native of Carolina, where it becomes a large tree. The shoots of this sort grow very strong in Britain, and are generally angular; with a light green bark like the willow. The leaves on young trees, and also those on the lower shoots, are very large, almost heart-shaped, and crenated; but those upon the older trees are smaller as the trees advance, their bark becomes lighter, approaching to a grayish color. It may be propagated by cuttings or layers; but the last is the method generally practised, and the plants raised by it are less moist than others. The shoots of this tree, while young, are frequently killed down to a considerable length by the frost in winter; but, as the trees grow older, their shoots are not so vigorous, and become more ligneous, so are not liable to the same disaster. But the trees should be planted in a sheltered situation; for, as their leaves are very large, the wind has great power over them; and the branches being tender, they are frequently broken or split by the winds in summer, when they are much exposed. This species grows very quickly, and the wood is beautiful.

3. P. Canadensis, the liard, is a large tree, the wood light, not easy to be split, and fit for several

uses.

4. P. fastigata, the Italian or Lombardy poplar, is said by M. Fougeroux de Bondaroy to be of very little value; but M. Dambourney says it is excellent for dyeing. See No. 9.

5. P. major, the white poplar, has its leaves rounder than the first, and not much above half their size they are indented on their edges, and are downy on their under side, but not so white as those of the former, nor are their upper surfaces of such a deep green color.

6. P. nigra, the black poplar, has oval heartshaped leaves, slightly crenated on their edges; they are smooth on both sides, and of a light green color. It is less apt to take root from large truncheons; therefore it is best to plant cuttings of it about a foot and a half in length, thrusting them a foot deep in the ground. This sort will grow almost on any soil, but will thrive best in moist places. The inner bark is used by the inhabitants of Kamtschatka as a material for bread; and paper has sometimes been made of the cottony down of the seeds. The roots dissolve into a kind of gelatinous substance, and are coated over with a tubular crustaceous spar, called by naturalists osteocolla, formerly imagined to have some virtue in producing the callus of a fractured bone. See OSTEOCOLLA.

7. P. tacamahaca, grows naturally in Canada and other parts of North America. This is a tree of a middling growth, but sometimes grows to thirty feet high, sending out on every side many short thick shoots, which are covered with a light brown bark, garnished with leaves differing from one another in shape and size; most of them are almost heart-shaped; but some are oval, and others nearly spear-shaped; they are whitish on their under side, but green on their upper. The buds are covered with a glutinous resin, which smells very strong, and is the gum tacamahaca of the shops. The best, called, from its being collected in a kind of gourd-shells, tacamahaca in shells, is somewhat unctuous and

softish, of a pale yellowish or greenish color, an aromatic taste, and a fragrant delightful smell approaching to that of lavender or ambergris. This sort is very rare; that commonly found in the shops is in semitransparent globes or grains, of a whitish, yellowish, brownish, or greenish color, of a less grateful smell than the foregoing. This resin is said to be employed externally by the Indians for discussing and maturating tumors, and abating pains in the limbs. It is an ingredient in some anodyne, hysteric, cephalic, and stomachic plasters; but the fragrance of the finer sort sufficiently points out its utility in other respects. The tacamahaca sends up a great number of suckers from its roots, by which it multiplies in plenty; and every cutting which is planted will take root.

8. P. tremula, the aspen tree, has roundish, angularly indented leaves: they are smooth on both sides, and stand on long foot-stalks, and so are shaken by the least wind; whence it has the title of the trembling poplar, or aspen tree.

9. P. Virginiana, the Virginia poplar, affords a wood of excellent quality, that may be applied to many uses. All these trees may be propagated either by layers or cuttings, as also from suckers which the white poplars send up from their roots in great plenty. The best time for transplanting these suckers is in October, when their leaves begin to decay. These may be placed in a nursery for two or three years, to get strength before they are planted out where they are designed to remain; but, if they are propagated from cuttings, it is better to defer that until February, when truncheons of two or three feet long should be thrust about a foot and a half into the ground. These will readily take root; and, if they be planted in a moist soil, they will arrive at a considerable bulk in a few years. From some experiments, made by M. Dambourney, it appears that the poplar may be usefully employed in dyeing. The Italian poplar gives a dye of as fine a lustre, and equally durable, as that of the finest yellow wood, and its color is more easily extracted. It is likewise very apt to unite with other colors in composition. Besides the populus fastigata, M. Damnbourney tried also the Nigta, the Virginiana, the Canadensis, the alba, and the tremula; and found that all these dyed wool of a nut-color, fawn-color (vigogne), Nankin, musk, and other grave shades, according to the quantity of wood employed, and the length of time it was boiled.

