Monogynia class and order. Natural order, Bicornes; Rhododendra, Jussieu. Essential character, corolla bell-shaped; stamina inserted into the receptacle; capsule fivecelled. There are seven species. A. pontica much resembles the rhododendron ponticum, but it has five stamens and yellow corollas, not ten stamens and violet-coloured corollas as that has. The leaves are smaller, ovate, and ciliate: a native of Pontus. A. indica is a shrub three feet in height, with a trunk an inch thick, having a rough cinereous brown bark; the branches are short, twisted and irregular; leaves stiff villose, close and evergreen; beautiful bright red flowers cover the whole upper part of the shrub. Native of the East Indies; much cultivated in Japan for the elegance of its flowers, and the variety in their size and colours. A. viscosa is a low shrub rising with several slender stems nearly four feet high. The leaves come out in clusters at the ends of the shoots, without order: the flowers come forth in clusters between the leaves, and have the appearance of those of the honeysuckle, and are as agreeably scented. They appear in the middle of July, but do not bring forth seeds in Eng. land. The Pontic and Indian species have not yet been cultivated in Europe. The viscosa grows naturally in shade, and upon moist ground in most parts of North Ameica, from whence many of the plants have been sent of late years to England, and several of them have produced their beautiful flowers. They must have a moist soil, and a shady situation, otherwise they will not thrive; they can only be propagated by shoots from their roots, and laying down their branches. The best time for laying down the young shoots is at Michaelmas, and if they are covered with some old tan to keep out the frost, it will be of great use to them.

AZIMUTH, in astronomy, an arch of the horizon, intercepted between the meridian of the place and the azimuth, or vertical circle passing through the centre of the object, which is equal to the angle of the zenith formed by the meridian and verticle circle: or it is found by this proportion. As the radius to the tangent of the latitude of the place, so is the tangent of the sun's or star's altitude, for instance, to the co-sine of the azimuth from the south, at the time of the equinox.

AZIMUTH, magnetical, an arch of the horizon, intercepted between the azimuth, or vertical circle passing through the centre of

any heavenly body, and the magnetical meridian.

This is found by observing the object with an azimuth compass.

AZIMUTH compass, an instrument adapted to find, in a more accurate manner than by the common sea-compass, the sun or star's magnetical amplitude, or azimuth. It is also used to take the bearings of headlands, ships, and other objects at a distance. The azimuth compass differs from the common sea compass in this, that the circumference of the card, or box, is divided into degrees, and there is fitted to the box an index with two sights, which are upright pieces of brass placed diametrically opposite so each other, having a slit down the middle of them, through which the sun, or star, or other object is to be viewed, at the time of observation. See COMPASS.

AZIMUTH dial, one whose style or gnomon is at right angles to the plane of the horizon.

AZIMUTH circles, called azimuths, or vertical circles, are great circles of the sphere, intersecting each other in the zenith and nadir, and cutting the horizon at right angles in all the points thereof.

The horizon being divided into 360°, there are reckoned 360 azimuths.

These azimuths are represented by the rhumbs on common sea charts, and on the globe they are represented by the quadrant of altitude when screwed in the zenith. On these azimuths is reckoned the height of the stars, and of the sun when not in the meridian.

AZOTE, or nitrogen, in chemistry, a gas that forms the unrespirable part of the atmospheric air, and it exists in the proportion of about 78 per cent, by bulk, or 74 per cent in weight. The properties by which this gas was first distinguished, were principally negative, in direct opposition to those of oxygen, the other constituent of the atmosphere: the latter supporting combustion and animal life in an eminent degree, while the former was found to be immediately fatal to animals; hence its name azote, or the extinguisher of life. Oxygen also produces a great change in almost all metallic substances, which is known by the term oxydation; azote, on the contrary, not only extinguishes life and flame immediately, but produces no change whatever on combustible bodies immersed in it.

