kept separate from the rest. After the whole of the litharge is removed, and the surface of the metal in the furnace becomes bright, a quantity of water is poured on it, to keep it from spirting, which it is apt to do when congealing. The metal thus obtained is subjected to a similar operation for about five hours, in a smaller furnace, and at a higher temperature, by which it is completely freed from the lead. With respect to the other method of reduction or separation—-amalgamation-the following is an outline of the more important steps, of which it consists. The ores best adapted to this process are native silver and vitreous silver. The first operation that requires description is the selection of the ores to form a proper mixture, with reference to the quantity of silver and sulphur they contain. It has been observed that the amalgamation process succeeds best when the silver produce is about seventy-five ounces to the ton of ore; at the same time, regard being had to the quantity of sulphur present, which is ascertained from the quantity of sulphuret in the ore, previously learned by an assay in the crucible. The sulphur is got rid of, by adding to the mixture of raw ore ten per cent. of common salt, by which, during the furnace operation, the sulphur becomes acidified, and the acid thus formed, uniting with the base of the salt, forms sulphate of soda; whilst the muriatic acid, thus set free, combines with the silver in the ore, that was not in the metallic state, and forms muriate of silver. In this state, the ore is subjected to various mechanical operations, with riddles, mills and sieves, until it is reduced to an impalpable powder. It is then submitted to the action of mercury. This operation is performed in barrels, which are arranged so as to revolve on their axes. The mixture or charge in each barrel consists of sifted calcined ore, mercury, metallic iron, and water, in certain proportions. The ore is composed of sulphate of soda, muriate of silver, and other metals and earthy matters. By the process of amalgamation, the barrels being made to revolve during a period of sixteen or eighteen hours, the muriate of silver becomes decomposed by the action of the iron on its acid; and the silver, thus reduced to the metallic state, combines with the mercury, forming what is termed amalgam, whilst the sulphate of soda, the muriate of iron, and other salts, become dissolved in the water. The silver combined with mercury is then filtered, by which the

surplus metal is separated, and a compound remains in the sack, consisting of six parts of mercury and one of silver. This amalgam is subjected to the action of heat in a distilling furnace, by which the mercury is sublimated, and the silver remains. Šilver is also sometimes separated from copper by the process of eliquation. The eliquation is effected by means of lead, which, possessing a greater affinity for silver than for copper, combines with the former, when brought into fusion with the alloy, and forms a new metallic compound. The argentiferous lead, thus obtained, is subjected to the usual processes of cupellation, and the coarse copper, from which the silver has been separated, is refined.-We shall now take notice of the mines of silver in different parts of the world, which furnish the silver of commerce. Those of Mexico and South America are incomparably more important than those of all the rest of the world. Mexico alone has above three thousand mines, or excavations for silver ores, which produced annually, during the last ten years of the seventeenth century, about $4,000,000. The mines of Guanaxuato yielded nearly one quarter of this amount; while the single mine of Valenciana, situated in the same district, has afforded, for years together, during the last thirty years, between one and two million dollars. Nor are the ores of Mexico, for the most part, rich in silver; but the rich produce of that country has depended upon their abundance, and the facility with which they have been explored. In Peru, the annual produce of this metal was formerly as great as $2,000,000; the major part of which was furnished by the mines of Tasco, of Chota, and of Huantajaya. Chile affords $150,000 per annum. contains the celebrated mines of Potosi, discovered in 1545, and which have produced, according to the estimate of Humboldt, from the time of their discovery, the enormous amount of $1,150,000,000. These mines have diminished in value of late, though they still rank next to those of Guanaxuato. The celebrated mines of Kongsberg, in Norway, once so rich in native silver, have now become in a great measure exhausted. They are estimated to have produced above $20,000,000 since they were opened in 1623. The most important silver mines of Europe at present, are those of Saxony, Hungary, and the Hartz. The annual produce of Saxony is about $250,000; while those of the Hartz and of Hungary are each about the

Buenos Ayres

same. Within the last sixteen years there has been a great increase in the produce of silver from the Russian mines. According to a communication from baron Humboldt, made since his return from Asia, to the editor of Poffendorf's Annalen, it appears that the annual produce of the mines of precious metals of Europe and Asiatic Russia amounts to 25,500 marcs of gold, and 292,000 marcs of silver;. of which 76,500 of silver and 22,000 of gold are supplied from the Russian empire. The value of all this silver is about $2,353,000. The present annual produce of all the silver mines in the world is probably within $20,000,000.

