FLU

451

FLU

For this purpose two plates of iron are to be prepared of the sizeof a large bait-sheet of paper, or larger, for particular occasions:these plates must be made so thick as not to bend ; and there mustbe a hole near every corner for a screw to fasten them close to-gether. When these are prepared, lay in readiness several sheetsof paper, and then gather the plants with their llowers when quiteperfect. Let this be always done in the middle of a dry day ; andthen lay the plant and its flower on one of the sheets of paperdoubled in half, spreading out all the leaves and petals as nicely aspossible. If the stalk is thick, it must be pared or cut in half, sothat it may lie flat; and if it is woody, it may be peeled, and onlythe bark left. When the plant is thus expanded, lay round about itsome loose leaves and petals of the flower, which may serve tocomplete any part that is deficient. When all is thus prepared,lay several sheets of paper over the plant, and as many under it;then put the whole between the iron plates, laying the paperssmoothly on one, and laying the other evenly over them: screwthem close, and pnt them into an oven after the bread is drawn,and let them lie there two hours. After that, make a mixture ofequal parts of aquafortis and brandy; shake these well together,and when the flowers are taken out of the plates, rub them lightlyover with a camel’s-hair pencil dipped in this liquor; then laythem upon fresh brown paper, and covering them with some othersheets, press them between this and other papers with a handker-chief till the wet of these liquors is dried wholly away. \\ hen theplant is thus far prepared, take the bulk of a nutmeg of gum-dra-gon; put this into a pint of pure water cold, and let it stand 24nours; it will in this time be wholly dissolved: then dip a tine hairpencil in this liquor, and with it daub over the back sides of theleaves, and lay them carefully down on a halt-sheet of whitePaper fairly (expanded, and press them down with some morePapers over these. When the gum-water is fixed, let the pressure3nd papers be removed, and the whole work is finished. Theleaves retain their verdure in this case, and the flowers usuallykeep their natural colours. Some care, however, must be taken,that the heat of the oven be not too great. When the flow ers arethick and bulky, some art may be used to pare off their backs,and dispose the petals in due order; and after this, if any of themare wanting, their places may be supplied with some of the super-numerary ones dried on purpose; and if any of them are only-faded, it will be prudent to take them away, and lay down othersiu their stead: the leaves may be also disposed and mended in thesame manner. III. Another method of preserving both flowersand fruit sound throughout the whole year, is also given by the-same author. Take saltpetre one pound, Armenian bole twopounds, clean common sand three pounds. Mix all well together;then gather fruit of any kind that is not fully ripe, with the stalk toeach; put these in, one by one, into a wide-mouthed glass, laytug them in good order. Tie over the top with an oil cloth, andCarry them into a dry cellar, and set the whole upon a bed of thePrepared matter, of two inches thick, in a box. Fill up the re-mainder of the box with the same preparation; and let it be fourmches thick ail over the (op of the glass, and all round its sides,flowers are to be preserved in the same sort of glasses, and in thesame manner; and they may be taken up after a whole year asplump and fair as when they were buried.

. Flowers, in chemistry, generally imply dry bodies reducedinto very tine parts, either spontaneously, or by some operation°‘ art; but the term is chiefly applied to volatile solid substances,reduced into a kind of fine meal by sublimation. Some flowersare nothing else than the bodies themselves, which are sublimedentire, without suffering any alteration or decomposition ; othersare some of the constituent parts of the body subjected to sublinia-

I' lowers, in heraldry. They are much used in coats of arms;and i n general signify hope, or denote human frailty and monien-tar y prosperity.

r lowers, in rhetoric, [ Jlosculi ., Lnt.] figures or ornaments ofan i?J ia R f '- See Comparison, Figure, Oratory, &c.

“■OWN SHEETS, in the sea language, a ship is said to sail

'til flown sheets when her sails are not haled home, or close to

e a'°eks. The sheets are flown; that is, they are let loose, orn »> as far as they will

are

o l f-S, in chemistry, salts first discovered by Scheele ; theydistinguished by the following properties: 1. When sulphuric

prope

acid is poured upon them, they emit acrid vapours of fluoric acid,which.corrode glass. 2. When heated, several of them phospho-resce. 3. They are not decomposed by heat, nor altered by com-bustibles. 4, They combine with silica by means of heat. Mostof them are sparingly soluble in water.

Fluatf, of Lime, Fluor Spar. This mineral is found abund-antly in different countries, particularly in Derbyshire . It is bothamorphous and crystallised. The primitive form of the crystals isthe regular octahedron ; that of its integrant molecules the regulartetrahedron. The varieties of its crystals hitherto observed amountto nine. These are the primitive octahedron; the cube; therhomboidal dodecahedron ; the cubo-octahedron, which has boththe faces of the cube and of the octahedron : the octahedron want-ing the edges; the cube wanting the edges, and either one face ortwo faces in place of each. According to Pelletier, it is com-posed of

21 lime15 alumina31 silica28 fluoric acidt phosphoric acid1 muriatic acid1 oxide of iron •

1 water

99

FLUELLIN, the herb Speedwell. See Antirrhinum .

FLUENT, i» fluxions, the flowing quantity, or that which iscontinually either increasing, or decreasing, whether line, surface,solid, &c. See Fluxion.

FLUID, in physics, is a term applied to all bodies whose par-ticles easily yield to the least partial pressure, or force impressed.See Fluidity and Hydrostatics.

Fluid, in physiology, an appellation given to all bodies whoseparticles easily yield to the least partial pressure, or force impress-ed. See Hydrostatics, and the next article.

FLUlDPI'Y, is that state or affection of bodies in which theirparts easily move one among another. All substances in nature,as far as we are acquainted with them, occur in one or other of thethree following stales; namely, the state of solid::, of liquids, or ofelastic fluids or vapours. It has been ascertained, that in a vastnumber of cases, the same substance is capable of existing succes-sively in each of these state's. Thus sulphur is usually a solidbody ; but when heated to 212° it is converted into a liquid; andat a still higher temperature (about 570“), it assumes the term of anelastic vapour of a deep-brown colour. Water also in our climateis usually a liquid ; but when cooled down to 32° it is convertedinto a solid body, and at 212° it assumes the form of an elastic fluid.Most solid bodies may be converted into liquids by heating themsufficiently, and on the other hand, every liquid, except spirit ofwine, is convertible into a solid body, by exposing it to a suffi-cient degree of cold. All liquid bodies may, by beating them,be converted into elastic fluids, and a great many solids are ca-pable of undergoing the same change; and, lastly, the number ofelastic fluids which by cold are condensable into liquids or solids,is by no means inconsiderable. These facts have led philosophersto form this general conclusion, “ that all bodies, if placed in atemperature sufficiently low, would assume a solid form ; that allsolids become liquids when sufficiently healed; and that all liquids,when exposed to a certain temperature, assume the form of elasticfluids.” The state of bodies then depends upon the temperaturein which they are placed; in the lowest temperatures they are allsolid, in higher temperatures they are converted into liquids, andin the highest of all they become elastic fluids. The particulartemperatures at which bodies undergo those changes are ex-ceedingly various, but they are always constant for the same bo ~| dies. Thus we see that heat produces changes on the state ofi bodies, converting them all, first Into liquids, and then elasticfluids.

1. When solid bodies ate converted by heat into liquids, thechange in some cases takes place at once. There is no intervalbetween solidity and liquidity ; but in other cases a very gradualchange maybe perceived; the solid becomes first soft, auditpasses slowly through all the degrees of softness, till at last it be-comes perfectly fluid. The conversion of ice into water is an in-stance