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Flesh, the muscular part of an animal body, in which the blood vessels are so small as to retain only blood enough to give them a red colour.

FLINT, in natural history, a semi-pellucid stone, composed of crystal debased with earth, of one uniform substance, and free from veiņs; but of different degrees of colour, according to the quantity of earth it contains, and naturally surrounded with a whitish crust. Flint is a stone of an extremely fine, compact, and firm texture, and very various, both in size and figure. It is of all the degrees of

grey, from nearly quite black, to almost quite wbite. It breaks with a fine, even glossy surface; and is moderately transparent, very hard, and capable of a fine polish. It readily strikes fire with steel, makes not the least effervescence with aquafortis, and burns to whiteness. Its uses in glass making are well known.

It is not uncommon to find on the shores fine, pellucid, flinty bodies, streaked or veined with white, bļack, brown, &c. These are the agates of Britain, answering in every particular, but fineness,

to the gem.

The manner of preparing flints, for the nicer operations in the glass-trade, is this : after they are freed from the white crusts with which they are commonly surrounded, they are calcined in a strong fire, and then powdered in an iron mostar, the powder being sifted through a very fine sieve; on this powder some weak aquafortis is poured, to dissolve any particles of iron it may have imbibed from the mortar ; then, after standing some time, it is washed with hot-water, and dried for use.

Float-boards, those boards fixed to water-wheels

of under shot mills, serving to receive the impulse of the stream, by which the wheel is carried round. See MILL.

Flood, among seainen, is when the tide begins to come up, or the water begins to rise, then they call it young flood ; after which it is a quarter flood, half flood, and high flood.

FLOTA, a name which the Spaniards give particularly to the ships that are annually sent from Cadiz to the port of Vera Cruz, to fetch thenee the merchandizes gathered in Mexico for Spain. This fleet consists of the captains, admiral, and patach or pinnace, which goes on the king's ac. count, and about sixteen ships, from four hundred to a thousand tons, belonging to particular persons. They set out from Cadiz about the month of Au. gust, and make it about eighteen or twenty months before they return.

FLOTILLA, a name given to a number of ships which get before the rest in their return, and give information of the departure and cargo of the flota and galleons. See the preceding article.

Flour, the meal of corn, finely ground and sifted. The grain itself is not only subject to be eaten by insects in that state, but when ground into flour it gives birth to another race of destroyers, who increase so fast, that it is not long before they wholly destroy the substance. The finest flour is most liable to breed these, especially when stale. Flour, when carefully analyzed, is found to consist (1) of fæcula, which is insoluble in cold water: (?) of gluten : (3) of a saccharine matter, susceptible of spirituous fermentation.

Flower, in Botany, that beautiful vegetable pro

duetion which surrounds, nourishes, and fertilizes the seed or fruit in its earliest state.

Flowers, in chemistry, a term formerly applied to a variety of substances procured by sublimation, and were in the form of slightly colouring powder : hence, in all old books, we find mention made of the flowers of antimony, arsenic, zinc, and bismuth, which are the sublimed oxides of these metals, eiiher pure, or combined with a small quantity of sulphur: we have also still in use, though not generally, the terms flowers of sulphur, benzoin, &c.

FLUATES, in chemistry, salts of which the Fluoric acid (which see) is the chief ingredient, Fluor spar, denominated fluate of lime, which is found in great plenty in many countries, and is very

abun. dant in Derbyshire, where it obtains the name of Derbyshire spar, is the most important among the fuates. The chief properties of these salts are, 1. When sulphuric acid is poured upon them, they emit acrid vapours of fuoric acid, which corrode glass. 2. When heated, several of them phosphoresce. 3. They are not decomposed by beat, nor altered by combustibles. 4. They combine with silica by means of heat.

Fluid, in physiology, an appellation given to all bodies whose particles easily yield to the least par. tjal pressure, or force impressed.

The nature of a fluid, as distinguished from that of a solid, or hard body, consists in this, that its particles are so loosely copnected together, that they readily move out of their places, when pressed with the least force one way more than another; whence philosophers have concluded, that these particles are exceedingly minute, smooth, and round,

it being otherwise impossible they should move with such freedom upon the least inequality of pressure.

Those particles, considered separately, are endowed with all the common properties of matter, and are subject to the same laws of motion and gravitation with larger bodies. To inquire, therefore, into the nature of Aluids, is to consider what appearances a collection of

very

small round bodies, subject to these laws, will exhibit under different circumstances.

Fluids, motion of. The motion of fluids, viz. their descent or rise below or above the common surface or level of the source or fountain, is caused either, 1. By the natural gravity or pressure of the fluid contained in the reservoir, or fountain ; 'or, 2. By the pressure or weight of the air on the surface of the fluid in the reservoir, when it is at the same time either taken off or diminished on some part in aqueducts, or pipes of conduit. 3. By the spring or elastic power of compressed or condensed air, as in the common water engine. 4. By the force of pistons, as in all kinds of forcing pumps, &c. 5. By the power of attraction, as in the case of tides, &c.

Fluor spar, the native fluate of lime, from whence is obtained

Fluoric acid : the most remarkable property of this acid, is the facility with which it corrodes glass and all siliceous bodies, especially when hot, and the ease with which it holds silica in solution, even when in a state of gas. Hence this acid has been applied to etching on glass vessels.

FLUTE, an instrument of music, the simplest of

all those of the wind kind. It is played on by blowing it with the mouth, and the tones or notes are changed by stopping and opening the holes disposed for that purpose along its side. The antient fistulæ, or flutes, were made of reeds, after. wards of wood, and lastly of metal : but how they were blown, whether as our flutes, or as hautboys, does not appear.

It is plain some had holes, which, at first, were but few, but afterwards increased to a great number, and some had none; some had single pipes, and some a combination of many, particularly Pan's syringa, which consisted of seven reeds joined together sidewise.

Flute, German, an instrument entirely different from the comman-flute. It is not, like that, put into the mouth to be played, but the end is stopped, with a tampion, or plug; and the lower lip is applied to a hole about two inches and a half, or three inches, distant from the end. This instrument is usually about a foot and a half long ; rather bigger at the upper end than the lower; and perforated with holes, besides that for the mouth, the lowest of which is stopped and opened by the little finger pressing on a brass, or sometimes a silver key, like those in hautboys, bassoons, &c. Its sound is exceedingly sweet and agreeable; and serves as a tree ble in a concert.

FLUTES or flutings, in architecture, perpendicular channels, or cavities, cut along the shaft of a column, or pilaster. They are chiefly effected in the Ionic order, where they had their first rise; though, indeed, they are used all in the richer orders, as the Corinthian and Composite; but seldom in the Doric,

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