POQUELIN. See MOLIERE.

PORANA, in botany, a genus of the monogynia order, and pentandria class of plants. The corolla is campanulated; the calyx is quinquefid, and larger than the fruit; the style semibifid, long, and permanent; the stigmata globular; the perianthium bivalved.

PORCELAIN, n. s. Fr. porcelaine; barb. Lat. porcellus, said to be derived from pour cent années; because it was believed by Europeans, that the materials of porcelain were matured under ground 100 years. China; china ware. See below.

We have burials in several earths, where we put divers cements, as the Chinese do their porcelain.

Bacon.

PORCELAIN is a fine kind of earthenware, chiefly manufactured in China, and thence sometimes called China-ware. All earthen wares which are white and semitransparent are also called porcelains: but among these, great differences are so evident, that even persons who are not connoisseurs in this way, prefer much the porcelain of some countries to that of others. The word porcelain is clearly of European derivation; as the Chinese language has no such sounds. Some derive it from porcelana, which in Portuguese signifies a cup. Porcelain is called in China tsé-ki. The first porcelain seen in Europe was brought from Japan and China. The first European porcelains were made in Saxony and in France; and afterwards in England, Germany, and Italy: but, as all these were different from the Japanese, so each of them had its peculiar character. The finest and best porcelain of China is made in a village called King-te-ching, in the province of Kiang-si. This celebrated village (as they call it, for the villages of China are larger than the cities of Europe), is a league and a half in length, and contains, we are assured, a million of inhabitants. The workmen, invited by the attracting allurements of the European trade, have established manufactories also in the provinces of Fokien and Canton; but this porcelain is not esteemed. It is not known who first found out the art of making porcelain, nor is the date of the invention recorded. But it is certain that the manufacture has been carried on in King-te-ching at least since A. D. 442, if not long before that period. F. D'Entrecolles, a Romish missionary, gives an account of the method of making porcelain, of which Grosier has an abridgment, in his General Description of China, as follows: The principal ingredients of the fine porcelain are pe-tun-tse and kao-lin, two kinds of earth from the mixture of which the paste is produced. The kao-lin is intermixed with small shining particles; the other is purely white, and very fine to the touch. These first materials are carried to the manufactories in the shape of bricks. The pe-tun-tse, which is so fine, is nothing else but fragments of rock taken from certain quarries, and reduced to powder. Every kind of stone is not fit for this purpose. The color of that which is good, say the Chinese, ought to incline a little towards green. A large iron club is used for breaking these pieces of rock they are afterwards put into mortars; and, by means of levers, headed with stone bound round with iron, and moved by manual labor or by water, they are reduced to a very fine powder. The dust afterwards collected is thrown into a arge vessel full of water, which is strongly stirred with an iron shovel. When it has been

