smell, which common blends yield only when treated with marine or vitriolic acids. It contains 062 per cent. of auriferous silver. The reddish-brown is still poorer, and seems a mixture of blend, manganese, lead, and arsenic, with a small proportion of auriferous silver. The red exposed to the blow-pipe gives a purple tinge to borax if nitre be added. The black does the same, even without that addition, a sign that they contain manganese.

The manganesian ore consists of thin laminæ, of a gray color, somewhat withered, inserted in a matrix of whitish manganese. According to Hacquet it is very poor in gold, but baron Born tells us it contains twenty-five per cent. of this metal, and is the richest of all the ores found in that country. Yet it is so light, that it is called

cotton ore.

The sylvanitic ore; Weisses golderz of the Germans; Aurum Graphicum, of some; is according to baron Born of a whitish color, intermediate betwixt that of antimony and bismuth, Lustre, 3. It consists of amorphous plates, whose fracture is granular, like that of steel.

Its fragments prismatic. Its hardness from 4 to 5. Brittle. Its specific gravity, 5.723; its matrix an aggregate of lithomarga and quartz, with pyrites interspersed. Before the blow-pipe it decrepitates and melts like lead. It burns with a lively brownish flame and disagreeable smell, and at last vanishes in a white smoke, leaving only a whitish earth.

According to Wallerius, native gold is found, 1. In solid masses. In Hungary, Transylvania, and Peru. 2. In grains. In the Spanish West Indies. 3. In a vegetable form, like the branches or twigs of plants. 4. In a drusic figure, as if composed of groups or clusters of small particles united together, found in Hungary. 5. Čomposed of thin plates, on thin pellicles covering other bodies, found in Siberia. 6. In a crystalline form in Hungary. Gold is also found in the form of thick solid pieces. It is in general more frequently imbedded in quartz, and mixed with it than with any other stone; and the quartz in which the gold is found in the Hungarian mines, Mr. Magellan tells us, is of a peculiarly mild appearance. Sometimes, however, it is found in limestone, hornblende, &c. Europe is principally supplied with gold from Chili and Peru in South America. A small quantity is likewise imported from China and the coast of Africa. The principal gold mines of Europe are those of Hungary, Saltzburg, and Adelfors in Smaland. Some gold is also extracted from the silver mines of Östersilvarberget, in the province of Dalarne. Native gold has been found in Lapland, above Tornea, and in Westmanland. In Peru it is found mixed with a stony matter not well known, from which it is extracted by amalgamation. Sometimes kernels or lumps of a spongy texture, and very light, are met with, which contain a good quantity of gold dust. Gold is also found separate from any matrix, in lumps of visible grains mixed with sand in the beds of rivers.

Perfectly pure gold may be obtained, by dissolving the gold of commerce in nitro-muriatic acid, and precipitating the metal, by adding a

weak solution of sulphate of iron. The precipitate, after being well washed and dried, is pure gold. For the methods of analysing the ore or metal, see ASSAYING, CUPEL, METALLURGY, &c.

Pure gold is very soft, tough, ductile, and malleable, unaltered by the most powerful furnaces, but volatilised by the intense heat of powerful burning mirrors; and it has been driven up in fumes by a stream of oxygen urged upon it when red hot. The electric shock converts it into a purple oxide, as may be seen by transmitting that commotion through gold leaf, between two plates of glass; or by causing the explosive spark of three or more square feet of coated glass to fall upon a gilded surface. A heat of 32° W., or perhaps 1300° F. is required to melt it, which does not happen till after ignition. Its color, when melted, is of a bluish-green; and the same color is exhibited by light transmitted through gold leaf. But silver, copper, and all the rest of the metals which can be formed into leaves, are perfectly opaque.

No acid acts readily upon gold but aqua regia and aqueous chlorine. Chromic acid, added to muriatic, enables it to dissolve gold.

When gold is immersed in aqua regia, an effervescence takes place, and the solution tinges animal matters of a deep purple, and corrodes them. By careful evaporation, fine crystals of a topaz color may be obtained. The gold is precipitated from its solvent by a great number of substances. Lime and magnesia precipitate it in the form of a yellowish powder. Alkalies exhibit the same appearance; but an excess of alkali redissolves the precipitate. The precipitate of gold, obtained from aqua regia by the addition of a fixed alkali, appears to be a true oxide, and is soluble in the sulphuric, nitric, and muriatic acids; from which, however, it separates by standing, or by evaporation of the acids. Gallic acid precipitates gold of a reddish color, very soluble in the nitric acid, to which it communicates a fine blue color.

