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there sessile, sitting on the tips of the petals; follicle round. There are four species.

EMBRACERY, is an attempt to corrupt or influence a jury, or any way incline them to be more favourable to the one side than the other, by money, promises, letters, threats, or persuasions; whether the juror, on whom such attempt is made, give verdict or not, or whether the verdict given be true or false, which is punished by fine and imprisonment; and the juror taking money, perpetual infamy, impri-onment for a year, and forfeiture of teufol- the value.

EMBRASURE, in fortification, a hole or aperture in a parapet, through which the cannon are pointed to fire into the moat or field. Embrasures are generally twelve feet distant from one another, every, one of them being from six to seven feet wide without, and about three within: their height above the platform is three feet on that side towards the town, and a foot and a half on the other side towards the field; so that the muzzle may be sunk on occasion, and the piece brought to shoot low.

EMBROCATION, in surgery, an external kind of remedy, which consists in an irrigation of the part affected with some proper liquor, as oils, spirits, ice. by means of a woollen or linen cloth, or a sponge, dipped in the same. The use of embrocation is either to attenuate and dislodge something obstructed underneath the skin, to ease pains, or to irritate the part into more warmth and a quicker sense of feeling. The pumping used in natural baths is properly an embrocation.

EMBROIDERY, a work in gold, or silver, or silk thread, wrought by the needle upon cloth, stuff, or muslin, into various figures. In embroidering stuffs, the work is performed in a kind of loom, because the more the piece is stretched, the easier it is worked. As to muslin, they spread it upon a pattern ready designed; and sometimes, before it is stretched upon the pattern, it is starched to make it more easy to handle. Embroidery on the loom is less tedious than the other, in which, while they work flowers, all the threads of the muslin, both lengthwise and breadthwise, must be continually countedi but on the other hand, this last is much richer in points, and susceptible of greater variety. Cloths too much milled are scarce susceptible of this ornament, and in effect we seldom see them embroidered. The thinnest muslins are left for this purpose, and they are embroidered to the greatest perfection in Saxony; in

other parts of Europe, however, they embroider very prettily, and especially in France.

There are several kinds of embroidery, as, 1. Embroidery on the stamp, where the figures are raised and rounded, having cotton or parchment put under them to support them. 2. Low embroidery, where the gold and silver lie low upon the sketch, and are stitched with silk of the same colour, 3. Guimped embroidery: this is performed either in gold or silver; they first make a sketch upon the cloth, then put on cut vellum, and afterwards sew on the gold and silver with silk thread: in this kind of embroidery they often put gold and silver cord, tinsel, and spangles. 4. Embroidery on both sides; that which appears on both sides of the stuff. 5. Plain embroidery, where the figures are flat and even, without cords, spangles, or other ornaments.

Embroidery, no foreign embroidery, on gold or silver brocade, is permitted to be imported into this kingdom on pain of being seized and burned, and a penalty of lOOf. for each piece.

EMBRYO, in physiology, the first rudiments of an animal in the womb, before the several members are distinctly formed; after which period it is denominated afcetns. See Fojtl's and Midwifery. Embryo, in botany. See Corculi'm. EMERALD. This mineral comes chiefly from Peru; some specimens have been brought from Egypt. Dolomieu found it in the granite of Elba. Hitherto it has been found only crystallized. The primitive form of its crystals is a regular six-sided prism; and the form of its integrant molecules is a triangular prism, whose sides are squares, and bases equilateral triangles. The most common variety of its crystals is the regular six-sided prism, sometimes with the edges of the prism, or of the bases, or the solid angles, or both wanting, and small faces in their place.

Crystals short; lateral planes smooth, terminal planes rough; colour emerald green of all intensities; internal lustre between 3 and 4; vitreous ; fracture small, imperfect, conchoidal, with a concealed foliated fracture, and fourfold cleavage; fragments sharp-edged; transparency 4 to a; causes double refraction; scratches quartz with difficulty. Specific gravity from 2.600 to 2.7755.

The fossil here described is the occidental emerald, and appears from antique gems to have beer known in the earlier ages, though

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conversation, ami seemingly rode, commonly miviuat oath* in ass sentences, though without any ill intention . he had strong food natural mental parts, and cocld discourw snwbr. on any •uhjsxt, bat was always pontine and impatient of contradiction , he spent his whole hn> in close study, aud writing books trvmi the profits of which he rrsirenKsl hit little patrimony from some original incumbrance; in he dress be was as singular as in every thins: else. be possessed commonly but one snit of doaths at a time, ami those very old in their appearance , he seldom used a waistcoat; and his coat he wore open before, except the lower button; ami his shirt quite the reverse of one in common use, the hind side turned foremost, to cover his breast, and buttoned close at the collar behind; he wore a kind of rusty coloured wis, without a crooked hair in it, which probably had never been tortured with a comb from the time of its being made; a hat he would make to last him the best part of a life-time, gradually lessening the Hups, bit by bit, as it lost its elasticity and hung down, till little or nothing hut the crown remained.

