« ZurückWeiter »
this being the indication of all the watery intense. In ordinary heat the ashes de vapour being gone, and the burning of the not melt, and though they are more copious true coaly matter commencing. Thus is a and heavy than those of charcoal of wood, pretty strong red heat raised through the they seldom choke up the fire considerably, whole mass, and all the volatile matters are unless the bars of the grate be too close dissipated by it, and nothing now remains together. but the charcoal. The holes being all stop This fuel, therefore, is preferable, in most ped in succession, as this change of the cases, to the charcoal of wood, on account smoke is observed, the fire goes out for of its burning much longer, or giving much want of air. The pile is now allowed to more heat before it is consumed. The cool. This requires many days; for, char- heat produced, by equal quantities, by coal being a very bad conductor of heat, weight of pil-coal, wood-charcoal and wood the pile long remains red hot in the centre, itself, are nearly in proportion of 5, 4, and and, if opened in this state, would instantly 3. The reason why both these kinds of burn with fury.
charcoal are preferred, on most occasions, Small qnantities may be procured at any in experimental chemistry, to the crude time, by burning wood in close vessels. wood, or fossil coal, from which they are · Little pieces may be very finely prepared, produced, is, that the crude fuels are de
at any time, by plunging the wood in lead prived, by charring, of a considerable melted and red hot.
quantity of water, and some other volatile This is the chief fuel used by the chemists principles, which are evaporated during abroad, and has many good properties. It the process of charring, in the form of kindles quickly, emits few watery or other sooty smoke or fame. These volatile tapours while burning, and when consumed parts, while they remain in the fuel, make leaves few ashes, and those very light. it unfit (or less fit) for many purposes in They are, therefore, easily blown away, so chemistry. For besides obstructing the that the fire continues open, or pervious to vents with sooty matter, they require much the current of air which must pass through heat to evaporate them; and therefore, it to keep it burning. This sort of fuel, the heat of the furnace, in which they too, is capable of producing as intense a are burnt, is much diminished and wasted heat as can be obtained by any; but in by every addition of fresh fuel, until the those violent heats it is quickly consumed, fresh fuel is coinpletely inflamed, and and needs to be frequently supplied. restores the heat to its former strength.
Fossil coals charred, called cinders, or But these great and sudden variations of coaks, have, in many respects, the same the heat of a furnace are quite inconveniproperties as charcoal of wood; as kindling ent in most chemical processes. In the more readily in furnaces than when they greater number of chemical operations, are not charred, and not emitting watery, therefore, it is much more convenient to or other gross smoke, while they burn, use charred fuel, than the same fuel in its This sort of charcoal is even greatly supe, natural state. rior to the other in some properties.
There are, at the same time, some kinds It is a much stronger fuel, or contains the of fossil coal, which are exceptions to what combustible matter in greater quantity, or has now been delivered in general. We in a more condensed state. It is, therefore, meet with some of them that leave a consumed much more slowly on all occa smaller proportion of ashes than others, sions, and particularly when employed for and the ashes of some are not so liable to producing intense melting heats. The only melt in violent heats. There is one species inconveniences that attend it are, that, as too, such as the Kilkenny coal of Ireland, it consumes, it leaves much more ashes than and which occurs likewise in some parts the other, and these much heavier too, of this country, that does not contain any which are, therefore, liable to collect in such sensible quantity of water, or other such quantity as to obstruct the free passage of volatile principles. But this may be called air through the fire ; and further, that when a sort of native charcoal. It has the apthe heat is very intense these ashes are dis- pearance of ordinary coal, but, when thrown posed to melt or vitrify into a tenacious into the fire, does not emit smoke or soot. drossy substance, which clogs the grate, the It merely becomes red, gives a subtile sides of the furnace and the vessels. This blue flame, and consumes like charcoal ; last inconvenience is only troublesome, only it lasts surprizingly long, or continues however, when the heat required is very to give heat for a very long time before it
