our Indian tribes the name of the white man's to the coasts of England. Many plants which foot. The leaves are all radical, oval, and petio- have yet appeared to be confined to one district, late, and from amongst them arise several long may be accessible to the cultivation of other re cylindrical spikes of greenish inconspicuous flow-gions, were a favorable wind, or the hand of the ers. botanist himself, to bear their seeds thither. These remarks will show how difficult it is to mark with exactness the regions of botanical geography, even supposing we were possessed of much more accurate and extensive information on the subject than we are at this moment. The anti-scorbutic and edible plants seem to be the most widely diffused throughout the earth. Such are the different varieties of cresses, celery, parsley, and scurvy-grass, which are found on every coast which has yet been visited by navigators. Many plants bearing edible berries are also of very general distribution, and form an important article of food to man. These graminea also, which are of most valuable service to man and the inferior animals, are very widely spread, although different species of them appear to thrive best in certain climates. The mosses and lichens, however, are of widest distribution. They are found in every part of the world, and in every situation. During the brief summer of the polar regions a considerable number of plants appear, particularly mosses and ferns, creeping plants, and berry-bearing bushes, such as the currant, the Rubus chamomorus and arcticus, and different species of Vaccinium, the luxuries of the Siberian and Laplander. The birch and the fir in Greenland, and along the coasts of the Icy Sea, are mere dwarfs compared with their species in the warmer countries of Europe. As the polar climate exhibits a much less variety of temperature than that of other zones, the vegetation of the frozen zones is more limited than that of any other part of the world. PLANTS. With regard to the vegetable kingdom, the principles of geographical distribution, according to climate, can be much more easily followed out. The distribution of organised beings in general depends on the three co-ordinates of latitude, longitude, and altitude. Botanists compute that, at Spitzbergen, which lies near the 80th degree N. L., there are only about 30 species of plants; in Lapland, which lies under the 70th degree, about 534; in Iceland, under the 65th parallel, about 553; in Sweden, from the southern parts of Lapland to the 55th degree, about 1300; in Brandenburg, between the 52d and 54th parallels, 2000; in Piedmont, between the 43d and 46th, 2800; nearly 4000 in Jamaica, which is between the 17th and 19th degree; and in Madagascar, situated under the Tropic of Capricorn, between the 13th and 14th degrees, more than 5000. It is true, that plants of the frigid zones are also found in the torrid; but they occur only in situations where they find a temperature as low as that of the colder zones, viz. upon high mountains. Thus the plants of Greenland and Lapland are found not only on the Alps and Pyrenees, but even on the Cordilleras. Edwards says, that while no tropical fruits grow upon the mountains of Jamaica, many European fruits thrive admirably; European Alpine plants occur on the cold mountains of Terra del Fuego; and the pine occupies the extreme limit of arborescent plants in the mountains of America, of Switzerland, and Lapland. The same physical climate, therefore, favors the growth of the same plants. If under the same climate we do not observe the same plants The diversity of climate which exists in the produced, we must attribute the difference to local temperate zones, assisted by the not less striking peculiarities, such as the quality of the soil, the diversity of soil, enables them to produce a very degree of shade, the atmosphere, and other cir- great variety of plants. Upon the boundary of the cumstances. Some plants are found universally frozen zone begins the perpetual verdure of the distributed, and are consequently adapted to every pine and the fir, which are succeeded by the apclimate; while others are confined to very limited ple, the pear, the cherry, and the plum. The more districts, beyond which they cannot be cultivated. common species of corn, such as wheat, barley, Many plants, particularly the most useful ones, oats, millet, and rye, grow every where from the may be successfully naturalized, by judicious man- tropics to the polar circles,-from the north of Afagement, in countries far distant from their origin-rica to the south of Sweden. The potato, accordal habitation, and under climates very different ng to some naturalists a native of Guiana, accordfrom that in which they were originally found. ing to others, of Chili, is now found in Siberia as Most of our fruit-trees, our corns, and edible veg-well as at the Cape of Good Hope. The species etables are of foreign extraction. Men have avail- of the genus Rosa, found in Europe, have reached ed themselves of this bountiful provision of na- us from the East Indies, China, and Japan. Euture to such a degree, that it is no longer possible rope, from the Uralian