The

left to settle for some time, a kind of cream rises on the top, about four inches in thickness, which is skimmed off, and poured into another vessel filled with water: the water in the first vessel is stirred several times; and the cream which arises is still collected, until nothing remains but the coarse dregs, which precipitate: these dregs are carefully collected, and pounded anew. With regard to what is taken from the first vessel, it is suffered to remain in the second until it is formed into a kind of crust at the bottom. When the water above it seems quite clear, it is poured of by gently inclining the vessel, that the sediment may not be disturbed; and the paste is thrown into large moulds proper for drying it. Before it is entirely hard, is divided into small square cakes, which are sold by the hundred. kao-lin, which is used in the composition of porcelain, requires less labor than the pe-tun-tse. Nature has a greater share in the preparation of it. There are large mines of it in the bosoms of certain mountains, the exterior strata of which consist of a kind of red earth. These mines are very deep, and the kao-lin is found in small lumps, that are formed into bricks after having gone through the same process as the pe-tun-tse. It is from the kao-lin that fine porcelain derives all its strength. The Chinese have also discovered a substance proper to be employed in the composition of porcelain. It is a stone, or rather a species of chalk, called hoa-che, from which the physicians prepare a kind of draught that is said to be detersive, aperient, and cooling. It is glutinous, and has a resemblance to scap. Porcelain made with hoa-che is very rare, and much dearer than any other. It has an exceedingly fine grain, and, with regard to the painting, if it be compared with that of the common porcelain, it appears to surpass it much. This por celain is, besides, so light, that it surprises those who are accustomed to handle other kinds; it is also much more brittle: it is very difficult to ca upon the proper degree of tempering it. Ho che is seldom used in forming the body of the work; the vessel is plunged when dry, that it may receive a coat before it is painted and varnished. But Hoa-che, when washed, pounded, and dissolved in water, is alone sufficient to make porcelain; and is used instead of kao-lin; but it is much dearer.

To pe-tun-tse and kao-lin, the two principal elements, must be added the oil or varnish from which it derives its splendor and whiteness. This oil is of a whitish color, and is extracted from the same kind of stone which produces the pe tun-tse, but the whitest is always chosen, and that which has the greenest spots. The oil is obtained from it by the same process used in making the pe-tun-tse. To 100 lbs. of its cream is added one pound of che-kao, a mineral something like alum, which is put into the fire till it becomes red hot and then pounded. This mineral is a kind of runnet, and gives a consistence to the oil, which is however carefully preserved in its state of fluidity. The oil thus preserved is never employed alone, another oil must be mixed with it, which is extracted from lime and fern ashes, to 100 lbs. of which is also added a pound of che-kao. When these two oils are mixed, they must be equally thick. With regard to the quan

bly necessary to be employed, it is usual to mix ten measures of stone oil with one measure of the oil made from lime and fern ashes. The first labor consists in again purifying the pe-tun-tse and the kao-lin. The workmen then proceed to mix these two substances together. For fine porcelain they put an equal quantity of the kaolin and the pe-tun-tse; for the middling sort they use four parts of the kao-lin and six of the petun-tse. The least quantity put of the former is one part to three of the pe-tun-tse. When this mixture is finished, the mass is thrown into a large pit, well paved and cemented in every part; it is then trod upon, and kneaded until it becomes hard. From this mass, thus prepared, the workmen detach different pieces which they spread out upon large slates where they knead and roll them in every direction, carefully observing to leave no vacuum in them, and to keep them free from the mixture of any extraneous body. A hair or a grain of sand would spoil the whole work. When this paste has not been properly prepared, the porcelain cracks, and melts or becomes warped." All plain works are fashioned with the wheel. When a cup has undergone this operation, the outside of its bottom is quite round. The first work man gives it the requisite height and diameter, this cup then passes to a second workman, who forms its base; soon after a third applies it to his mould, and gives it a proper form; a fourth polishes it with a chisel, and the last work man fashions its bottom with a chisel. Some vases thus pass, with astonishing dexterity and expedition, through the hands of seventy persons. Large works are executed in parts which are fashioned separately. When all the pieces are finished, and almost dry, they are put together and cemented with paste made of the same substance, and softened with water. Some time after the seams are polished with a knife, both without and within; and, when the vessel is covered with varnish, the least trace of them is not to be seen. In this manner, spouts, handles, rings, and other parts are added; and embossed works, grotesque images, figures of trees, animals, busts, &c., are brought to perfection. With regard to those flowers and ornaments which are not in relief, they are either engraven or imprinted with a stamp. Ornaments in relief prepared separately are also added to pieces of porcelain, almost in the same manner as lace is put upon a coat.

