present diminution of the quantity of silver from what it was formerly, is stated by Pazos as four to one; by Humboldt the diminution is stated to be greater; but they are still the richest mines in South America. The number of mines worked was formerly 300; in 1803, only 97. According to Helms, nothing can equal the ignorance with which the mining operations are conducted; if judiciously managed, the quantity of silver might be doubled.

POT-POURRI (French) signifies the same as olla podrida. (q. v.) It also signifies a vessel containing flowers or plants, and more generally any sort of medley. (See Quodlibet.)

POTSDAM; a residence of the king of Prussia, seventeen miles west from Berlin, on the river Havel, with 25,000 inhabitants, of whom 5700 are soldiers. Several troops of the guards are always stationed here. It has five churches, one synagogue, and 1600 houses. It contains palaces and gardens, chiefly built and laid out by Frederic the Great (whose favorite residence was Potsdam), at an immense expense, a military orphan house for 600 children, in exemplary order (besides 2000 other children of military persons who are provided for by this establishment), with various other public buildings; but the general appearance of the place is cheerless, because it has no manufacturing industry, nor commerce. A very fine road leads from Berlin to Potsdam, through a most uninteresting plain. Potsdam itself, however, is rather pleasantly situated; lon. E. 13° 5; lat. N. 52° 24′ 19′′.

POTTER, DE. (See Netherlands, in the Appendix at the end of the work.)

POTTER, John, primate of all England, born in 1674, was the son of a linen draper of Wakefield, in Yorkshire, in the grammar school of which town he received the rudiments of a classical education. He then became a member of University college, Oxford, where, in his twentieth year, he published Variantes Lectiones et Notæ ad Plutarchi Librum de audiendis Poetis; et ad Basilii magni Orationem ad Juvenes quomodo cum Fructu legere possint Græcorum Libros. The next year he became fellow of Lincoln college, and, in 1697, printed an edition of Lycophron. Soon after appeared his Archeologia Græca, or the Antiquities of Greece, in 2 vols., 8vo., which has gone through many editions, and is almost indispensable to the classical student. In 1706, he became chaplain to queen Anne, on which occasion he graduated as doctor in divinity. In 1715,

being then regius professor of divinity, he was raised to the see of Oxford, and, in 1737, was appointed archbishop of Canterbury. He died in 1747. His works, besides those enumerated, are, a Discourse on Church Government (1707); an edition of Clemens Alexandrinus (1714); and theological works, printed together, in 3 vols., 8vo. (Oxford, 1753).

POTTER, Robert, born in 1721, graduated at Cambridge, 1741, died in 1804, was an admirable classical scholar, distinguished by his excellent translations of the works of Eschylus (1777), Euripides, Sophocles (1788), equally remarkable for the spirit and fidelity with which they are rendered.

POTTER, Paul; a painter of animals, born at Enkhuisen, in 1625, was the son of Peter Potter, a painter, from whom he received his first instruction, but to whom he himself was greatly superior. As early as his fifteenth year he had executed a work which was universally admired; and, after he settled at the Hague, he was unable to satisfy the demand for his works. His department was the painting of animals and landscapes, but he was more particularly successful in the former; the latter were designed merely to afford an opportunity for exhibiting animals in different attitudes and circumstances. His coloring is uncommonly brilliant, and the separate parts are most delicately executed, yet without any appearance of stiffness or mannerism. His pieces were generally of a small size; but there is one in the Louvre, which originally belonged to the prince of Orange, representing a man and cattle as large as life. His walks were always occupied in study; whatever struck his fancy, he immediately sketched. He died in 1654, at the age of twenty-nine years, at Amsterdam, where he had been residing two years. His engravings are not less esteemed than his paintings. His cabinet pieces command a very high price. His celebrated Cow, which was taken from the Cassel gallery to Paris, was bought by Alexander, emperor of Russia, for about 4000 dollars.

POTTER'S CLAY. (See Clay.)

POTTERY. The art of forming vessels or utensils of any sort of clay, kneaded with water, and hardened in the fire, is of high antiquity; and we find mention of earthen ware in the Mosaic writings. The Greeks, at an early period, had potteries at Samos, Athens, and Corinth. Demaratus, father of Tarquinius Priscus, is said to have instructed the Etruscans and Romans in this art, of which the Etruscan vases show the great perfection.

