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common flute. It is stopped at the upper end, and furnished with moveable brass or silver keys, which, by opening and closing certain holes, serve to temper the tones to the various flats and sharps. In playing this instrument the performer applies his under lip to a hole about two inches and a half from the upper extremity, while the fingers, by their action on the holes and keys, accommodate the tones to the notes of the composition.

FLUTES, or FLUTINGS, in architecture, channels or cavities running perpendicularly along the shaft of a column or pilaster. They are chiefly affected in the Ionic order, in which they had their first rise; though they are also used in all the richer orders, as the Corinthian or Composite; but rarely in the Doric; and scarce ever in the Tuscan. Their number is usually twenty-four, though in the Doric it is only twenty. Each flute is hollowed exactly in a quadrant of a circle. Between the flutes are little spaces that separate them, called by Vitruvius, strice, and by us, lists; though in the Doric, the flutes are frequently made to join each other, without any intermediate space at all, the list being sharpened off to a thin edge, which forms a part of each flute.

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FLUVIATICK. a. (fluviaticus, Latin.) Belonging to rivers.


FLUX, s. (fluxus, Latin.) 1. The act of flowing; passage (Digby). 2. The state of passing away and giving place to others (Bro.). 3. Any flow or issue of matter (Arbuthnot). 4. Dysentery disease in which the bowels are excoriated and bleed; bloody flux (Hali fax). 5. Excrement; that which falls from bodies (Shakspeare). 6. Concourse; confluence (Shakspeare). 7. The state of being melted. 8. That which mingled with the body makes it melt.



FLUX (fluss, Gernian), in chemistry, any substance which is added to another to assist its fusion when heat is applied. Thus alkali is a flux for flint, as when mixed with it in due proportion, and heated, it causes it to melt into the compound called glass.

The term flux is almost exclusively, in che

mistry, applied to those substances, often saline mixtures, that are added to minerals or metallic ores to assist in the process of reduction.

White fur is made simply by mixing equal parts of tartar or cream of tartar and nitre, and deflagrating them in a clean crucible. The nitrous acid burns the carbonaceous part of the tartar, and the mixed alkalies of the nitre and tartar alone remain. This flux is, there. fore, little else than a pure subcarbonat of potash. The mixture of these substances before deflagration is called crude flux. But of all the saline reducing substances that most frequently employed is black flux. This is made by deflagrating in a large crucible a mixture of one part of nitre and two of tartar; and differs from the former in containing, besides carbonat of potash, a quantity of charcoal of the tartar, which there has not been nitre enough to consume. It therefore both assists in the fusion of ores by its alkaline ingredient, and oxygenates, and reduces them to the metallic state by means of its carbon.

In making this last flux, the materials, previously well mixed, should be thrown by small quantities into a red-hot crucible, and loosely covered after each projection; and as soon as the last portion is deflagrated, it should be removed from the fire, and kept in well-closed bottles to prevent the deliquescence of the alkali. Bergman however uses the term flux in a much more extensive sense; and intends by it not only substances useful in the reduction of metals, but substances capable of analyzing by the blowpipe saline, earthy, or inflammable matters. The fluxes recomiended by him for this purpose are the following.

1. The phosphoric acid, or rather the microcosmic salt, as it is called, which contains that acid partly saturated with mineral, partly with amnionia, and loaded besides with much water. This salt, when exposed to the flame, boils and foams violently, with a continual crackling noise, until the water and ammonia have flown off: afterwards it is less agitated, sending forth something like black scoria arising from the burned gelatinous part: these, however, are soon dispelled, and exhibit a pellucid sphericle encompassed by a beautiful green cloud, which is occasioned by the de flagration of the phosphorus, arising from the extrication of the acid by means of the inflammable matter. The clear globule which remains, upon the removal of the flame, continues longer soft than that formed by borax, and therefore is more fit for the addition of the matter to be dissolved. The ammonia is expelled by the fire; therefore an excess of acid remains in what is left behind, which readily attracts moisture in a cool place. 2. Soda, when put upon charcoal, melts superficially, penetrates the charcoal with a crackling noise, and then disappears. In the spoon it yields a permanent and pellucid sphericle, as long as it is kept fluid by the blue apex of the flame, but when the heat is diminished, it becomes