is totally consnined. But it cannot be diminution of heat. And if much air made to burn so as to produce a gentle be admitted to make those vapours break heat. If not in considerable quantity, and out into flame, the heat is too violent. violently beated, it is soon extinguished. These flaming fuels, however, have their
In using this kind of fuel, it is proper to particular uses, for which the others are far be on our guard against the dangerous less proper. For it is a fact, that flame, nature of the burnt air, which arises from when produced in great quantity, and charcoal of all kinds. Charcoal burns made to burn violently, by mixing it with without visible smoke. The air arising a proper quantity of fresh air, by driving from it appears to the eye as pure and as it on the subject, and throwing it into clear as common air. Hence it is much whirls and eddies, which mix the air with used abroad by thuse who are studions of every part of the hot vapour, gives a most neatness and cleanliness in their apartments. intense heat. This proceeds from the But this very circumstance should make vaporous nature of flame, and the perfect 125 more watchful against its effects, which miscibility of it with the air. may prove dangerous, in the highest de As the immediate contact and action of gree, before we are aware of it. The air air is necessary to the burning of every arising from common crude fuel is no doubt combustible body; 80 the air, when proas bad, but the smoke renders it disagree- perly applied, acts, with far greater ad. able before it become dangerous. The vantage on flame, than on the solid and first sensation is a slight seuse of weakness; fixed inflammable bodies: for when air the limbs seem to require a little atten- is applied to these last, it can only act on tion, to prevent falling. A slight giddi- their surface, or the particles of them that ness, accompanied by a distinct feeling are outermost; whereas flame being a of a flush, or glow in the face and neck. vapour or elastic Anid, the air, by proper Soon after, the person becomes drowsy, contrivances, can be intimately mixed with would sit down, but commonly falls on the it, and made to act on every part of it, floor insensible of all about him, and external and internal, at the same time. breathes strong, snoring as in an apoplexy. This great power of fame which is the conIf the person is alarmed in time, and quence of this, does not appear when we escapes into the open air, he is commonly try'small quantities of it, and allow it to seized with a violent head-ach, which gra- burn 'quietiy, because the air is not indually abates.
timately mixed with it, but acts only on But when the effect is 'completed, as the outside, and the quantity of burning above described, death very soon ensues, matter in the surface of a small flame is unless relief be obtained. There is usually too small to produce much effect. a foaming at the mouth, a great flush or But when flame is produced in large suffusion over the face and neck, and every quantity, and is properly mixed and agitatindication of an oppression of the brain, ed with air, its power to heat bodies is by this accumulation of blood. The most immensely increased. It is therefore pecusuccessful treatment is to take off a quan liarly proper for heating large quantities tity of blood immediately, and throw cold of matter to a violent degree, especially if water on the head repeatedly. A strong the contact of solid fuel with such matter stimulus, such as hartshorn, applied to the is inconvenient. Flaming fuel is used for soles of the feet, has also a very good this reason in many operations performed effect.
on large quantities of metal, or metallic The fifth and last kind of fuel is wood, minerals, in the making of glass, and in the or fossil coals, in their crnde state, which it baking or burning of all kinds of earthern is proper to distinguish from the charcoals The potter's kiln is a cylindrical of the same substances. The difference cavity, filled from the bottom to the top consists in their giving a copious and bright with columns of wares, the only interstices flame, when plenty of air is admitted to are those that are left between the columns; them, in consequence of which they must and the flame, when produced in sufficient be considered as fuels very different from quantity, proves a torrent of liquid fire, charcoal, and adapted to different purposes. constantly flowing up through the whole See FLAME.
