersburgh. This philosopher found, that charcoal rendered the crystals of tartar very white and pure, when employed in preparing them ; that the marine and nitrous acids are decomposed by being dis-tilled upon it; that the red juices of vegetable fruits are deprived of their colour, without losing part of their acidity; that brown, rancid oils are rendered sweet and clear, by agitating them for some days with charcoal in powder; that it changes the smell of putrid vegetables to that of a pure volatile alkali, and produces the same effect on fresh meat. By boiling coals in powder, with honey, the pure saccharine parts of the latter are said to be separated, and the honey to become a well-tasted sugar. Vine-gar concentrated by freezing, and distilled from a large portion of powdered coal, is extremely strong pure, and fragrant. Corn-spirit, merely shaken with coal, loses its bad flavour) and, if honey be added, it becomes a sweet and plea-sant liquor. Even the tainted fla-r of ardent spirits, when impregnated with any vegetable oils, may in a similar manner be stroved ; and, if the spirit be distilled, the residuum is said not to be brown ; so that no inconvenience will arise from carrying the distillation loo far.—T were produced by every kind of coal, whether fossil or charred vegetable substances ; though the latter appear to us, in many respects, preferable to coke. There are considerate ences in the coals of various vegetables, with respect to their habitude to fire : the very light < of linen, cotton, some fingi, etc. quickly catch fire from a spark, and soon consume: the more dense ones of woods, and roots, are set on fire with greater difficulty, and burn more slowly; the coals of the black berry-bearing alder, of the hazel, willow, and lime-tree, are the most proper for making gunpowder, and other pyrotcchnical compositions. For the reduction of metallic calces, those of heavier woo 1, as oak and beech, are preferable ; because these appear to contain a larger proportion of the inflammable principle, and perhaps in a more fixed state. Considered as common fuel, those of the heavy woods afford the greatest heat, and require a most abundant supply of air, in order to keep them burning; on the contrary, the coals of the light woods retain a glowing heat, till they are consumed, without a strong draught of air; the bark usually crackles while burning, which is seldom the case wi the coal of the wood itself.

Charcoal is likewise foconsider.vice to different artists, polishing brass and copperplates, after they en ru bed clean with powdered puceHorn-plates lished in a similar manner, and a gloss afterwards given with tripoli. — Coals of different sub-stances are also used as pigments ; hence the bone the shops. Most kind are not only incorrputible, but also possess the advantage of a full colour, and work freely in all the forms, where powdery pigments are but they ought to be carefully prepared, by thoroughly burning the substance in a close vessel, and afterwards reducing the coal to a fine powder. —In drawing outlines, the arist avails himself of pieces of charcoal, the marks of which may b easily rubbed out. For this purpose, the smaller branches of a tree, such as the willow and vine, are usually preferred; and which, alter being freed from the bark and pith, afford the best drawing pencils. Dr. Lewis remarks, that the shells and stones of fruit yilded cods, so hard that they would with difficulty mark on paper, while those of the kernels of truit were very soft and mellow. All these experiments must be conducted in proper closely covered (the barrels of old guns, or pistols, may occasionally serve as substitutes). The Doctor 1< gated various coals into fine powder, mixed them with gum-water a oil, and applied them as paints, diluted with different degrees of white. When laid on thick, they all appeared of a strong, full black ; nor could it be discerned, that one was of a finer colour than another; but those diluted with white, or spread thin, had a blueish cast.— Horns, and the bones, both of fish and land animals, produced coals more glossy, and of a deeper co-Jour, than vegetables; and which, in general, were so hard that paper could scarcely be stained with them : but silk, wool, leather, blood, and the fleshy parts of animals, yielded soft coals. Some of these remarkably differed from others, in colour; that of ivory being superior to all, and doubtless the finest of black produced by fire.

In agriculture, charcoal has, in many parts of France and the Netherlands, been substituted for turf-ashes, as a manure; but M. RaULIN is of opinion, that it is attended with pernicious effe6ts on the soil, the vegetables it produces, and the animals that feed upon its productions.

Besides these various purposes to which charcoal is daily applied, it also promises to be of considerable service in medicine; on account of its absorbent and antiseptic properties. (See BrEAth, p. 335.) From a late account given by Dr. MetzlEr, an eminent physician in Germany, we ! the following extraordinary fact: The corpse of a person that had been murdered twelve days, was brought before a coroner's inquest ; and, contrary to the expectation of the court, there was not the least mark of putrefaction, nor any of-fensive smell percentible. On opening the intestines of the abdo-were found in an unity dry state. The cause of this phenomenon was soon discovered; for it appeared in the course of examination, that the body had been kept for the whole time buried in dry coals coarsely pounded, at least twelve inches deep. It was still more remarkable, " that the cartaligenous parts, especially those of the breast, had acquired a degree of softness, resembling that of butter." — We submit the application of this singular property to the discernment of our readers.

With regard to the treatment of persons suffocated by the deleterious vapour of charcoal, we shall in this place only observe, that a body in that unfortunate situation, ought to be without delay exposed to the strongest draught of cold air; all the garments loosened; volatile spirits held to the nostrils ; the body rubbed either with vine* gar, or with a diluted spirit of sal ammoniac; the face should be turned towards the ground, and the head, breast, back, etc. either washed with, or the whole body suddenly plunged into, cold water ; then dried, and again washed with vinegar; stimulating clysters repeatedly administered, and venesection performed at the jugular vein, or, for want of medical assistance, a number of leeches applied to the neck and tempies.—Of the particular circumstances connected with this treatment, we propose to give a move detailed account, under the head of Suffocation.