He ol leu walked up to London when he had any book to be published, revising sheet by sheet himself: trusting no eye but Ilia own, was always a favourite maxim with him. In mcclr.iiiic.il subjects, he always tried the propositions practically, making all the different parts himself on a small scale; so that his house was rilled with all kinds of mechanical instruments, together or disjointed. He would frequently stand up to his middle in water while fishing, a diversion he was remarkably fond of. He used to study incessantly tor some time, and then for relaxation take a ramble to any pot ale-house where he could get any body to drink with, and talk to. "Die late Mr. Montague was very kind to Mr. Emerson, and often visited him, being pleased with his conversation, and used frequently to come to him in the fields where he was working, and accompany him home, but could never persuade, him to get into a carriage: on these occasions he would sometimes exclaim, "Damn your whim-wham! I had rather walk." He was a married man, and his wife used to spin on an oldfashioned wheel, of his own making, a drawing of which is given in his "Mechanics."

Mr. Emerson, from his strong, vigorous mind and close application, had acquired deep knowledge of all the branches of mathematics and physics, upon all parts of

which he wrote good treatise*, though in a rough and unpolished style and manner. He was not remarkable, however, for genius or discoveries of his own, as his works hardly shew any traces of original invention. He was well skilled in the science of music, the theory of sounds, and the various scales both ancient and modern; bat he »a< a very poor performer, though he could make and repair some instruments, and sometimes went about the country tuning harpsichords.

The following is the list of Mr. Emerson's works, all of them printed in 8vo., excepting his "Mechanics" and his " Increments," in 4to., and his "Navigation" in 12mo. 1. The Doctrine of Fluxions. 2. The Projection of the Sphere, Orthographic, Stereograpbic, and Gnomonical. 8. The Elements of Trignometry. 4. The Principles of Mechanics. 5. A Treatise of Navigation on the Sea. 6. A Treatise on Arithmetic. 7. A Treatise on Geometry.

8. A Treatise of Algebra, in two books.

9. The Method of Increments. 10. Arithmetic of Infinities, and the Conic Sections, with oilier Curve Lines. 11. Elements of Optics and Perspective. IS. Astronomy. 13. Mechanics, with Centripetal and Centrifugal Forces. 14. Mechanical Principles of Geography, Navigation, and Dialling. 15. Commentary on the Principia, with the Defence of Newton. 16. Tracts. 17. Miscellanies.

EMERY, a stone of the ruby family, of which three kinds are usually distinguished in commerce -, the Spanish, red, and common emery.The first sort is found in the gold mines of Peru, and being judged a kind of marcasitc of that rich metal, is prohibited to be exported. The red emery is fonnd in copper mines, and the little there is of it in England comes from Sweden and Denmark. The common emery is taken opt of iron mines, and almost the only sort used in England; it is of a brownish colour, bordering a little on red, exceedingly bard, and in consequence difficult to pulverize. The English are the only people who have the art of reducing common emery into powder, and thus send it to their neighbours. Of the powder, the most subtile and impalpable is the best: as to the stone, it should be chosen of a high colour, and as free of the rock as possible.

The consumption of emery is very considerable among the armourers, cutlers, locksmiths, lapidaries, masons, and other mechanics; some of whom use it to polish and burnish iron and steel works; others, to

cut and scallop glass, marble, and precious stones.

EMETIC, a medicine which induces vomiting.

Emetic tartar, the old name for tartrite of antimony.

EMOLLIENTS. See Piiahmacy.

EMPETRUM, in botany, heath,* genas of the Dioecia Triandria class and order. Natural order of Erica?, Jussieu. Essential character: male, calyx three-parted; corolla three-pctalled; stamens long: female, calyx three-parted; corolla three-petailed ; stylos nine; berry nine-seeded. There are two species; ro. E. album, white-berried heath, and E. nigrum, black-berried heath, crow or crake berry. These are low shrubs, seldom propagated in gardens, unless for variety's sake. They are natives of wild mountains, where the soil is heathy and full of bo;rs.