Ammonia precipitates the solution of gold much more readily than fixed alkalies. This precipitate, which is of a brown, yellow, or orange color, possesses the property of detonating with a

considerable noise when gently heated. It is known by the name of fulminating gold. See PoWDER, FULMINATING. When precipitated from this solution by tin, it forms the purple precipitate of Cassius, so much used in enamelling. This consists of an oxide of gold, mixed with an oxide of tin. Sulphurets precipitate gold from its solvent, the alkali uniting with the acid, and the gold falling down combined with the sulphur; of which, however, it may be deprived by moderate heat.

The solution of gold in sulphuric ether appears to crystallise after a considerable time. Mr. Sivright having allowed a solution of gold in sulphuric ether to stand four days in a vessel, with a cork and a piece of leather tied over it, found that a great part of the liquid had evaporated, leaving the gold in the form of a thin plate, which has the usual brightness of pure gold, and resembles the flat pieces of native copper found in Cornwall. There were distinct crystals in one or two parts of the plate.

The peroxide of gold thrown down by potash, from a solution of the neutral muriate, consists, according to Berzelius, of 100 gold and twelve oxygen. It is probably a trit-oxide. The protoxide of a greenish color is procured by treating with potash water muriate of gold, after heat has expelled the chlorine. It seems to consist of 100 metal +4 oxygen. The prime equivalent of

gold comes out apparently 25.

Most metals unite with gold by fusion. With silver it forms a compound, which is paler in proportion to the quantity of silver added. It is remarkable, that a certain proportion, for example a fifth part, renders it greenish, but occasions hardly any perceptible alteration of ductility, hardness, or mean specific gravity.

A strong heat is necessary to combine platina with gold it greatly alters the color of the gold, if its weight exceed the forty-seventh part of the

mass.

Mercury is strongly disposed to unite with gold, in all proportions, with which it forms an amalgam: this, like other amalgams, is softer the larger the proportion of mercury. It softens and liquifies by heat, and crystallises by cooling. Lead unites with gold, and considerably impairs its ductility, one-fourth of a grain to an ounce rendering it completely brittle. It gives an alloy externally resembling fine pale gold, but which is as brittle as glass, is wholly destitute of metallic lustre, and has a fine-grained porcellaneous appearance its specific gravity a little less than the mean. The very fumes of this metal are nearly as prejudicial to the ductility of gold as those of bismuth.

Copper renders gold less ductile, harder, more fusible, and of a deeper color. This is the usual addition in coin, and other articles used in society. Tin renders it brittle in proportion to its quantity; but it is a common error of chemical writers to say, that the slightest addition is sufficient for this purpose. When alloyed with tin, however, it will not bear a red heat. With iron it forms a gray mixture, which obeys the magnet. This metal is very hard, and is said to be much superior to steel for the fabrication of cutting instruments.

With bismuth, in the proportion of thirtyeight grains to the ounce, it yields an alloy of a pale greenish yellow, excessively brittle, and exhibiting a fine-grained earthy fracture: its specific gravity somewhat greater than the mean. If standard gold be alloyed with even a quarter of a grain of bismuth in the ounce, the mixture, although in color and texture resembling gold, is yet perfectly brittle.

Arsenic, on account of its volatility, can be combined with gold only in small proportions. The alloy, or mixed metal hence produced, is of a gray color, coarse granular fracture, and very

brittle.

Antimony, mixed by fusion with either fine or standard gold in the proportion of not more than gr. to the ounce (being not more than of the whole mass), will give a brittle compound of a close granular fracture, with little metallic lustre: while, with a change quite as extraordinary as in nickel, mixed in the proportion of thirty-eight grains to the ounce, produces an alloy of the

color of fine brass, with a coarse-grained earthy fracture, and very brittle: its specific gravity being somewhat less than the mean. With manganese, in its black oxide, gold will combine, and produce an alloy of a reddish gray, capable of receiving a brilliant lustre like steel: the mixed metal is exceedingly hard, and so far possessed of ductility as to be in some measure flattened by the hammer before it breaks.