SILVER FISH. (See Gold Fish.) SILVER TREE (leucadendron argenteum); so called from the appearance of the leaves, which are lanceolate and silky. It is a large evergreen shrub, with handsome foliage, a native of the cape of Good Hope, together with the other species of the genus, and is a favorite in greenhouses. It belongs to the proteacea, the most remarkable family of plants in the southern hemisphere, and one which contributes largely to give peculiar features to the vegetation of that portion of the globe. More than four hundred species of these plants are known, which are arranged in numerous genera. They are usually shrubs or small trees, but some attain large dimensions: the leaves are simple, entire or serrated, in most species flat, but sometimes cylindrical or threadshaped; the flowers are sometimes distinct, upon solitary foot-stalks, or in clusters, spikes, or corymbs, with bractea at the base; sometimes they are sessile, situated upon a common receptacle, surrounded with a many-leaved involucre, or are disposed in scaly cones; the color is green, yellow, or red: in short, the remarkable differences in the habit, foliage and flowers of these plants have given rise to the name of the order. The great er proportion of these plants inhabit New Holland, where they adorn large tracts of country; they are numerous, likewise, at the cape of Good Hope, but a few species only are found in the southern parts of South America. They are generally favorite green-house plants, and are not delicate with respect to cold; but their culture, in other respects, requires many precautions.

SILVERING. The application of silver leaf is made in the same way as that of gold, for which see Gilding. Copper may be silvered over, by rubbing it with the following powder:-Two drachms of

tartar, the same quantity of common salt, and half a drachm of alum, are mixed with fifteen or twenty grains of silver, precipitated from nitric acid by copper. The surface of the copper becomes white when rubbed with this powder, which may afterwards be brushed off and polished with leather. A cheap silvering is prepared as follows:-Half an ounce of silver that has been precipitated from aquafortis by the addition of copper, common salt, and muriate of ammonia, of each two ounces, and one drachm of corrosive muriate of mercury, are triturated together, and made into a paste with water; with this, copper utensils of every kind, that have been previously boiled with tartar and alum, are rubbed, after which they are made red-hot, and then polished. The intention of this process appears to be little more than to apply the silver in a state of minute division to the clean surface of the copper, and afterwards to fix it there by fusion; and, accordingly, this silvering may be effected by using the argentine precipitate, here mentioned, with borax or mercury, and causing it to adhere by fusion. The dialplates of clocks, the scales of barometers, and other similar articles, are silvered by rubbing upon them a mixture of muriate of silver, sea salt, and tartar, and afterwards carefully washing off the saline matter with water. In this operation, the silver is precipitated from the muriatic acid, which unites with part of the coppery surface. It is not durable, but may be improved by heating the article, and repeating the operation till the covering seems sufficiently thick. The silvering of pins is effected by boiling them with tin filings and tartar. Holton mirrors or globes are silvered by an amalgam, consisting of one part by weight of bismuth, half a part of lead, the same quantity of pure tin, and two parts of mercury. The solid metals are to be first mixed together by fusion, and the mercury added when the mixture is almost cold. A very gentle heat is sufficient to fuse this amalgam. In this state it is poured into a clean glass globe, intended to be silvered, by means of a paper funnel, which reaches to the bottom. At a certain temperature it will stick to the glass, which by a proper motion may thus be silvered completely, and the superfluous amalgam poured out. The appearance of these toys is varied by using glass of different colors, such as yellow, blue, or green. To silver looking-glasses, the following articles are necessary:-first, a square marble table, or smooth stone,