paque, and assumes a milky colour. It attacks several earthy matters, particularly those of the siliceous kind, but cannot be employed on charcoal. 3. Crystallized borax, exposed to the flame urged by the blowpipe, or charcoal, first becomes opaque, white, and excessively swelled, with various protuberances, or branches proceeding out from it. When the water is expelled, it easily collects itself into a mass, which, when well fused, yields a transparent sphericle, retaining its transparency even after cooling. If calcined borax be employed, the clear sphericle is obtained the


Having provided every thing necessary, the following directions are next to be attended to. 1. A common tallow candle, not too thick, is generally preferable to a wax candle, or to a lamp. The snuff must not be cut too short, as the wick should bend towards the object. 2. The weaker exterior flame must first be directed upon the object, until its effects are discovered; after which the interior flame must be applied. 3. We must observe with attention whether the matter decrepitates, splits, swells, vegetates, boils, &c. 4. The piece exposed to the flame should scarcely ever exceed the size of a pepper-corn, but ought always to be large enough to be taken up by the forceps. 5. A small piece should be added separately to each of the fluxes; concerning which it must be observed whether it dissolves wholly or only in part; whether this is effected with or without effervescence, quickly or slowly; whether the mass is divided into a powder, or gradually and externally corroded; with what colour the glass is tinged, and whether it becomes opaque or remains pellucid.

Having given these directions, M. Bergman proceeds next to consider the subjects proper to be examined by the blowpipe. These he divides into four classes: 1. Saline; 2. Earthy; 3. Inflammable; and 4. Metallic. As the sub ject, however, is treated at considerable length, we shall refer the reader to M. Bergman's writings, and confine ourselves in this place to what he has advanced concerning the last of these subjects, namely, metallic substances.

The perfect metals, when calcined (oxygenated) in the moist way, recover their former nature by simple fusion. The imperfect metals are calcined by fire, especially by the exterior flame; and then, in order to their being reduced, indispensably require the contact of an inflammable substance. With respect to fisibility, the two extremes are mercury and platina; the former being scarcely ever seen in a solid form, and the latter almost as difficult of fusion. The metals, therefore, may be ranked in this order, according to their degrees of fusibility. 1. Mercury; 2. Tin; 3. Bismuth; 4. Lead; 5. Zinc; 6. Antimony; 7. Silver; 8. Gold; 9. Arsenic; 10. Cobalt; 11. Nickel; 12. Irou; 13. Manganese; 14. Platinum. The last two do not yield to the blowpipe, and indeed forged iron does not melt without difficulty; but cast iron perfectly. Metals in fusion affect a globuluar form, and

easily roll off the charcoal, especially when of the size of a grain of pepper. Smaller pieces, therefore, ought either to be used, or they should rest in hollows made in the charcoal. On their first melting they assume a polished surface, an appearance always retained by the perfect metals; but the imperfect are soon obscured by a pellicle formed of the calx (oxide) of the metal. The colours communicated by the calces vary according to the nature of the metal from which the calx is produced. Some of the calces easily recover their metallic form by simple exposure to flame upon the charcoal; others are reduced in this way with more difficulty; and some not at all. The reduced calces of the volatile metals immediately fly off from the charcoal. In the spoon they exhibit globules; but it is very difficult to prevent them from being first dissipated by the blast.

The metals are taken up by the fluxes; but as soda yields an opaque spherule, it is not to be made use of. Globules of borax dissolve and melt any metallic calx; and, unless too much loaded with it, appear pellucid and coloured. A piece of metal calcined in flux produces the same effect, but more slowly. A portion of the calx generally recovers its metallic form, and floats on the melted matter like one or more excrescences.

The calces of the perfect metals are reduced by borax in the spoon, and adhere to it at the point of contact, and there only. The microcosmic salt acts like borax, but does not reduce the metals. It attacks them more powerfully on account of its acid nature; at the same time it preserves the spherical form, and therefore is adapted in a peculiar manner to the investiga

tion of metals.