Zinc greatly injures the ductility of gold, and, when equal in weight, a metal of a fine grain is produced, which is said to be well adapted to form the mirrors of reflecting telescopes, on account of the fine polish it is susceptible of, and its not being subject to tarnish. The alloys of gold with molybdena are not known. It could not be mixed with tungsten, on account of the infusibility of this last substance.

Mr. Hatchett gives the following order of different metals, arranged as they diminish the ductility of gold: bismuth, lead, antimony, arsenic, zinc, cobalt, manganese, nickel, tin, iron, platina, copper, silver. The first three were nearly equal in effect; and the platina was not quite pure.

For the purposes of coin, Mr. Hatchett considers an alloy of equal parts of silver and copper as to be preferred, and copper alone as preferable to silver alone.

At

The limits of the ductility and malleability of gold are not known. According to Cronstedt, one grain of it may be stretched out so as to cover ninety-eight Swedish ells, equal to 63-66 English yards of silver wire; but Wallerius asserts, that a grain of gold may be stretched in such a manner as to cover 500 ells of wire. any rate, the extension is prodigious; for, according to the least of these calculations, the 1,000,000th part of a grain of gold may be made visible to the naked eye. Nor is its malleability inferior to its ductility. Poyle, quoted by Apligny in his Treatise of Colors, says, that one grain and a half of gold may be beaten into fifty leaves of one inch square, which, if intersected by parallel lines drawn at right angles to each other, and distant only the 100th part of an inch from each other, will produce 25,000,000 of little squares, each very easily discernible to the naked eye.

1

By the weight and measure of the best wrought gold leaf, it is found that one grain is made to cover 56 square inches; and from the specific gravity of the metal together with this ad measurement, it follows that the leaf itself is 152000 part of an inch thick. This, however, is not the limit of the malleability of gold; for the goldbeaters find it necessary to add three grains of copper in the ounce to harden the gold, which otherwise would pass round the irregularities of the newest skins, and not over them; and in using the old skins, which are not so perfect and smooth, they proceed so far as to add twelve grains. From further calculation it appears that sixteen ounces of gold, which would form a cube of about one inch and a quarter, would be sufficient to gild a silver wire equal in length to the circumference of the globe. See CHEMISTRY.

GOLDBEATER'S SKIN, n. s. The intestinum rectum of an ox, which goldbeaters lay between the leaves of their metal while they beat it, where

by the membrane is reduced thin, and made fit to apply to cuts or small fresh wounds, as is now the common practice.

When your gillyflowers blow, if they break the pod, open it with a penknife at each division, as low as the flower has burst it, and bind it about with a narrow slip of goldbeater's skin, which moisten with your tongue, and it will stick together. Mortimer.

GOLDEN FLEECE, in the ancient mythology, was the skin and fleece of the ram upon which Phryxus and Helle are said to have swum over the sea to Colchis; and which, being sacrificed to Jupiter, was hung upon a tree in the grove of Mars, guarded by two brazen-hoofed bulls, and a monstrous dragon that never slept; but was taken and carried off by Jason and the Argonauts. Some authors have endeavored to show that this fable is an allegorical representation of some real history, particularly of the philosopher's stone. Others have explained it by the profit of the wool-trade to Colchis, or the gold which they commonly gathered there with fleeces in the rivers. See ARGONAUTS.

GOLDEN FLEECE, Order of the, a military order instituted by Philip the Good, duke of Burgundy, 1427; thus named from a representation of the golden fleece, borne by the knights on their collars, which consisted of flints and steels. The king of Spain, as duke of Burgundy is grand master of the order; the number of knights is fixed to thirty-one. It is said to have been instituted on occasion of an immense profit which that prince made by wool; though others will have a chemical mystery couched under it, as that famous one of the ancients, which the adepts pretend to be the secret of the elixir vitæ, written on the skin of a sheep.