Mountains to the coast of to distinguish in all places the indigenous from Portugal, abounds with this beautiful plant. The the foreign plants. The migration of plants has roses of America have reached that continent been assisted by the sea, the wind, and granivorous through the polar lands. There are no roses in birds and quadrupeds, as well as by the hand of Australasia, nor have any species been met with man himself. Not only has man intentionally in South America; indeed, they scarcely occur transported the coffee-tree from Arabia to the any where to the south of the equator. Rice, West Indies, and the tobacco-plant from America maize, and spelt, and the finer fruits such as olives, to the shores of Europe, but even the accidental figs, capers, dates, and tamarinds, belong to the introduction of a foreign seed into a bale of mer- southern parts of this zone. The vine and the chandise, has conveyed the plants of the Brazils to mulberry occupy the space between the 30th and the fields of Lisbon, and some of these have in 50th parallels; and peaches, apricots, almonds, and their turn been transported by means as accidental | walnuts are equally injured in their growth as they approach the tropic or the polar circle. The sugar-cane and the cotton-plant, though tropical plants, are found growing far within the temperate zones. Many European plants have changed greatly under cultivation. Two hundred years ago there was only one variety of tulip-the yellow-known to florists, and there now exist upwards of 3000 varieties. cipitated on another metal, the process is called silvering. PLATINA. A metal found in Peru. It is white, but darker and not so bright as silver. It is heavier than gold, consequently the heaviest of all known bodies. Its hardness is inferior only to that of iron; and its tenacity, which is more than thirteen times that of lead, is inferior to that of iron and copper alone. Exposed to the fire, it is very nearly as fixed as gold; neither water nor air occasions any alterations in it. Platina is a metal valuable for its great hardness, the high polish of which it is susceptible, and its unalterability. It will not tarnish in the air, neither will it rust. It can be forged and extended into thin plates; and when dissolved in aqua regia, it may be made to The richest and most beautiful vegetation belongs to the torrid zone, which possesses not only the finer plants of the temperate zones, but many magnificent specimens of the vegetable kingdom peculiar to itself. In addition to its own kinds of corn, such as durra, poa, several species of polcus, cambri, kebru, and solam, it possesses the greatest variety of delicate fruits, the strongest spices, and the richest perfumes. To the plants peculiar to this zone belong the palin tribe, the pisang, bread-assume an infinite diversity of colors. fruit, cacao, vanilla, indigo, the pine-apple, the nutmeg, ginger, camphire, cassava, cinnamon, and cloves, the most beautiful cabinet-woods, and the most valuable medicinal plants. The nearer we approach to the equator, we find -"bolder hues And richer sweets, beyond our gardens' pride.' PLASTER. In pharmacy, is defined to be an external application, of a harder consistence than our ointments: these are to be spread according to the different circumstances of the wound, place, or patient, either upon linen or leather. PLATOON. In the military art, a small square body of forty or fifty men, drawn out of a battalion of foot, and placed between the squadrons of borse, to sustain them; or in ambuscades, straits, and defiles, where there is not room for whole battalions or regiments. Platoons are also used when they form the hollow-square, to strengthen the angles. The grenadiers are generally posted in platoons. PLEBEIAN, PLEBIUS. A person of the rank of the populace, or common people. The term is chiefly used in speaking of the ancient Romans; who were divided, about the time of Tarquin's expulsion, into senators, knights, and plebians, or The plebians were those who could not claim their descent from the ancient senators, appointed by Romulus, and the kings who succeeded him. PLATING. The art of covering baser metals with a thin plate of silver. It is said to have been invented by a spur-maker, not for show, but a pur-commons. pose of real utility. The more elegant spurs were used to be made of solid silver; and from the flexibility of that metal, they were liable to be bent into inconvenient forms by the slightest accident. To remedy this defect, the workman alluded to, who resided at Birmingham, contrived to make a pair of spurs hollow, and to fill the space with a slender rod of steel or iron. Finding this a great improvement, and being desirous to add cheapness to utility, he contrived to make the hollow larger, and, of course, the iron thicker, til at length he discovered the means of coating an iron spur with silver, in such a manner as to make it equally elegant with those which were made wholly of that metal. The invention was quickly applied to other purposes; and numberless vessels have now the strength and cheapness of copper or iron, with the appearance of silver. The silver plate is generally