In the different kinds of earthen ware, the different degrees of beauty and costliness depend upon the quality of the raw material used, and upon the labor and skill expended in the operation. (See Clay.) The cheapest products of the art are those made of common clay, similar to that of which bricks are formed, and which, from the iron it contains, usually turns red in burning. (See Bricks.) Next to this is the common crockery ware, formed of the purer and whiter clays, in which iron exists only in minute quantities. Porcelain, which is the most beautiful and expensive of all, is formed only from argillaceous minerals of extreme delicacy, united with siliceous earths, capable of communicating to them a semi-transparency, by means of its vitrification. (See Fayence, and Porcelain.) Though the various kinds of pottery and porcelain differ from each other in the details of their manufacture, yet there are certain general principles and processes, which are common to them all. The first belongs to the preparation of the clay, and consists in dividing and washing it, till it acquires the requisite fineness. The quality of the clay requires the intermixture of a certain proportion of siliceous earth, the effect of which is to increase its firmness, and render it less liable to shrink and crack, on exposure to heat. In common clay, a sufficient quantity of sand exists in a state of natural mixture, to answer this purpose. But in the finer kinds, an artificial admixture of silica is necessary. The paste which is thus formed is thoroughly beaten and kneaded to render it ductile, and to drive out the air. It is then ready to receive its form. The form of the vessel intended to be made is given to the clay either by turning it on a wheel, or by casting it in a mould. When dry, it is transferred to the oven or furnace, and there burnt till it acquires a sufficient degree of hardness for use. Since, however, the clay is still porous, and of course penetrable to water, it is necessary to glaze it. This is done by covering the surface with some vitrifiable substance, and exposing it a second time to heat, until this substance is converted into a coating of glass. (See Glazing.) In the coarse earthen ware, which is made of common clay, the clay, after being mixed and kneaded, until it has acquired the proper ductility, is transferred to a revolving table, called the wheel. A piece of clay being placed in the centre of this table, a rotary motion is communicated to it by the feet; the potter then begins to shape it with his

hands; the rotary motion gives it a circular form, and it is gradually wrought up to the intended shape, a tool being occasionally used to assist the finishing. The vessels are now set aside to dry, after which they are baked in the oven or kiln. Stone ware may be formed of the clays which are used for other vessels, by applying to them a greater degree of heat, which increases their strength and solidity. These vessels afford the material of their own glazing by the vitrification of their surface. When the furnace in which they are burnt has arrived at its greatest heat, a quantity of muriate of soda, or common salt, is thrown into the body of the kiln. The salt rises in vapor and envelopes the hot ware, and by the combination of its alkali with the siliceous particles on the surface of the ware, a perfect vitrification is produced. This glazing, consisting of an earthy glass, is insoluble in most chemical agents, and is free from the objections to which vessels glazed with lead are liable-that of communicating an unwholesome quality to liquids contained in them, by the solution of the lead in common acids which they frequently contain. White ware is made of white clay, or of clay containing so little oxide of iron that it does not turn red in burning, but improves its whiteness in the furnace. (See Wedgewood.) The manufacture of pipes is also a branch of pottery. Pano, a Spanish monk, first introduced earthen pipes from St. Domingo into Spain. A manufactory was established in England by James I, in 1621, and not long after, a similar one was set up at Tergow by the Dutch. The clay, used for pipes must burn white, be carefully cleansed, and kneaded up to a tenacious paste. Small lumps of the paste, of a suitable size, are then formed on the wheel into cylinders, bored by the laborer with a wire, and shaped in brass moulds. The head is then hollowed by a stopper pressed into it, and the whole is again smoothed and polished, and the pipes are then baked. After baking, they are again polished with wax, gum tragacanth, or grease. (For enameled ware, see Enameling.) See the History of the Manufacture of Porcelain and Glass, No. 26 of Lardner's Cyclopædia (London, 1832).

POTWALLOPERS. (See Preston.)