EM PIS, in natural history, a genus of insects of the order Diptcra. Generic character: mouth with an inflected sucker and proboscis; sucker with a single-ralvrd sheath and three bristles; feelers short, filiform ; antenna; setaceous. These minute insects live likewise by sucking out the blood and juices of other animals. There are about 30 species. One of the most common species is the E. livida, which is a brownish fly; the wings are transparent, with dark veins. They are observed in fields and gardens. E. borealis, is of a more slender form than the common window fly, and of a blackish colour, with large, broad, oval wings, of a brown colour, and rufous legs, varied with black.

EMPLASTRUM, in pharmacy, a com-' position for external use, generally spread upon leather, linen, or some other convenient thing before it is applied. See PharMacy. The following is a recipe for making the Ladies' Court Plaster: " Dissolve five ounces of isinglass in a pint of water, and having ready a quantity of thin black sarsenet, stretched in a proper frame, apply the solution warm with a brush equally over the surface. This, is to be repeated, after it is dry, two or three times." Some give it a coat of gum benzoin dissolved in alcohol; but this is injurious rather than beneficial.

EMPLEURUM, in botany, a genus of the Monoecia Tetrandria class and order. Natural order of Aggregata\ Rutaet.T, Jussieu. Essential character: male, calyx fonr-cleft; corolla none: female, calyx Iburclcft, inferior; corolla none; stigma cylindric, placed on the lateral toothlet of the germ; capsule opening on the side; seed one, arilled. There is but one species; pis. E. sennlatum, Cape empleuniui. This is a shrub, with wand-like, even branches; leaves like those of a willow, alternate, subpetioled, linear-lanceolate, even above, beneath longitudinally wrinkled; peduncles few-flowered, lateral, much shorter than the leaves; flowers small, most of them male; capsules usually solitary, incurved, with a beak of the same length.

EMULSION, a milky looking fluid caused by an imperfect combination of oil with water by means of mucilage, gluten, &c. All oily farinaceous seeds, as nuts, almonds, linseed, &c. form an emulsion by trituration with water: yolk of egg, which is a natural compound of oil and albumen, makes a similar emulsion.

ENAMELLING. Ncri on Glass, with the notes of Merret and Kunckel, afford a variety of good receipts for making enamels, though much still remains to be done in this art. The art is indeed retarded by the considerable advantages the enameller derives from the discovery of any colour uncommonly brilliant, clear, or hard. On this account the artist naturally endeavours to Veep his process a secret, as the source of private gain. The principal ingredients of enamel colours are, however, well known.

There are two kinds of enamel; the opaque and the transparent. Transparent enamels are usually rendered opaque by adding putty, or the white oxide of tin, to them. The basis of all enamels is therefore a perfectly transparent and fusible glass. The oxide of tin renders this a beautiful white, the perfection of which is greater when a small quantity of manganese is likewise added. If the oxide of tin be not sufficient to destroy the transparency of the mixture, it produces a semi-opaque glass, resembling the opal.

Yellow enamel is formed by the addition of oxide of lead or antimony. Kunckel likewise affirms that a beautiful yellow may be obtained from silver.

Red enamel is formed by the oxide of gold, and also by that of iron. The former is the most beautiful, and stands the fire, which the. latter does not.

Oxide of copper affords a green, manganese a violet, cobalt a blue, and iron a very fine black. A mixture of these enamels produces a great variety of intermediate colours, according to their nature and proportion. In this branch of the art the coloured enamels are sometimes mixed with

each other, and sometimes the oxides are mixed before they are added to the vitrious bases.

The enameller who is provided with a set of good colours is very far from being in a situation to practise the art, unless he b« skilled in the methods of applying them, and the nature of the grounds upon which they are to be laid. Many of the metals arc too fusible to be enamelled, and most of them are corroded by the action of the fused glass. For this reason none of the metals are used but gold, silver, and copper. Platina has indeed been used; but of its effects and habitudes with enamel veiy little can be said, for want of a sufficient number of experiment.-*.

The purest gold, of 24 carats, is calculated to produce.the best effect with enamel. 1. Because it entirely preserves the metallic brilliancy, without undergoing any oxidation in the fire. 2. Being less fusible, it will admit of a more refractory, and consequently a harder and more beautiful enamel. It is not usual, however, to enamel on finer gold than It carats; and the operation would be very defective, if a coarser kind than that of 18 carats were used. For in this case more alkali must be added to the enamel to render it more fusible, and this addition would, at the same time, render it softer and less brilliant.

Rejecting all these exceptions, the following description may be taken, by way of example, of fixing a transparent blue enamel npon gqld of 22 carats.