made to adhere to the baser metal by means of solder. The solder is of two kinds, the soft and hard, or tin and silver. The former of these consists of tin alone; the latter, usually, of three fourths of silver with one of brass. The plate is first fitted to the article to be plated, by means of the hammer, and afterward fastened by melting the solder. FRENCH PLATING, the burnishing leaf-silver on a piece of metal, prepared by heating to a certain degree. PLEDGE, OR PAWN. A species of bailment, being the deposit or placing of goods as security for the payment of money borrowed, or the fulfilment of an obligation or promise. It is distinguished from a mortgage of chattels, by the circumstance that the legal property in the chattel mortgaged is in the mortgagee, whereas the legal ownership of goods pawned remains in the pawner, though, according to the definition of a pawn and pledge, the pawnee not only has the right of possession, but must be in possession. If the money is not paid at the time stipulated, the pawn may be sold by the pawnee, who may retain enough of the proceeds to pay the debt intended to be secured. In some cases the terms of the deposit are the forfeiture of the pawn in case the pawner does not fulfil the promise or obligation to guaranty which the pawn is given. PLOUGHING. In rural economy, denotes the stirring and turning over of land with the plough. This is one of the most essential operations in the culture of the earth, and requires to be performed with the greatest care. Whatever, therefore, may be the design of the farmer, or the desMETAL PLATING, the joining copper and silver tination of the ground, thus moved, it ought never together, so that the copper appears on one side, to be ploughed in a wet state; because the soil and the silver on the other. cannot be improved by such labor. Farther, the When silver is dissolved in aqua-fortis, and pre-plough ought to be carried to a considerable depth into the soil; and, if one turning be not sufficient, | it will be advisable to pass another plough over the same furrow, so that the land may be effectually stirred; when, being thus exposed to the air, its fertilizing properties will not only be considerably augmented, but all perennial weeds will be completely eradicated. Deep ploughing, however, is unnecessary for land that has been recently manured with lime or marl, but, on exhausted soils, it is uncommonly beneficial, and has, therefore, been generally recommended by the most skilful husbandmen. Ploughing increases the food of plants; as it opens the soil for the reception of vegetable aliment from the air and light; and, the surface being consequently enlarged, a greater portion of land is thus exposed to its influence. Farther, by breaking up the ground, if it be too solid, and rendering it firm, in case it be too light, this operation greatly tends to improve the earth; and, as weeds and other vegetable substances are thus reduced to a state of putrefaction, it promotes the nourishment of the new roots. Lastly, ploughing removes too great humidity, by forming the land into small ridges, and contributes to the eradication of weeds, as it first causes their seeds to vegetate, and afterwards tearing up the young plants, exposes their roots to the drought, in consequence of which they are deprived of their vegetative power. PNEUMATICS. That part of natural philosophy, which treats of the mechanical properties of elastic fluids. In its original sense, it expresses a quality of air, or, more properly, of breath. Now, it has happened, in many languages, that the term used to express breath, has been also one of the terms used to express the animating principle, and even the soul; and it is to prevent confusion of this kind, that philosophers have agreed to appropriate the term pneumatics to the science of the mechanical properties of air, and the term pneumatalogy to the science of the properties of the thinking principle. There is this difference between pneumatics and hydrostatics; that whereas the former considers fluids as far as regards their elasticity, and hydrostatics their absolute property of fluidity or liquidity. PNEUMATICS, HISTORY OF. Although the ancients did not investigate the properties of air with the same minuteness as the moderns have done, yet the subject evidently engaged the attention of Aristotle and other Grecian philosophers. Aristotle was aware of the gravity of the air, and observed that a bladder filled with air would weigh more than the same bladder when empty; and Empedocles ascribed the cause of respiration to the weight of the air, which, by its pressure, insinuates itself into the lungs. Its elasticity also, as well as its gravity, must have been known and PLUMBAGO. An ore of a shining blue black made the subject of experiments, if it be true, as color, a greasy feel, and tuburculated when frac-is related by historians, that Hero of Alexandria, tured. It is by many erroneously taken for molyb-and Ctesibius, his contemporary, invented air-guns. dena, from which it is easily distinguished by its The subject was, however, for a long time neglectfracture, that of the latter being always lamel-ed, or