POUDRE DE SUCCESSION (French, succession powder); poisonous powder, once prepared in Italy and France to a great extent, to kill people slowly. The horrid art of poisoning never excited more attention in France than about the year 1670,

when the extent of the crimes of the marchioness of Brinvilliers became known. A numerous society of young women, under the direction of an old woman, of the name of Hieronyma Spara, was discovered in Rome, in 1659, who had administered poison to many people among the highest classes, to rid wives of their husbands, and husbands of their wives, children of their parents, &c. The history of this foul blot in the records of mankind may be found, with many particulars of a painful interest, in Beckmann's History of Inventions, &c., translated by Johnston (vol i, division Secret Poison). Though the times when poisoning was habitually practised have past, yet, in some cases, it has, even in our times, been carried to an inconceivable extent. In 1831, a woman of the name of Gottfried was executed in Bremen, Germany, for having successively poisoned more than thirty persons (among whom were her parents, children, husbands, friends, servants), by means of butter mixed with arsenic, used to poison mice.

POUGENS, Marie Charles Joseph de, a French poet, born at Paris, in 1755, was the son of a great person at court, and, while yet a youth, attempted an imitation of Gessner's Idyls, in a poem which he called L'Aurore. Being designed for a diplomatic career, he was sent to Italy, with the consent of the king, and with letters of recommendation from a prince of the blood to cardinal Bernis. Here, in 1777, he projected his great work Trésor de la Langue Française, on the plan of Johnson's dictionary. An attack of the small pox, in his twenty-fourth year,deprived him forever of his sight; yet he continued his researches, and was sent to England as a public agent. The revolution deprived him of his pension of 10,000 livres, and, after attempting to gain a subsistence by translations, he entered the book trade, without capital or experience. His persevering industry, however, soon placed him at the head of a large establishment; but several bankruptcies nearly involved him in complete ruin, from which he was saved by a loan of 12,000 francs from a distinguished benefactress, and a further loan of 40,000 francs from Bonaparte, then first-consul, who afterwards, on his repayment of half of that sum, granted him the remainder outright. In 1808, he retired from business, and has since lived, devoted to study and his friends, at the estate of a benefactress in the valley of Vauxbuin, near Soissons. Of his numerous works we may mention Récréation de

Philosophie et de Morale; Essai sur les Antiquités du Nord, &c.; Archéologie Française, ou Vocabulaire de Mots anciens Tombés en Désuetude (2 vols., 1823); Les Quatre Ages, a poem; Abel, ou les Trois Frères; Jocko, sur l'Instinct des Animaux (1824); La Religieuse de Nimes; Lettres sur divers Sujets de Morale (1824). In 1819, he published a specimen of his Trésor, and was soon after received into several foreign academies. Pougens was, in 1806, appointed by the empress mother of Russia her literary correspondent; and he afterwards held the same appointment from the late prince Constantine.

POUGHKEEPSIE, in New York, is situated on the east shore of the Hudson, seventy-five miles south of Albany, and seventy-four north of New York. There are five landings, with convenient storehouses, wharves, &c., and the trade is extensive. On the south line of the township is the small post village called New Hamburgh. Barnegat is the name of a place on the shore of the river, where great quantities of lime are manufactured. The trade at the landings employs many packets. The village of Poughkeepsie is situated on a plain nearly a mile from the river, on the post-road from New York to Albany. It contains the county buildings, five meeting-houses, a bank, an academy, and several factories. Many of the buildings are of stone, but the new ones are of wood or brick. Population in 1820, 5726; in 1830, 7222.

POULTICES. (See Cataplasms.) Mustard poultices are called sinapisms. (q. v.)

POUNCE; gum sandarach, pounded and sifted very fine, to rub on paper, in order to preserve it from sinking, and to make it more fit to write upon. Pounce is also charcoal dust, enclosed in a piece of muslin, or some other open stuff, to be passed over holes pricked in a work, in order to mark the lines or designs on paper, silk, &c., placed underneath, which are to be afterwards finished with a pen and ink, a needle, or the like.

POUND; an English weight, of different denominations, as avoirdupois, troy, apothecaries', &c. The pound avoirdupois is sixteen ounces of the same weight, but the other pounds are each equal to twelve ounces. The pound avoirdupois is to the pound troy as 5760 to 69994, or nearly as 576 to 700. (See Measures.)-Pound is also the highest denomination used by the English in their money accounts, being equal to twenty shillings.