The artist begins his operation by breaking his enamel into small pieces in a steel mortar, and afterwards pulverizing it in a mortar of agate. He is careful to add water in this part of the process, which prevents the splinters of glass from Hying about. There are no means of explaining the point at which the trituration ought to be given up, as this can be learned only by experience. Some enamels require to be very finely triturated; but others may be used in the form of a coarse powder. As soon as he apprehends that his enamel is sufficiently pounded, he washes it by agitation in very clear water, and pouring off the fluid as it becomes turbid. This process, which is made for carrying off dust and every other impurity from the enamel, is continued until the water comes off as clear as it was poured on.

The workman pnts his enamel thus prepared into a white earthen or china saucer, with water poured on it to the depth of ■bout one-tenth of an inch. He afterwards takes up the enamel with an iron spatula as equally as possible. As the enamel here spokeu off is transparent, it is usual to ornament the gold with rose work, or other kinds of work, calculated to produce a good affect through the enamel.

The thickness of this first layer depends entirely upon its colour: delicate colours in general require that it should have no great thickness.

The moist enamel being thus placed, is dried by applying a very clean half-worn linen cloth to it, which must be very carefully done to avoid removing the enamel by the action of wiping.

In this state the piece is ready for the fire. If it be enamelled on both sides, it is placed upon a tile, or iron plate, hollowed out in such a manner that the uncovered edges of the piece alone are in contact with the support. But if it be enamelled on one side only, it is simply laid upon the plate, or upon a tile. Two things, however, require to be attended to. 1. If the work be very small, or not capable of being enamelled on the opposite side, the iron plate must be perfectly fiat, in order that the work may not bend when softened by heat. 3. If the work be of considerable size, it is always counter-enamelled, if possible; that is to say, an enamel is applied on the hack surface, in order to counteract the effect which the other coating of glass might produce on the soft metal when it came to contract by cooling.

The enaiueller's furnace is square, and built of bricks bedded in an earth proper for the purpose. It may be considered as consisting of two parts, the lower part which receives a muffle resting on the floor of the furnace, and open on both sides.

The upper part of the furnace consists of a fire place, rather larger and longer than the dimensions of the muffle. The fire place contains the muffle, and must surround it on all sides, except at the bottom. The charcoal is put in at a door above the mnffle, which is closed as soon as the lire is lighted. A chimney proceeds from the summit of the furnace with a moderate aperture, which my be closed at the pleasure of the artist, by applying a cast iron plate to it. This furnace differs from that of the assayer, in the circumstance that it is supplied with air through the muffle itself: far if the draught were beneath the muffle, the heat would be loo strong, and could not be stopped when requisite.

As soon as the fire is lighted, and the muffle has acquired the requisite degree of ignition, the charcoal is disposed towards the lower part of the muffle in such a manner as that it shall not fall upon the work, which is then conveyed into the muffle with the greatest care upon the plate of iron or earthern-ware, which is taken out by long spring pincers. The work is* placed as near as possible at the farther extremity of the muffle; and as soon as the artist perceives a commencement of fusion, he turns it round with great delicacy, in order that the fusion may be very uniform. And as soon as he perceives that the fusion has entirely taken place, he instantly removes it out of the furnace : for the fusion of gold happens so very near to that of the enamel, that the neglect of a few seconds might be attended with considerable loss.

When the work is cooled, a second coat of enamel is applied in the same manner as the first, if necessary. This and the same cautious management of the fire are to be repeated for every additional coat of enamel the nature of the work may demand.

As soon as the number of coatings are sufficient, it hecoraes necessary to give an even surface to the enamel, which though polished by the fire, is nevertheless irregular. This is done with a fine grained Lancashire file, and water. As the file wears smooth, sand is used. Much precaution and address are required in this part of the work, not only because it is easy to make the enamel separate in splinters from the metal, but likewise because the colour would not be uniform if it were to be ground thinner at one part than at another.

The deep scratches of the file are in the next place taken cut by rubbing the surface with a piece of deal wood and fine sand and water. A polish is then given by a second ignition. This polish, however, is frequently insufficient, and not as perfectly uniform as the delicacy of the work may require.

The substance used by the cnameIlcrs as a polishing material is known by the name of rotten-stone, which is prepared bypounding, washing, decanting off' the turbid water, suffering the fine suspended particles to subside from this water, and lastlylevigating it upon a glass plate.

The work is then cemented to a square piece of wood, with a mixture of resin anil brickdust, and by this means fixed in a vice.

The first operation of polishing is made

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