The tinge communicated to the flux frequently varies, being different in the fused and in the cooled globule; for some of the dissolved calces, while fused, show no colour, but acquire one while cooling; but others, on the contrary, have a much more intense colour while in the state of fluidity. Should the transparency be injured by too great a concentration of colour, the globule, on compressing it with the forceps, or drawing it out into a thread, will exhibit a thin and transparent mass; but if the opacity arises from supersaturation, more flux must be added; and as the fluxes attract the metals with unequal forces, the latter precipitate one another.

Metals when mineralized by acids have the properties of metallic salts; when mineralized by carbonic acid, they possess the properties of calces, that volatile substance being easily expelled without any effervescence; but when combined with sulphur they possess properties of a peculiar kind. They may then be melted, or even calcined upon the charcoal, as also in a golden or silver spoon. The volatile parts are distinguished by the smell or smoke; the fixed residua, by the particles reduced or precipitated upon iron, or from the tinge of the fluxes.

Gold in its metallic state fuses on the charcoal, and is the only metal which remains un

changed. It may be oxygenated in the moist way by solution in aqua regia; but to calcine it also by fire, we must pursue the following method: To a globule of microcosmic salt, let there be added a small piece of solid gold, of gold leaf, purple mineral, or, which is best of all, of the crystalline salt formed by a solution of gold in aqua regia containing sea-salt. Let this again be melted, and added while yet soft to turbith mineral, which will immediately grow red on the contact. The fusion being afterwards repeated, a vehement effervescence arises; and when this is considerably diminish ed, let the blast be stopped for a few moments, again begun, and so continued until almost all the bubbles disappear. After this the spherule, on cooling, assumes a ruby colour; but if this does not happen, let it be just made soft by the exterior flame, and upon hardening, this tinge generally appears. Should the process fail at first, owing to some minute circumstances which cannot be described, it will succeed on the second or third trial. The rubycoloured globule, when compressed by the for. ceps while hot, frequently becomes blue; by sudden fusion i. generally assumes an opal colour, which by refraction appears blue, and by reflection of a brown red. If further urged by the fire it loses all colour, and appears like water; but the redness may be reproduced several times by the addition of turbith mineral. The flux is reddened in the same manner by the addition of tin instead of turbith; but it has a yellowish hue, and more easily becomes opaque; while the redness communicated by turbith mineral has a purple tinge, and quite resembles a ruby. Borax produces the same phenomena, but more rarely; and in all cases the slightest variation in the management of the fire will make the experiment fail entirely. The ruby colour may also be produced by copper; whence a doubt may arise, whether it is the gold or the remains of the copper that produce this effect. M. Bergman thinks it probable that both may contribute towards it, especially as copper is often found to contain gold.

This precious metal cannot directly be mineralized by sulphur: but by the medium of iron is sometimes formed into a golden pyrites. Here, however, the quantity of gold is so small, that a globule can scarcely be extracted from it by the blowpipe.

Grains of native platinum are not affected by the blowpipe, either alone or mixed with fluxes; which, however, are frequently tinged green by it: but platinum, precipitated from aqua regia by vegetable or volatile alkali, is reduced by microcosmic salt to a small malleable globule. Our author has been able to unite seven or eight of these into a malleable mass; but more of them produced only a brittle one. Platinum scarcely loses all its iron, unless reduced to very thin fusion.

Silver in its metallic state easily melts, and resists calcination. Silver leaf fastened by means of the breath, or a solution of borax, may easily be fixed on it by the flame, and