treated superficially; for the effects which lated. PLUMBERY. The art of casting and working plumbum, or lead. This metal melis speedily, and with little heat, and is, therefore, easily cast into figures of any kind; but the chief business of plumbery is the making sheets and pipes of lead for various purposes in building. are now known to arise from the gravity and elasticity of the air were for a long time attributed to the imaginary principle of a Fuga Vacui, or Nature's abhorrence of a vacuum, a principle which Galileo did not altogether discard, although he was fully aware of the gravity of the air, and pointed out two methods of demonstrating it by weighing the air in bottles; but the pressure of the atmosSheets and other flat articles of lead are cast on phere was first discovered by Torricelli, and cleara table spread with sand; and if figures or letters ly demonstrated by an experiment, which terminaare to be raised on the surface, they are first im-ted in the invention of the barometer in 1643. It pressed upon the sand. Leaden pipes are made hollow by being cast upon a core or round rod of brass or iron. PLUSH. In commerce, &c. a kind of stuff having a sort of velvet kuap, or shag, on one side, composed regularly of a woof of a single woollen thread and a double warp, the one wool, of two threads twisted, the other goat's or camel's hair; though there are some plushes entirely of worsted, and others composed wholly of hair. Plush is manufactured, like velvet, on a loom with three treadles; two of these separate and depress the woollen warp, and the third raises the hair warp, upon which the workman throwing the shuttle, passes the woof between the woollen and hair warp; and afterwards laying a brass broach, or needle, under that of the hair, he cuts it thereon with a knife destined for that use; conducting the knife on the broach, which is made a little hollow all its length, and thus gives the surface of the plush an appearance of velvet. occurred to him, on observing that a column of water, 34 feet high, is sustained above its level in the tube of a common pump, that the same force, whatever that was, would sustain a column of any other fluid which weighed as much as that column of water on the same base; and hence he concluded that quicksilver, being about 14 times as heavy as water, would not be sustained at a greater height than 29 or 30 inches. Accordingly he took a glass tube of several feet in length, and, having sealed it hermetically at one end, he filled it with quicksilver; then, inverting it, he held it upright, and, keeping his finger against the open or lower orifice, he immersed that end in a vessel of quicksilver, and, on withdrawing his finger, he found that the quicksilver, according to his expectation, descended till the column of it was about 30 inches above that in the open vessel; whence he was led to infer that it could be no other than the weight of the atmosphere incumbent on the external surface of the quicksilver, which counterbalanced the fluid in the tube, and thus introduced the principle that the air had not only weight, but that its weight|clared, that if the cruel sentence was executed, the was the cause of the suspension of water in pumps, first blow should fall on her. and of the quicksilver in the tube. This principle, after repeated experiments from the philosophers in France, England, and Germany, became established, and that of the vacuum was finally exploded. From this time they proceeded to be more ininute in their investigations, and Father Mersenne, who was the first philosopher in France that was apprized of Torricelli's experiment, set about determining the specific gravity of air, which he made to be as 1 to 400; but Mr. Boyle, by a more accurate experiment, came to a nearer result, and made it to be to that of water in the proportion of 1 to 938, and Mr. Hawksbee succeeded, after repeated experiments, in obtaining the proportion of 1 to 885. Experiments were made by others in the winter as well as the summer, and the medium of all is about 1 to 832. As to the elasticity of the air, which also became the subject of experiment, it was shown that, with moderate pressure, it is always proportional to the density, and that the density is always as the compressing force; whence also the elasticity of air is as the force by which it is compressed. In consequence of these investigations into the mechanical properties of the air, not only was the barometer invented, and the air-gun revived, but other pneumatic machines were contrived, as the air-pump, air-balloon, thermometer, &c.; of which a more particular account will be found under their respective heads. POCAHONTAS. Perhaps they, who are not particularly acquainted with the history of Virginia, may be ignorant that Pocahontas, an Indian princess, was the protectress of the English, and often screened them from the cruelty of her father. She was but twelve years old, when captain Smith, the bravest, the most intelligent, and the most humane, of the first colonists, fell into the hands of the savages. He already understood their language, had traded with them several times, and often appeased