After a piece of porcelain has been properly fashioned, it then passes into the hands of the painters. These heapei, or painters, are very little acquainted with the rules of drawing; all their skill being acquired by practice, though some of them display taste and genius. The labor of painting, in these manufactories, is divided among a great number of hands. One is entirely employed in tracing out the first colored circle, which ornaments the brims of the vessel; another designs the flowers, and a third paints them; one delineates waters and mountains, and another birds and other animals; human figures are worst executed. The tsou-you, which is a kind of oil procured from white flint, has the peculiar property of making those pieces of porcelain upon which it is laid appear to be covered

with an infinitude of veins in every direction; at a distance one would take them for cracked vases, the fragments of which have not been displaced. The color communicated by this oil is a white, somewhat inclining to that of ashes. If it be laid upon porcelain, entirely of an azure blue, it will appear in the same manner to be variegated with beautiful veins. This kind of porcelain is called tsoui-ki. The Chinese make vases also ornamented with a kind of fret-work, perforated in such a manner as to resemble a very fine lace. In the middle is placed a cup proper for holding any liquid; and this cup makes only one body with the former, which appears like a lace wrapped round it. The Chinese workmen had formerly the secret of making a still more singular kind of porcelain: they painted upon the sides of the vessel fishes, insects, and other animals, which could not be perceived until it was filled with water. This secret is in a great measure lost; the following part of the process, is, however, preserved :-The porce. lain, which the workmen intend to paint in this manner, must be extremely thin and delicate. When it is dry, the color is laid on pretty thick, not on the outside, as is generally done, but on the inside. The figures painted upon it, for the most part, are fishes, as being more analogous to the water with which the vessel is filled. When the color is thoroughly dry, it is coated over with a kind of size, made with porcelain earth; so that the azure is entirely enclosed between two lamine of earth; when the size becomes dry, the workman pours some oil into the vessel, and afterwards puts it upon a mould and applies it to the lath. As this piece of porcelain has received its consistence and body within, it is made as thin on the outside as possible, without penetrating to the color; its exterior surface is then dipped in oil, and when dry it is baked in a common furnace. The art of making these vases requires the most delicate care, and a dexterity which the Chinese perhaps do not at present possess. They have, however, from time to time, made several attempts to revive the secret of this magic painting, but their success has been very imperfect. This kind of porcelain is known by the name of kia-tsing, or pressed azure. After the porcelain has received its proper form, its color, and all the intended ornaments, it is put into the furnace. Each piece, however inconsiderable it may be, is enclosed in an earthen case or box. In the bottom of these boxes is put a layer of fine sand, which is covered over with powder of the kao-lin, to prevent the sand from adhering too closely to the bottom of the vessel. The piece of porcelain is then placed upon this bed of sand, and pressed gently down, that the sand may take the form of the bottom of the vessel, which does not touch the sides of its case the case has no cover. A second prepared in the same manner, and containing its vessel, is fitted into the first, so that it entirely shuts it, without touching the porcelain which is below; and thus the surface is filled with piles of cases, which defend the pieces they contain from the too direct action of the fire. Small pieces, such as tea cups, &c., are enclosed in cases about four inches high, and sprinkled with the dust of the

kao-lin, and placed in piles. These different piles are placed very closely in the furnace; they support each other mutually by pieces of earth which bind them at the top, bottom, and middle, but in such a manner that a free passage is left for the flame to insinuate itself everywhere around them. Before each of these furnaces for baking porcelain there is a long porch, which conveys air, and supplies in certain respects the place of a bellows. They were formerly six feet high and six long; but they are now two fathoms in height, and almost four in breadth; and the sides and roof are so thick that one may lay the hand upon them without being incommoded by the heat. The dome or roof is shaped like a funnel, and has a large aperture at the top, through which clouds of flame and smoke incessantly issue. Besides this principal aperture, there are five others smaller, which are covered with broken pots, but in such a manner that the workmen can increase or diminish the heat according as it may be found most convenient: through these also he is enabled to discover when the porcelain is sufficiently baked. Having uncovered that hole which is nearest the principal aperture, he takes a pair of pincers and opens one of the cases: if he observes a bright fire in the furnace, if all the cases are red-hot, and if the colors of the porcelain appear with full lustre, he judges that it is in a proper state; he then discontinues the fire, and entirely closes up the mouth of the furnace for some time. In the bottom of the furnace there is a deep hearth about two feet in breadth, over which a plank is laid, that the workmen may enter to arrange the porcelain. When the fire is kindled on this hearth, the mouth of the furnace is immediately closed up, and an aperture is left only sufficient for the admission of faggots about a foot in length, but very narrow. The furnace is first heated for a day and night; after which two men keep continually throwing wood into it, and relieve each other by turns: 180 loads are generally consumed for one baking. As the porcelain is burning hot, the workman employs for the purpose of taking it out long scarfs or pieces of cloth, which are suspended from his neck. The Chinese divide their porcelain into several classes, according to its different degrees of fineness and beauty. The whole of the first is reserved for the emperor.