through the glass it appears of a gold colour; but care must be taken not to crack the glass. Calcined silver precipitated from nitrous acid by fixed alkali is easily reduced. The microcosmic acid dissolves it speedily and copiously; but on cooling it becomes opaque, and of a whitish yellow, which is also sometimes the case with leaf-silver. Copper is discovered by a green colour, and sometimes by that of a ruby, unless we choose rather to inpute that to gold. The globules can scarcely be obtained pellucid, unless the quantity of calx is very small; but a longer fusion is necessary to produce an opacity with borax. The globule, loaded with dissolved silver during the time of its fusion in the spoon, covers a piece of copper with silver, and becomes itself of a pellucid green: autimony quickly takes away the milky opacity of dissolved luna cornea, and separates the silver in distinct grains. Cobalt, and most of the other metals, likewise, precipitate silver on the same principles as in the moist way, viz. by a double elective attraction. This metal, when mineralized by marine and vitriolic acids, yields a natural luna cornea, which produces a number of small metallic globules on the charcoal: it dissolves in microcosmic salt, and renders it opaque, and is reduced, partially at least, by borax. Sulphurated silver, called also the glassy ore of that metal, fused upon charcoal, easily parts with the sulphur it contains so that a polished globule is often produced, which, if necessary, may be depurated by borax. The silver may also be precipitated by the addition of copper, iron, or manganese. When arsenic makes part of the compound, as in the red ore of arsenic, it must first be freed from the sulphur by gentle roasting, and finally entirely depurated by borax. It decrepitates in the fire at first.

Copper, together with sulphur and arsenic. mixed with silver, called the white ore of silver, yields a regulus having the same alloy.

Galena, which is an ore of lead containing sulphur and silver, is to be freed in the same manner from the sulphur; after which the lead is gradually dissipated by alternately melting and cooling, or is separated in a cupel from the galena by means of the flame. Bergman has not been able to precipitate the silver distinct from the lead, but the whole mass becomes malleable; and the same is true of tin, but the mass becomes more brittle.

Pure mercury flies off from the charcoal with a moderate heat, the fixed heterogeneous matters remaining behind. When calcined, it is easily reduced and dissipated, and the fluxes take it up with effervescence; but it is soon totally driven off. When mineralized by sulphur, it liquefies upon the charcoal, burts with a blue flame, smokes, and gradually disappears; but, on exposing cinnabor to the fire on a polished piece of copper, the mercurial globules are fixed upon it all round.

Lead in its metallic state readily melts, and continues to retain a metallic splendour for some time. By a more intense heat it boils and smokes, forming a yellow circle upon the

charcoal. It communicates a yellow colour, scarcely visible, to the fluxes; and when the quantity is large, the globule, on cooling, contracts more or less of a white opacity. It is not precipitated by copper when dissolved; nor do the metals precipitate it from sulphur in the same order as from the acids. When united to carbonic acid, it grows red on the first touch of the flame; when the heat is increased it melts, and is reduced to a multitude of small globules. When united with phosphoric acid it melts, and yields an opaque globule, but is not reduced. With Aluxes it shows the same appearance as oxide of lead. When mineralized by sulphur, lead easily liquefies, and being gradually deprived of the volatile part, yields a distinct regulus, unless too much loaded with iron. It may be precipitated by iron and copper.

A small piece of copper, either solid or foliated, sometimes communicates a ruby colour to fluxes, especially when assisted by tin or turbith mineral. If the copper is a little more or further calcined, it produces a green pellucid globule, the tinge of which grows weaker by cooling, and even verges towards a blue. By long fusion with borax, the colour is totally destroyed upon charcoal, but scarcely in the spoon. When once destroyed, this colour can scarcely be reproduced by nitre; but it remains fixed with microcosinic salt. If the calx or metal to be calcined is added in considerable quantity during fusion, it acquires an opaque red on cooling, though it appears green while pellucid and fused; but by a still larger quantity it contracts an opacity even while in fusion, and upon cooling a metallic splendour. Even when the quantity of copper is so small as scarcely to linge the flux, a visible pellicle is precipitated upon a piece of polished iron added to it during strong fusion, and the globule in its turn takes the colour of polished iron; and in this way the smallest portions of copper may be discovered. The globule made green by copper, when fused in the spoon with a small portion of tin, yields a spherule of the latter mixed with copper, very hard and brit tle: in this case the precipitated metal pervades the whole of the mass, and does not adhere to the surface. Cobalt precipitates the calx of copper dissolved in the spoon by a flux, in a metallic form, and imparts its own colour to glass, which nickel cannot do. Zinc alo precipitates it separately, and rarely upon its own surface, as we can scarcely avoid melting it. When mineralized by the carbonic acid, copper grows black on the first contact of the flame, and melts in the spoon; on the charcoal the lower part, which touches the support, is reduced. With a superabundance of marine acid, it tinges the flame of a beautiful colour; but with a small quantity shows no appearalice of the metal in that way. Thus the beautiful crystals of Saxony, which are cubic, and of a deep green, do not tinge the flame, though they impart a pellucid greeuness to microcosmic salt. An opaque redness is easily