GOLD THREAD, or spun gold, is a gilt wire, wrapped or flatted over a thread of yellow silk, by twisting it with a wheel and iron bobbins. By means of a curious machinery, a number of threads is thus twisted at once by the turning of a wheel. The principal art consists in so regulating the motion, that the several circumvolutions of the wire, on each thread, may just touch one another, and form, as it were, one continued covering. At Milan, it is said, they make a sort of flatted wire, gilt only on one side, which is wound upon the thread, so that only the gilt side appears. There is also a gilt copper wire, made in the same manner as the gilt silver, chiefly at Nuremberg. The Chinese, instead of flatted gilt wire, use slips of gilt paper, which they interweave in their stuffs, and twist upon silk threads. GOLDONI, a celebrated dramatic author, born at Venice in 1707. Having shown an early attachment to dramatic performances his father, Dr. Goldoni, had a small theatre erected in his own house, in which, while a mere child, he and his companions amused themselves by acting comedies. Having finished his grammatical and rhetorical studies at Venice and Prague, he went to Rimini to study philosophy; but, preferring the theatre to Aristotle, he went off with a company of comedians to Chiozzo. After at tempting to study the law at Venice, he became secretary to the resident of that state at Milan. In this city he wrote his Venetian Gondolier, the first of his comedies that was acted and printed; and soon after composed several other

pieces for a Venetian company then at Milan, and whom he accompanied to Genoa, where he married. After visiting Tuscany, Florence, and Pisa, he returned to Venice, and wrote comedies for the theatre of St. Angelo. These cost him so little trouble, that it is said he wrote sixteen new comedies, besides forty-two other pieces for that theatre, within a year; and many of these, though so rapidly executed, are considered as his best productions. The first edition of his works was published in 10 vols. 8vo, 1753. He wrote afterwards a great number of pieces for the theatre at St. Luke, which were published under the title of The New Comic Theatre. He composed fifty-nine other pieces between 1753 and 1761; and, on the invitation of duke Philip, visited Parma, from whence he went to Rome. He next went to Paris on the invitation of M. Zenuzzi, the chief actor on the Italian theatre there, with whom he engaged for two years. After this, he was employed as an Italian teacher to the princesses, aunts to the unfortunate Louis XVI.; for which he received 4000 livres a-year, and a present of 100 louis d'ors in a gold box. In his sixty-second year he wrote a French comedy, entitled Bourru Bienfaisant, which was acted at Louis XVI.'s marriage; and for which he received 150 louis from the king, besides considerable sums from the performers and booksellers. He died at Paris in 1792, aged eightyfive. As a dramatic author, he is reckoned equal to the best comic poets of modern tiines; and in fertility of invention superior to them all. His whole works were printed at Leghorn, in 1788-91, in 31 yols. 8vo. He has been styled the Moliere of Italy; and Voltaire, in a letter to the marquis Albergati, called him the Painter of Nature. His favorite work, generally reckoned his master-piece, was his Terence. His last piece was his Volponi.

A GOLDSMITH, or Silversmith, is an artist who makes vessels, utensils, and ornaments, in gold and silver. There is a vast variety in the works made, and tools used, by goldsmiths, which we cannot here particularise. Works that have raised figures are cast in a mould, and afterwards carved, or polished and finished; plates or vessels of silver or gold are beat out from thin flat plates; table and tea-spoons, &c., are beat out from solid ingots, and their mouths struck up with a punch; tankards, and other vessels of that kind, are formed of plates soldered together, and their mouldings are beat, not cast. The business of the goldsmiths formerly required more labor than it does at present; for they were obliged to hammer the metal from the ingot to the thinness they wanted; but, since the invention of flatting-mills, the metals are reduced to the thinness required at a small expense. As the goldsmith often has to make his own moulds, he ought to be a good designer, and have a taste in sculpture: he also ought to know enough of metallurgy to be able to assay and refine gold and silver, and to mix the exact quantity of alloy. The goldsmiths in London employ different hands under them for the various branches of their trade; such as jewellers, box-makers, toy-makers, turners, gilders, burnishers, chasers, refiners, founders, &c. Their wares must be assayed by the wardens of

their own company in London, and marked; and the gold and silver must be of the standard fineness, under a penalty of £10. Any false metal may be seized and forfeited to the king. The cities of Edinburgh, York, Exeter, Bristol, &c., have also places appointed for assaying gold and silver plate. Plate sent to the assay-office, when discovered to be coarser than the standard, is broken and defaced; and the fees for assaying are limited.