POURSUIVANT, or PURSUIVANT, in heraldry; the lowest order of officers at arms.

himself to rural sketches, and became one of the greatest masters of landscape upon record. He practised his art with great distinction in various parts of Italy, but chiefly in Rome, where he lived a life of celibacy, and freely expended his gains in hospitable attentions to his friends. He worked with extreme celerity, although nothing can exceed the beauty of his scenery and the precision of his perspective. He particularly excelled in the representation of land-storms, in which every tree seems agitated, and every leaf in motion. In his figures he was less happy, and they were frequently supplied by Nicholas. This skilful artist, whose performances are deemed very valuable, died, according to D'Argenville, in 1675, and to others in 1663; but the former date is preferred. He engraved eight of his own landscapes.

POWDER OF SUCCESSION. (See Poudre de Succession.)

POWER, in arithmetic and algebra; that which arises by the successive multiplication of any number or quantity into itself, the degree of the power being always denominated by the number of equal factors that are employed: thus,

2 = 2', 1st power of 2. 2 × 2 2', 2d power, or square. 2 × 2 × 2 2', 3d power, or cube. Hence it appears, that the index which denotes the degree of any power, is always equal to the number of factors from which that power arises; or one more than the number of operations. (See Exponent, and Involution.)

POWER, in law, is an authority which one man gives to another to act for him; and it is sometimes a reservation which a person makes in a conveyance for himself to do some acts, as to make leases or the like; thus, power of attorney, an instrument or deed whereby a person is authorized to act for another, either generally, or in a specific transaction. POWER, in mechanics, denotes any force, whether of a man, a horse, a spring, the wind, water, &c., which, being applied to a machine, tends to produce motion; also, any of the six simple machines, viz. the lever, the balance, the screw, the wheel and axle, the wedge, and the pulley. (See Mechanics, and Horse Power.)

POWER LOOMS are driven by water or steam, and are now universally introduced into cotton and woollen manufactories.

POWER OF A GLASS, in optics, is, by some, used for the distance between the convexity and the solar focus.

POWERS, GREAT, OF EUROPE; a term of modern diplomacy, by which are meant England, France, Austria, Prussia and Russia.

POWHATAN; a famous sachem, of great authority among the Indian tribes in Virginia, at the period of its colonization. He was father of the celebrated Pocahontas.' (q. v.)

POWNALL, Thomas, born at Lincoln in 1722, became secretary to the commissioners for trade and plantations in 1745, and had a situation in the commissariat of the army in Germany. In 1753, he went to America, and in 1757 was appointed governor of Massachusetts bay, and, subsequently, of South Carolina. He remained there till 1761, 'when, returning to England, he was nominated directorgeneral of the office of control, with the rank of colonel. He died at Bath, April 25, 1805. Governor Pownall was a fellow of the society of antiquaries, and a contributor to the Archæologia. He was also the author of Descriptions of Antiquities of the Provincia Romana of Gaul (1788, 4to.); Descriptions of Roman Antiquities dug up at Bath (4to.); Observations on the Currents in the Atlantic Ocean (1787, 4to.); and Intellectual Physics (4to.); besides many political tracts, as the Administration of the Colonies (London, 4th edition, 1768).

POYAIS; a fertile tract of land, on the Mosquito shore, near the bay of Honduras, with a capital of the same name, inhabited by a warlike race of Indians (the Poyais), who have hitherto maintained their independence. Sir Gregor Mac-Gregor, a British officer, who served with reputation in Spain, was afterwards (1816) active in the Venezuelan revolution, and, in 1817, took possession of Amelia island, on the coast of Florida (then belonging to Spain), calling upon the inhabitants to embrace the cause of independence. In 1819, he attacked Porto Bello, which he captured, but was soon after surprised in his bed, and obliged to escape out of a window. Some years after, he settled among the Poyais, and gained their confidence to such a degree as to be chosen their cacique. He encouraged commerce, founded schools, &c. In 1824, the cacique of Poyais procured a loan in London, from respectable houses. The chief production of his dominions is indigo; they also yield sugar, coffee, cocoa, tobacco, mahogany wood, dye-stuffs, &c.-See the Sketch of the Mosquito Shore, including the Territory of Poyais (Edinburgh, 1824), by Strangeway, aid to the cacique.