well polished, and ground extremely true, with a frame round it, or a groove cut in its edges, to keep the superfluous mercury from running off; secondly, lead weights covered with cloth, to keep them from scratching the glass, from one pound weight to twelve pounds each, according to the size of the glass laid down; thirdly, rolls of tin-foil; fourthly, mercury. The artist then proceeds as follows:-the tin-foil is cut a little larger than the glass, and laid flat upon the stone, and with a straight piece of hard wood, about three inches long, stroked every way, that there may be no creases or wrinkles in it: a litthe mercury is then dropped upon it, and with a piece of cotton wool, or hare's foot, it is spread all over the foil; then, the marble slab being kept nearly level with the horizon, the mercury is poured all over the foil, which is covered with a fine paper; two weights are placed near its lower end, to keep the glass steady, while the artist draws the paper from between the silver-foil and the glass. This must be done with great care, so that no air-bubbles be left. After the paper is drawn out, weights are placed upon the glass to press out the superfluous mercury, and make the foil adhere. Another method is, to slide the glass over the foil without the assistance of paper. To make shell silver, silver leaf is ground with gum-water, or honey: the gum, or honey, is washed away, and the powder which remains is used with gum-water, or white of eggs, laid on with a hair pencil.

SILVESTRE DE SACY. (See Sacy.) SIMEON STYLITES. (See Stylites.) SIMOIS; a river of Troas, which rises in mount Ida, and falls into the Xanthus. It is celebrated by Homer, and most of the ancient poets, as many battles were fought in its neighborhood during the Trojan war. Modern travellers call it a sinal rivulet, and some have even disputed its existence. (See Scamander.)

SIMON MAGUS, or the Magician; an impostor, mentioned in the Acts of the Apostles, a native of Samaria, who pretended to be an con of an exalted nature, and called himself the supreme power of God. (See Gnostics.) Struck with astonishment at the miracles of the Apostles, he offered them money for their secret. (See Simony.) He then went about making proselytes, carrying with him a Tyrian courtesan, whom he represented as Helen, who had been the cause of the Trojan war, and sometimes as Minerva; calling her, at the same time, the first intelligence, or mother of all things. Other

stories are related of him, but are not well authenticated. It has also been said that he was worshipped as a god at Rome, and that his statue was erected there, with the inscription Simoni Deo sancto. His followers are called Simonians. (See Heretics.)

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SIMON, ST.; an ancient French family, which claims to derive its origin, through the counts of Vermandois, from Charlemagne. Louis de Rouvroy, duke de St. Simon, a peer of France, known as the author of some very curious memoirs, was born in 1675, and died in 1755. He was. employed in several diplomatic missions, and was made one of the council of regency by the notorious regent, duke of Orleans (q. v.), after whose death he retired to his estates. His memoirs remained a long time in manuscript, and were afterwards published in a mutilated form, with many suppressions. The first complete edition appeared in Paris, in 1829-30 (in 21 vols., Svo.), under the title of Mémoires complets et authentiques du Duc de Saint Simon sur le Siècle de Louis XIV, et la Régence, publiés pour première Fois sur le Manuscrit original entièrement écrit de la Main de l'Auteur, par M. le Marquis de Saint Simon.-Claude Henri, count de St. Simon, founder of the politicophilosophical-religious sect of St. Simonians, or of the New Christianity, which has recently attracted attention in France, was born in 1760. We know little of his youth; but he appears to have been early tinctured with a spirit of enthusiasm, as we are told that he caused himself to be called, every morning, with the words, "Get up, count; you have great things to accomplish." He was attached to the French auxiliary corps, which served in this country in the last years of our revolutionary war, and, soon after his return to France, was promoted to a colonelcy. Previous to the breaking out of the French revolution, the count travelled in Holland and Spain; but he took no part in the great events of 1789. He died in 1825, the last thirty-four years of his life, if we may believe his own account, having been devoted to the objects of his mission, as the apostle of the New Christianity. His disciples are not very communicative in regard to the history of their founder, whose reputation appears not to have been always the best. In 1790, he entered into financial speculations, for the purpose, as we are told, of raising the funds necessary to aid his great projects. His partner not participating in his philanthropic views, St. Simon re