the quarrels between the Europeans and them. Often had he been obliged also to fight them and punish their perfidy. At length, however, under the pretext of commerce, he was drawn into an ambush, and the only two companions who accompanied him fell before his eyes; but though alone, by his dexterity, he extricated himself from the troop which surrounded him; until, unfortunately, imagining he could save himself by crossing a morass, he stuck fast; so that the savages, against whom he had no means of defending himself, at last took and bound him, and brought him to Powhatan. The king was so proud of having captain Smith in his power, that he sent him in triumph to all the tributary princes, and ordered that he should be splendidly treated, till he returned to suffer that death which was prepared for him. The fatal moment at length arrived. Captain Smith was laid upon the hearth of the savage king, and his head placed upon a large stone to receive the stroke of death, when Pocahontas, the youngest and darling daughter of Powhatan, threw herself upon his body, clasped him in her arms, and de All savages (absolute sovereigns and tyrants not excepted) are invariably more affected by the tears of infancy, than the voice of humanity. Powhatan could not resist the tears and prayers of his daughter. Captain Smith consequently obtained his life on condition of paying for his ransom a certain quantity of muskets, powder, and iron utensils; but how were they to be obtained? They would neither permit him to return to James Town, nor let the English know where he was, lest they should demand him sword in hand. Captain Smith, who was as sensible as courageous, said that if Powhatan would permit one of his subjects to carry to James Town a leaf which he took from his pocket-book, he should find under a tree, at the day and hour appointed, all the articles demanded for his ransom. Powhatan consented; but without having much faith in his promises, believing it to be only an artifice of the captain to prolong his life. But he had written on the leaf a few lines, sufficient to give an account of his situation. The messenger returned. The king sent to the place fixed upon, and was greatly astonished to find every thing which had been demanded. Powhatan could not conceive this mode of transmitting thoughts; and captain Smith was henceforth looked upon as a great magician, to whom they could not show too much respect. He left the savages in this opinion, and hastened to return home. Two or three years after, some fresh differences arising amidst them and the English, Powhatan, who no longer thought them sorcerers, but still feared their power, laid a horrible plan to get rid of them altogether. His project was to attack them in profound peace, and cut the throats of the whole colony. The night of this intended conspiracy, Pocahontas took advantage of the obscurity; and, in a terrible storm, which kept the savages in their tents, escaped from her father's house, advised the English to be on their guard, but conjured them to spare her family, to appear ignorant of the intelligence she had given, and terminate all their differences by a new treaty. It would be tedious to relate all the services which this angel of peace rendered to both nations. It shall only be added, that the English, it is not known from what motives, but certainly against all faith and equity, thought proper to carry her off. Long and bitterly did she deplore her fate, and the only consolation she had was captain Smith, in whom she found a second father. She was treated with great respect, and married to a planter by the name of Rolfe, who soon after took her to England. This was in the reign of James the First; and it is said that the monarch, pedantic and ridiculous in every point, was so infatuated with the prerogative of royalty, that he expressed his displeasure, that one of his subjects should dare to marry the daughter even of a savage king. It will not perhaps be difficult to decide on this occasion, whether it was the savage king who derived honor from finding himself placed upon a level with the European prince, or the English monarch, who by his pride and prejudices, reduced himself to a level with the chief of the savages. Be that as it will, captain Smith, who had returned the wheel of a chariot, advance a notch each step, to London before the arrival of Pocahontas, was or each revolution of the wheel, so that the numextremely happy to see her again; but dared not ber being marked on the edge of the wheel the treat her with the same familiarity as at James paces may be numbered, so as to measure exactly Town. As soon as she saw him, she threw her- the distance from one place to another. Pedomeself into his arms, calling him her father; but find-ters are of various kinds: some mark the time like ing that he neither returned her caresses with equal a watch, and are accordingly worn in the pocket. warmth, nor the endearing title of daughter, she turned aside her head and wept bitterly; and it was a long time before they could obtain a single word from her. Captain Smith inquired several times what could be the cause of her affliction. "What!' said