of the insterstices, and heats the whole pile Flaming fuel cannot be managed like in an equal manner. the charcoals. If little air be admitted, it Flaming fuel is also proper in many gives no flame, but sooty vapour, and a works or manufactories, in which much fuel
is consumed, as in breweries, distilleries, Ay is one of the most curious of insects, it and the like. In such works, it is evidently is three inches long, and the breadth be. worth while to contrive the furnaces so that tween the tips of the expanded wings is heat may be obtained from the volatile about five or six inches. This beautiful parts of the fuel, as well as from the fixed; insect is a native of Surinam and other parts for when this is done, less fuel serves the of South America, and during the night it purpose than would otherwise be neces diffuses so strong a phosphoric splendor sary. But this is little attended to, or ill from its head, which is nearly as large as understood in many of those manufactories. the rest of the body, that it may be emIt is not uncommon to see vast clouds of ployed for the purpose of a candle or black smoke and vapour coming out of torch. their vents. This happens in consequence FULICA, the gallinule and the coot, in of their throwing too large a quantity of natural history, a genus of birds of the orcrude fuel, into the furnace at once. The der Grallæ. Generic character: bill strong, heat is not sufficient to inflame it quickly, thick, and sloping to the point ; upper manand the consequence is a great loss of heat. dible arched over the lower at the edge, See LABORATORY.
and reaching far up the forehead ; nostrils FUGUE, in music, signifies a composi- nearly oval; front bald; toes four, long tion, in which one part leads off some de- and furnished with broad scalloped memtermined succession of notes called the sub- branes. There are twenty-five species. ject, which after being answered in the F.atra-coot, is distinguished from the galli. fifth and eighth by the other parts, is inter- nule by pinnated feet. It inhabits Europe, spersed through the movement, and distri- Asia, and America, and is about the size of buted amid all the parts in a desuitory man a small fowl. It feeds on small fish and ner at the pleasure of the composer. There water-insects, is common in some parts of are three distinct descriptions of fugues, the this country at all seasons, but in the breedsimple, which contains but one subject; the ing season is seen almost always in pairs, double, that which consists of two subjects; about the borders of ponds and lakes well and the counter fugue, is that in which the fringed with roshes, of which it mats itself a subjects move in a direction contrary to large nest, said to be often observed floateach other.
ing on the water. These birds are deFUIRENA, in botany, so named in me voured when young by the buzzards, which mory of George Fuiren, a genus of the infest their haunts, and prevent them from Triandria Monogynia class and order. Na- that great multiplication which might be tural order of Calamariæ. Cyperoideæ, otherwise expected. Rallus crex, or the Jussieu. Essential character : ament im- crake gallinule, is found in various parts of bricate, with awned scales ; calyx none; Europe, and is particularly abundant in corolla with three-petal shaped obcordate Ireland, where it is supposed by Latham to glumes, ending in a tendril. There is but winter. Wherever quails are, the crake is one species, viz. F. paniculata, a lofty to be met with. It runs fast, but fies with grass. Native of Surinam and Jamaica.
great awkwardness, with its legs banging FULCRUM, in mechanics, the prop or down. Its food is grain apd insects. On its support, by which a lever is sustained. See arrival in England, where it is migratory, it MECHANICS.
is poor and emaciated, but fattens afterFULGORA, in natural history, lantern wards with great rapidity, and is esteemed fly, a genus of insects of the order Hemip- excellent for the table. Its full weight is tera. Head hollow, inflated, extended fur- about eight ounces. ward; antennæ short, seated beneath the F. porphyrio or the purple water hen, eyes, consisting of two joints, the outer occurs in almost all the warmer latitudes of one larger and globular ; snout elongated, the globe. It is of the size of a fowl; in inflected, four-jointed; legs formed for Sicily is kept merely for its beauty, and in walking. There are about 25 species, al. Persia exhibits its greatest elegance of most inhabitants of hot climates. Mr. plumage. It is tamed with great ease, and Donovan has described the F. Europæa; will feed very quietly in the farm-yard on the body of which is green; wings hyaline, grain or roots, but is particularly fond of reticulate ; front conic. This is a small fishes, which it plunges in the water before insect, and destitute of the shining quality, it takes them to its mouth. Standing op by which foreign species are distinguished. one leg it employs the other as a hand in But the F. lanternaria, or Peruvian lantern many cases, particularly in lifting its food
to its mouth, in the same manner as a par. dually in bulk, and falls into a fine soft rot.