GOLDSMITH (Oliver), was born at Roscommon, in Ireland, in 1729. His father, who possessed a small estate in that county, had nine sons, of whom Oliver was the third. After being instructed in the classics, he was, with his brother the Rev. Henry Goldsmith, placed in Trinity College, Dublin, about the end of 1749. In this seminary he took the degree of B. D.; but, his brother not being able to obtain preferment, Oliver turned to the study of physic; and, after attending some courses of anatomy in Dublin, proceeded to Edinburgh in 1751, where he studied medicine under the professors of that university. His benevolent disposition soon involved him in difficulties; and he was obliged precipitately to leave Scotland, in consequence of an engagement to pay a considerable sum for a fellow-student. A few days after, about the beginning of 1754, he arrived in Sunderland, near Newcastle, where he was arrested at the suit of a tailor in Edinburgh, to whom he had given security for his friend. By the good offices of Lachlan Maclane, esq. and Dr. Sleigh, then in college, he was delivered out of the hands of the bailiff; and took his passage on board a Dutch ship to Rotterdam, where, after a short stay, he proceeded to Brussels. He then visited great part of Flanders; and after passing some time at Strasburg and Louvain, where he took the degree of M. B., he accompanied an English gentleman to Berne and Geneva. He travelled on foot during the greatest part of his tour, having left England with very little money. Being capable of sustaining fatigue, and not easily terrified at danger, he became enthusiastically fond of visiting different countries. He had some knowledge of French and of music, and played tolerably well on the German flute; whicn, from an amusement, became at times the means of subsistence. His learning procured him an hospitable reception at most of the religious houses; and his music made him welcome to the peasants of Flanders and other parts of Ger'Whenever I approached,' he used to say, a peasant's house towards night-fall, I played one of my most merry tunes; and that procured me not only a lodging, but subsistence for the next day: but in truth, I must own, whenever I attempted to entertain persons of a higher rank, they always thought my performance odious, and never made me any return for my endeavours to please them.' On his arrival at Geneva, he was recommended as a travelling tutor to a young man who had been left a considerable sum of money by his uncle, a pawnbroker, near Holborn. During Goldsmith's continuance in Switzerland, he assiduously cultivated his poetical talents, of which he gave some proofs while at the college of Edinburgh.

many.

It was here he sent the first sketch of his delightful poem called The Traveller, to his brother the clergyman in Ireland, who lived with an amiable wife on an income of only £40 a-year. From Geneva Mr. Goldsmith and his pupil visited the south of France; where the young man, upon some disagreement with his preceptor, paid him the small part of his salary which was due, and embarked at Marseilles for Eugland. Our wanderer was left once more upon the world at large, and passed through various difficulties in traversing the greatest part of France. At length, his curiosity being satisfied, he bent his course towards England, and arrived at Dover the beginning of the winter of 1758. When he came to London, his cash did not amount to two livres. Being an entire stranger, his mind was filled with the most gloomy reflections. With difficulty he discovered that part of the town in which his old acquaintance Dr. Sleigh resided. This gentleman received him with the warmest affection, and liberally invited him to share his purse till some establishment could be procured for him. Goldsmith, unwilling to be a burden to his friend, eagerly embraced an offer which was made him soon after to assist the late Rev. Dr. Milner in an academy at Peckham; and acquitted himself greatly to the doctor's satisfaction; but having obtained some reputation, by the criticisms he had written in the Monthly Review, Mr. Griffith, the proprietor, engaged him in the compilation of it; and, resolving to pursue the profession of an author, he returned to London, as the mart where abilities of every kind meet distinction and reward. As his finances were not in a good state, he adopted a plan of the strictest economy; and took lodgings in an obscure court in the Old Bailey, where he wrote several ingenious pieces. The late Mr. Newberry, who gave great encouragement to men of literary abilities, became a patron to him, and introduced him as one of the writers in the Public Ledger, in which his Citizen of the World originally appeared, under the title of Chinese Letters. His fortune now began to improve. The simplicity of his character, the integrity of his heart, and the merit of his productions, made his company very acceptable to a number of respectable families; and he emerged from his shabby apartments in the Old Bailey to the politer air of the Temple, where he took handsome chambers, and lived in a genteel style. The publication of his Traveller, and his Vicar of Wakefield, was followed by the performance of his comedy of the Good-natured Man at CoventGarden theatre, and placed him in the first rank of the poets of the eighteenth century. Among many other persons of distinction who were desirous to know him, was the duke of Northumberland: and a circumstance that attended his introduction to that nobleman shows a striking trait of his character. I was invited,' said the Doctor., by my friend Mr. Percy, to wait upon the duke, in consequence of the satisfaction he had received from the perusal of some of my productions. I dressed myself in the best manner I could; and, after studying some compliments I thought necessary on such an occasion, proceeded to Northumberland-house, and ac