The celebrated Reaumur first considered porcelain scientifically, and submitted the fruits of his investigations to the Academy of Sciences, in two memoirs, in 1727 and 1729. He endeavoured to investigate the internal structure of different kinds of porcelain; and for that purpose procured broken pieces of the French, Saxon, and Japanese porcelains. Upon examining the difference of their grains (the technical term among potters for their internal structure), he found the Japanese to be fine, close, compact, moderately smooth, and somewhat shining. The French porcelain of St. Cloud had a grain far less close and fine than the Japanese; not shining, or but very little, and resembling the grain of sugar. The grain of the Saxon kind was found more compact than either; not graulous, but smooth and shining like enamel.

Finding such considerable differences in the grain, he next examined them by fire, which discovered properties still more essentially distinct By a violent heat the French and Saxon porce lains were melted, but the Japanese withstood the power of the most violent fire he could excite. This difference between European and Japanese porcelain suggested to our author that, as all porcelains somewhat resemble glass in consis tence and transparency, they must be semivitrifications, though they are less compact, and much less transparent. He next made experiments upon the oriental porcelain, and, having exposed the Chinese Kao-lin and pe-tun-ise to a very violent fire, he discovered that the latter fused without addition, but that the former gave no signs of fusibility whatever. He afterwards mixed them, and made cakes of them, which by baking he converted into porcelain, resembling that of China.

He farther discovered that the pe-tun-tse of the Chinese was a hard stone of the vitrifiable kind, but much more fusible than any of the kind known in Europe; and that the kaolin was a talky substance, reduced to a very fine powder. He afterwards attempted to make porcelain like that of the Chinese with materials found in France; but from some cause, not fully explained, he was unsuccessful in this as well as in some other experiments. He, however, in the course of these made a discovery of a process for converting common glass to a peculiar kind of porcelain, to which he gave his name, which he published in 1739. He rendered glass of a milky color, semitransparent, so hard as to strike fire with steel, infusible, and of a fibrous grain, by means of cementation. The process, which he published, is not difficult. Common glass, such as that of which wine bottles are made, succeeds best. The glass vessel which is to be converted into porcelain is to be enclosed in a baked earthen case or seggar. The vessel and case are to be filled with a cement composed of equal parts of sand and powdered gypsum of plaster; and the whole is to be put into a potter's kiln, and to remain there during the baking of common earthenware; after which the glass vessel will be found transformed into such a matter as has been described. See POTTERY and STAF FORDSHIRE.

PORCH, n. s. Fr. parche; Lat. porticus. A roofed entrance before a door; any entrance. Ehud went forth through the porch, and shut the doors of the parlour. Judges iii. 23.

All this done,

Repair to Pompey's porch, where you shall find us. Shakspeare.

Not infants in the porch of life were free, The sick, the old, that could but hope a day Longer by nature's bounty, not let stay. Ben Jonson

A PORCH, in the ancient architecture, was a vestibule, or a disposition of insulated columns usually crowned with a pediment, forming a covert place before the principal door of temple or court of justice. When a porch had four columns in front it was called a tetrastyle; when six, hexastyle; when eight, octostyle, &c.

PORCH, Gr. σroa, in antiquity, was a public portico in Athens adorned with the pictures of

Polygnolus and other eminent painters. It was in this portico that Zeno the philosopher taught; and hence his followers were called Stoics. See STOIC and ZENO.

PORCIA, a sister of Cato the younger, highly commended by Cicero.