powder. · F. chloropus, or the common water-hen, It is of great use in scouring cloths, stuffs, is found in various parts of England, haunt- &c. imbibing all the grease and oil used in ing the borders of ponds and rivers, which preparing, dressing, &c. of the wool. It abound in weeds, and breeding twice in a does not effervesce with the acids: before season. It flies aukwardly, but runs and the blow-pipe it melts with a brown spongy swims well. Its flesh is thought excellent, scoria : it consists of and its general weight is about fifteen
Silex ............ 51.8 ounces. Rallus Carolinus, or the American
Alumine 25. water-ben, is as large as a quail. In the be.
Lime........ 3.3 ginning of autumn these birds are found in
Magnesia ...... 0.7 Virginia in extreme abundance. From a
Oxide of iron.. 3.7 state of perfect leanness they speedily be
15.5 come so fat as to be incapable of Aying,
100.0 and are knocked off the reeds of the marsbes by the paddles of the Indians, who make pleasurable excursions in their canoes Fuller's earth is not now in so much refor this purpose, and in the course of one quest in the country as it was formerly, night a party will take ten or twelve huz- owing to the almost general use of soap. In dred of them. They are extremely admired England it is found in beds, covered by, and for food, and supply part of the daily re resting upon, that peculiar sand-stone formapast of every planter during their short sea tion, which accompanies and serves as the son. Rallus parzana, or the spotted galli- foundation to chalk: its colour is yellowish nola, is found in Cumberland, and supposed grey, with a faint tinge of green. It is to be migratory. It is fond of solitude, and found in Hampshire, Bedfordshire, and in unless in breeding time, almost always Surrey. alone. Its haunts are similar to those of FULLING, the art or act of cleansing, the common water-hen. Its nest is built in scouring, and pressing cloths, stuffs, and the form of a boat, and tied or fixed to stockings, to render them stronger, closer, reeds to prevent its being carried off by the and firmer; called also milling. The fulling water. Its young run as soon as they are of cloths and other stuffs is performed by a hatched. For the great coot, see Aves, kind of water-mill, thence called a fulling Plate VII, fig. 4.
or scouring. mill. These mills, except in FULIGO, in botany, a genus of the what relates to the mill-stones and hopper, Cryptogamia Fungi class and order. Fungus are much the same with corn-mills: and with a cellular fibrous bark; the fibres pe there are even some which serve indiffe. netrating in a reticulate manner through rently for either use ; corn being ground, the seminal mass.
and cloths fulled, by the motion of the same FULLER, a workman employed in the wheel. Whence in some places, particuwoollen manufactories, to mill, or scour, larly in France, the fullers are called milcloths, serges, and other stuffs, in order to lers ; as grinding corn and milling stuffs at render them more thick, compact, and the same time. The method of fulling durable.