obtained with borax: but M. Bergman could not produce this colour with microcosmic salt. Copper simply sulphurated, when cautiously and gently roasted by the exterior flame, yields at last by fusion a regulus surrounded with a sulphurated crust. The mass roasted with borax separates the regulus more quickly.


present, the piece to be examined must first be If a small quantity of iron happens to be roasted, after which it must be dissolved in borax, and tin added to precipitate the copper. The regulus may also be obtained by sufficient calcination and fusion, even without any precipitant, unless the ore is very poor. When the pyrites contain copper, even in the quantity of the one-hundredth part of their weight, its presence may be detected by these experia flax-seed, be roasted, but not so much as to Let a grain of pyrites, of the size of expel all the sulphur; let it then be dissolved by borax, a polished rod of iron added, and the fusion continued until the surface when cooled loses all splendour. As much borax is required as will make the whole of the size of a grain of hemp-seed. Slow fusion is injurious, and the precipitation is also retarded by too great tenuity; but this may be corrected by the addition of a little lime. Too much calcination is also inconvenient; for by this the globule forms slowly, is somewhat spread, becomes knotty when warm, corrodes the charcoal, destroys the iron, and the copper does not precipitate distinctly. This defect is corrected by a small portion of crude ore. When the globule is properly melted, according to the directions already given, it ought to be thrown into cold water immediately on stopping the blast, in order to break it suddenly. If the copper contained in it is less than one-hundredth part, one end of the wire only has a cupreous appearance, but otherwise the whole.

Dr. Gahn has another method of examining the ores of copper, namely, by exposing a grain of the ore, well freed from sulphur by calcination, to the action of the flame driven suddenly upon it by intervals. At those instants a cupreous splendour appears on the surface, which otherwise is black; and this splendour is more quickly produced in proportion as the ore is poorer. The flame is tinged green by cupreous pyrites on roasting.

Forged iron is calcined, but can scarcely be melted. It cannot be melted by borax, though it may by microcosmic salt, and then it be comes brittle. Calcined iron becomes magne tie by being heated on the charcoal, but melts in the spoon. The fluxes become green by this metal; but in proportion as the oxygen is more abundant, they grow more of a brownish yellow. On cooling, the tinge is much weakened, and when originally weak, vanishes entirely. By too much saturation the globule becomes black and opaque. The sulphureous pyrites may be collected into a globule by fu sion, and is first surrounded by a blue flame; but as the metal is easily calcined, and changes

into black scoriæ, neither by itself nor with fluxes does it exhibit a regulus. It grows red on roasting.

Tin easily melts before the blow-pipe, and is calcined. The fluxes dissolve the calx sparingly; and when saturated, contract a milky opacity. Some small particles of this metal dissolved in any flux may be distinctly precipitated upon iron. Crystallized ore of tin, urged by fire upon the charcoal, yields its metal in a reguline state.

Bismuth presents nearly the same appearances of lead; the calx is reduced on the coal, and fused in the spoon. The calx, dissolved in microcosmic salt, yields a brownish yellow globule, which grows more pale upon cooling, at the same time losing some of its transparency. Too much calx renders the matter perfectly opaque. Borax produces a similar mass in the spoon, but on the coal a grey one, which can scarcely be freed from bubbles. On fusion the glass smokes, and forms a cloud about it. Bismuth is easily precipitated by copper and iron. Sulphurated bismuth is easily fused, exhibiting a blue flame and sulphureous smell. Cobalt, when added, by means of sul. phur, enters the globule; but the scoria soon swells into distinct partitions; which, when further urged by fire, throw out globules of bismuth. Sulphurated bismuth, by the addition of borax, may be distinctly precipitated by iron or manganese.