she, 'did I not save thy life in America? When I was torn from the arins of my father, and conducted amongst thy friends, didst thou not promise to be a father to me? Didst thou not assure me that if I went into thy country, thou wouldst be my father, and that I should be thy daughter? Thou hast deceived me; and behold me, now here, a stranger and an orphan.' It was not difficult for the captain to make peace with this charming creature, whom he tenderly loved. He presented her to several people of the first quality; but never dared to take her to court, from which, however, she received several favors. After a residence of several years in England, an example of virtue and piety, and attachment to her husband, she died, as she was on the point of embarking for America. She left an only son, who was married, and left none but daughters; and from these are descended some of the principal characters in Virginia. POINT. In Geometry, as defined by Euclid, is a quantity which has no parts, or which is indivisible. Points are the ends or extremities of lines. If a point is supposed to be moved any way, it will, by its motion, describe a line. POINT-BLANK. In Gunnery, denotes the shot of a gun levelled horizontally, without either mounting or sinking the muzzle of the piece. In shooting point-blank, the shot or bullet is supposed to go directly forward in a straight line to the mark; and not to move in a curve, as bombs and highly elevated random-shots do. When a piece stands upon a level plane, and is laid level, the distance between the piece and the point where the shot touches the ground first, is called the point-blank range of that piece; but as the same piece ranges more or less, according to a greater or less charge, the point-blank range is taken from that of a piece loaded with such a charge as is commonly used in action. It is, therefore, necessary that these ranges of all pieces should be known, since the gunner judges from thence what elevation he is to give to his pieces, when he is either farther from or nearer to the object to be fired at; and this he can do pretty nearly by sight, after considerable practice. POE-BIRD. In Ornithology, an inhabitant of some of the South Sea Islands, where it is held in great esteem and veneration by the natives. It POINTER. The dog called pointer is found goes by the name of kogo in New Zealand; but in Spain, Portugal and France, with but slight difit is better known by that of poe-bird. It is some- ference of form. It is not a native of England, what less than our black-bird. The feathers are but has long since been naturalized there. Those of a fine mazarine blue, except those of its neck, pointers,' says Johnson in his Shooter's Companwhich are of a most beautiful silver gray, and two ion, which I have seen direct from Spain, are or three short white ones which are on the pinion-heavy and clumsily formed; those from Portugal joint of the wing. Under its throat hang two little tufts of curled snow-white feathers, called its poies (the Otaheitian word for ear-rings ;) which occasioned the name of poe-bird being given to it. It is remarkable for the sweetness of its note, as well as the beauty of its plumage. Its flesh is also del icate food. are somewhat lighter; while the French breed is remarkable for a wide furrow which runs between the nostrils, and gives to the animal's countenance a very grotesque appearance. They are all thick and heavy, with large, chubby heads, long, pendent ears, and short, smooth hair; they are often ill tempered and snappish, and are good for little in Great Britain till they have been crossed POETRY. The art of expressing sentiments with the more generous blood of that island. in measured syllables, according to certain rules, Yet the conjunction of the setter and pointer is harmony, and taste: identified with the human by no means advisable. Excellent pointers have mind, because practised by all semi-barbarous peo- been produced by the fox-hound and the Spaniard. ple, and with improved success, as they advance In crossing with the Spanish pointer, the deepin civilisation. It is divided into blank verse and flewed hound is to be preferred, and from judicious rhyme, and denominated according to its sub-crossing excellent pointers are to be met with in ject; as pastoral for rural objects; elegiac for most parts of England. They differ from the setplaintive pieces; lyrical, or ballad; didactic, or ter, as when they have approached sufficiently instructive; satirical, or humorous; and dramatic, near the game, they stand erect, whereas the trueor conversational. bred setter will either sit upon his haunches, or lie close to the ground, generally the latter. Pointers PEDOMETER, OR PODOMETER. An in- often suffer much from sore feet. I have generalstrument in the form of a watch, consisting of va-ly found white-footed dogs much more tender in rious wheels with teeth catching in one another, all disposed in the same plane, which, by means of a chain, or string, fastened to a man's foot, or to this respect than those whose feet are of a dark color. Pointers are sometimes used with bells round their necks in cover shooting. When the |