PORCIA, a daughter of Cato the younger, remarkable for prudence, philosophy, courage, and conjugal tenderness. She married first Bibulus, and after his death the celebrated Marcus Brutus. She gave herself a deep wound in the thigh, and, on Brutus asking the reason, she said she wished to try if she had fortitude to bear pain, and courage to share his secrets. Brutus, astonished at her fortitude, told her of the conspiracy against Cæsar. Porcia wished him success, and kept the secret, but dreaded the event, and swooned away the day Brutus went to the assassination of Cæsar; and, when he killed himself, she followed his example.

PORCIUS. See CATO.

PORCO, a province of Buenos Ayres, commences on the west side of the town of Potosi, from which it extends twenty leagues. From its elevated situation, there is a scarcity of fruits and grain, but in the valleys the soil is fruitful, and the breeds of sheep are considerable. Such as the vicunna and the guanaco, native breeds. In this province is the mountain of Porco, from which the incas of Peru drew their silver; and it was the first mine worked by the Spaniards. The mines still produce great quantities of that metal. Population 22,000.

PORCUPINE, n. s. Fr. porc espi, or epic; Ital. porcospino; Lat. porcus epinus. A kind of hedge-hog.

This stubborn Cade

PORCUPINE, in zoology. See HYSTRIX. PORCUPINE MAN, the name by which one Edward Lambert, who had a distempered skin, went in London. An account of him will be found in the Philosophical Transaction for 1755, by Henry Baker, F. R. S.

PORCUPINE RIVER, a river of North America, so called by captains Lewis and Clarke, from the number of porcupines found near it: it falls into the Missouri from the north, and is a bold and beautiful stream, 112 yards wide, though the water is only forty yards at its entrance. Captain Clarke ascended it several miles, and passed it above where it enters into the high lands.

It

is about 2000 miles from the confluence of the Missouri with the Mississippi. Also a river of the United States, in the north-west territory which runs into Lake Superior. Long. 88° W., lat. 46° 14' N.

PORE, n. s. POROUS, adj. PO'ROUSNESS, n. 8. PO'RINESS, POROSITY.

Fr. pore; Lat. porus; Gr. Topoç. A spiracle or hole; particularly a spiracle of the skin; passage of perspiration: porous,

porousness, poriness, porosity, follow this sense. Witches, carrying in the air, and transforming themselves into other bodies, by ointments, and anointing themselves all over, may justly move a man to think that these fables are the effects of imagination; for it is certain that ointments do all, if laid on any thing thick, by stopping of the pores, shut in the vapours, and send them to the head exBacon. tremely.

This is a good experiment for the disclosure of the rosity and which a grosser. nature of colours; which of them require a finer po

Id.

Vultures and dogges have torne from every limb His porous skin; and forth his soul is fled.

Pores are small interstices between the particles of matter, which constitute every body, or between certain aggregates or combinations of them. Quincy.

I took off the dressings, and set the trepan above the fractured bone, considering the poriness of the bone below. Wiseman.

PORE, v. n. Gr. Topog is the optic nerve; but I imagine pore to come by corruption from some English word,' says Dr. Johnson. It is, in fact, the Span. ojar, perojar (a barb. Lat. oculare). To look with great intenseness and care; to examine with great attention.

All delights are vain; but that most vain, Which, with pain purchased, doth inherit pain; As painfully to pore upon a book, To seek the light of truth, while truth the while Doth falsely blind the eye-sight. Shakspeare.

Poreblind men see best in the dimmer light, and likewise have their sight stronger near at hand than those that are not poreblind, and can read and write smaller letters; for that the spirits visual in those that are poreblind are thinner and rarer than in others and therefore the greater light disperseth them.

Bacon's Natural Histo y.

A book was writ, called Tetrachordon,

The subject new: it walked the town a while Numbering good intellects; now seldom pored on.

Milton. the same thing. The ey grows weary with poring perpetually on Dryden's Dufresnoy.

Let him with pedants hunt for oraise in books, Pore out his life amongst the lazy gownmen, Grow old and vainly proud in fancied knowledg

Rows