Regulus of nickel when melted is calcined, but more slowly than other metals. The calx imparts an hyacinthine colour to fluxes, which grows yellow on cooling, and by long-continued fire may be destroyed. If the calx of nickel is contaminated by ochre of iron, the latter is first dissolved. Nickel dissolved is precipitated on iron, or even on copper; an evident proof that it does not originate from either of these metals. Sulphurated nickel is nowhere found without iron and arsenic; the regulus is obtained by roasting, and fusing with borax, though it still remains mixed with some other metals.

Regulus of arsenic takes fire by a sudden heat, and not only deposits a white smoke on charcoal, but diffuses the same all around. The calx smokes with the smell of garlic, but does not burn. The fluxes grow yellow with out growing opaque, on adding a proper quantity of calx, which is dispelled by a long continuance of the heat. This semimetal is precipitated in a metallic form by iron and copper, but not by gold. Yellow arsenic liquefies, smokes, and totally evaporates; when heated by the external flame, so as neither to liquefy nor smoke, it grows red, and yellow again upon cooling. When it only begins to melt, it acquires a red colour, which remains after cooling. Realgar liquefies more easily, and is besides totally dissipated.

Regulus of cobalt melts, and may partly be depurated by borax, as the iron is first calcined and taken up. The smallest portion of the lx tinges the flux of a deep-blue colour,

which appears of a violet by refraction, and this colour is very fixed in the fire. Cobalt is precipitated upon iron from the blue globule, but not upon copper. When calx of iron is mixed with that of cobalt in a flux, the former is dissolved. This semimetal takes up about one-third of its weight of sulphur in fusion, after which it can hardly be melted again. It is precipitated by iron, copper, and several other metals. The common ore yields an impure regulus by roasting. The green cobalt, examined by our author, tinges the microcosmic silt blue; but at the same time shows red spots indicating copper.

Zinc exposed to the blow-pipe melts, takes fire, sending forth a beautiful bluish-green flame, which, however, is soon extinguished by a lanuginous calx: but if the reguline nucleous included in this lanuginous matier (commonly called flowers of zinc) is urged by the flame, it will be now and then inflamed, and, as it were explode and fly about. With borax it froths, and at first tinges the flame. It continually diminishes, and the flux spreads upon the charcoal; but in fused microcosmic salt, it not only froths, but sends forth flashes with a crackling noise. Too great heat makes it explode with the emission of ignited particles. The white calx, or flowers, exposed to the flame on charcoal, becomes yellowish, and has a kind of splendour which vanishes when the Alame ceases. It remains fixed, and cannot be melted. The fluxes are scarcely tinged, but when saturated by fusion, they grow opaque and white on cooling. Clouds are formed round the globules, of a nature similar to those of the metallic calx. Dissolved zinc is not precipitated by any other metal. When mineralized by carbonic acid gass, it has the same properties as calcined zinc In the pseudogalena sulphur and iron are present. These generally, on the charcoal smell of sulphur, melt and tinge the flame more or les-, depositing a cloud all around. Those which have no matrix are tinged by those which contain iron, and acquire by saturation a white opaque colour, verging to brown or black, according to the variety of composition.

Regulus of antimony, fused and ignited on the charcoal, affords a beautiful object; for if the blast of air be suddenly stopped, a thick white smoke rises perpendicularly, while the lower part round the globule is condensed into crystalline spiculæ, similar to those called argentine flowers. The calx tinges fluxes of an hyacinthine colour; but on fusion smokes, and is easily dissipated, especially on the charcoal, though it also deposits a cloud on it. The dissolved metal may be precipitated by iron and copper, but not by gold. Crude antimony liquefies on the charcoal, spreads, smokes, penetrates it, and at last disappears entirely, except a ring which it leaves behind.

Regulus of manganese scarcely yields to the flame. The black calx tinges the fluxes of a bluish colour; borax, unless saturated, communicates more of a yellow colour. The co

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