cloths and woollen stuffs with soap is this : FULLER's earth, in natural history, a soft, a coloured cloth is to be laid in the usual greyish, brown, dense, and heavy marle : manner in the trough of a fulling mill, withwhen dry, it is of a greyish, ash-coloured out first soaking it in water, as is commonly brown, in all degrees from very pale to al practised in many places. To full this most black, and it has generally something trough of cloth, 15 pounds of soap are reof a greenish cast: it is very hard and firm, quired, one half of which is to be melted in of a compact texture, of a rough and some two pails of river or spring water, made as what dusty surface, that adheres slightly to hot as the hand can well bear it. This sothe tongue : it is very soft to the touch, lution is to be poured by little and little not staining the hands, nor breaking easily upon the cloth, in proportion as it is laid in between the fingers: it has a little harsh. the trough ; and thus it is to be fulled for at ness between the teeth, and melts freely least two hours ; after which it is to be in the mouth : thrown into water, it makes taken out and stretched. This done, the no' ebullition, or hissing, but swells gra, cloth is immediately returned into the same
- trongh, without any new soap, and then fulled pletely succeeded in stopping the progress two hours more. Then taking it out, they of the rot among sheep: it has destroyed wring it well, to express all the grease and the putrid odours arising from meat in the filth. After the second fulling, the remain worst possible state, as well as having been der of the soap is dissolved as in the former, eminently successful in the care of the and cast four different times on the cloth, most alarming fevers, and preventing the remembering to take out the cloth every effects of contagion. two bours to stretch it, and undo the plaits FUNARIA, in botany, a genus of the and wrinkles it has acquired in the trough. Cryptogamia Musci class and order. CapWhen they perceive it sufficiently fulled, sule obovate; fringe double; outer, of 16 and brought to the quality and thickness oblique wedge-form teeth, cohering at the required, they scour it in water, keeping it tips; inner, a membrane divided into 16 in the trough till it is quite clean. As to flat teeth ; veil square. There are three white cloths, as these full more easily and in species. less time than coloured ones, a third part of FUNCTION, in algebra, denotes any the soap may be spared.
compound quantity; and when one of the FULMINATION, in chemistry, differs component quantities is variable it is said from detonation only in degree, they are to be a variable function. both the effects of rapid decomposition
Functions are formed either by addition, accompanied by a loud noise, either with or subtraction, multiplication, division, involuwithout flame. See Golv, MERCURY, tion, or evolution; as also by the resolution POWDER, Silver.
of equations. But besides these, which FUMARIA, in botany, English fumitory, are called algebraical functions, there are a genus of the Diadelphia Hexandria class others called transcendental, arising from and order. Natural order of Corydales. the management of exponents, logarithms, Papaveraceæ, Jussieu. Essential character: &c. calyx two-leaved; corolla ringent ; fila FUNDS, public, the taxes or other pabments two, membranaceous, with three an- lic revenues appropriated to the payment thers on each. There are fifteen species. of the interest or principal of the national
FUMIGATION, in medicine, a process debt. When the expedient of borrowing by means of wbich the nitrous and other large sums for the public service was first mineral acids, in a state of vapour, is dis- adopted, it was found necessary to set persed through the apartments of those who apart and assign to the lender the produce lie sick of infectious fevers. This method of some branch of the revenue supposed to of destroying contagion, in crowded places, be adequate to the payment of the interest was first brought into practice by Dr. or principal, or both, according to the Carmichael Smyth, who having given some terms of the contract ; each loan had thus striking proofs of its efficacy received a a separate fund provided for it, which was reward from parliament. When this fumi- usually distinguished by the date of the gation is undertaken on board ships, the transaction, the rate per cent. payable, or ports and scuttles are closed, a number of some circumstance relating to the mode of pipkins, containing hot sand, are procured, raising the money or the purpose to which and into each is plunged a small tea-cup, it was to be applied. These separate funds containing balf an ounce of sulphuric acid. sometimes produced more than the yearly As soon as the acid is properly heated an payments with which they were charged, equal quantity of pulverised nitre is added, but more frequently fell short of them, and and the mixture stirred with a glass rod. as making good the deficiencies of some, The vapour resulting from the decomposition from the surpluses of others, or from the of nitre ascends, and is by the nurses con current supplies, created much trouble and ducted to every part of the apartment; useless intricacy in the management of the which not only abates the malignity of the public finances, it was found inore convefever, but effectually stops the progress of nient to combine several of the funds, infection. In a late volume of the “ Annales and to charge the payments for which they de Chemie,” we have some striking facts of had been set apart on the aggregate prothe efficacy of fumigation, according to the duce of the several duties. It then became method of M. Guyton de Morveau, who necessary to give a more general denomina. makes use of sulphuric acid, sea-salt, and tion to the fund; and thus have been esta. manganese. It has been tried, and com- blished, at different periods, the Aggregate