This gas is obtained by the following methods: if a quantity of iron filings and sul

phur, mixed together with a little water, be put into a glass receiver full of atmospheric air, it will in a few days absorb all the oxygen, and the remainder will be azote, or more properly azotic gas. Phosphorus may be substituted for the iron filings and sulphur, and the absorption will be completed in 24 hours. Diluted nitric acid, poured on muscular flesh, and the heat of 100° applied, will furnish azotic gas. By whatever means obtained, its properties are always the same; viz. it is invisible and elastic: it has no smell; its specific gravity is about ,98, or, according to Mr. Davy,,978; 100 cubic inches of it weighs upwards of 30 grains; it cannot be breathed by animals without instant suffocation; and it is not sensibly absorbed by water. Azote is a constituent part of all animal bodies: it is the cause of the production of ammonia; and in certain proportions with oxygen, it forms the nitric acid: according to the experiments of Mr. Davy, nitric acid is formed of

29.5 of azote

70.5 of oxygen.

The composition of nitric acid was discovered by Mr. Cavendish, and hence is explained how the putrefaction of animal matters is favourable to the production of nitre. It is from this combination that azote obtained the name of nitrogen, or the base of nitric acid: this, indeed, seems the preferable term, azote only implying the general property of destroying life, which is common to many of the other gases. Azote in its different stages of oxydation becomes nitrous oxide, nitrous gas, as well as nitric acid.

In experiments, azote is detected chiefly by its negative properties. Gas may be inferred to be azotic, if it instantly extin. guishes a taper immersed in it, and at the same time is not sensibly absorbed by water or liquid alkali; nor renders lime water turbid; which does not blacken the solutions of lead or silver; which mixes with oxygen in any proportion, without diminution, or the production of red fumes, and when so mixed, does not explode by the contact of a lighted body.

AZURE, among painters, the beautiful blue colour, with a greenish cast, prepared from the lapis lazuli, generally called ultramarine. See COLOUR.

With greater propriety, however, azure signifies that bright blue colour prepared from the lapis armenus, a different stone from the lapis lazuli, though frequently confounded together. This colour is, by our painters, commonly called Lambert's blue.

AZURE, in heraldry, the blue colour in the arms of any person below the rank of a baron. In the escutcheon of a nobleman, it is called saphire; and in that of a sovereign prince, Jupiter. In engraving, this colour is expressed by lines, or strokes drawn horizontally. This colour may signify justice, perseverence, and vigilance; when compounded with

The second letter of the alphabet,

voice by a strong and quick expression of the breath, and opening of the lips; and is therefore one of the labials; as a mute, it hath a middle power between the smooth sound of P, and the rougher sound of F

and V.

B is also used as an abbreviation: thus, in music, B stands for the tone above A, as Bb, or bB, does for B flat, or the semitone major above A: B also stands for bass, and B. C. for basso continuo, or thorough bass, As a numeral, B was used by the Greeks

and Hebrews, to denote 2; but among the (thus B) for 3000.

BABOON, the name of that tribe of apes which have short tails. See SIMIA.

BABYLONICS, in literary history, a fragment of the ancient history of the world, ending at 267 years before Christ; and composed by Berosus or Berossus, a priest of Babylon, about the time of Alexander. Babylonics are sometimes also cited in ancient writers by the title of Chaldaics. The Babylonics were very consonant with Scripture, as Josephus, and the ancient christian

chronologers assure us'; whence the author is usually supposed to have consulted the Jewish writings. Berosus speaks of an universal deluge, an ark, &c. He reckons 10 generations between the first man and the deluge, and marks the duration of the several generations by saroi, or periods of 223 lunar months; which, reduced to years, differ not much from the chronology of Moses. The Babylonics consisted of three books, including the history of the ancient Babylonians, Medes, &c. but only a few imperfect extracts are now remaining of the work, preserved chiefly by Josephus and Syncellus; where all the passages of citations of ancient authors out of Berosus are collected with great exactness. Annius, of Viterbo, kindly offered his assistance to supply the loss, and forged a complete Berosus out of his own head. The world has not thanked him for the imposture.

BABYROUSSA, in zoology, the Indian hog. See Sus,

BACCHARIS, in botany, ploughman's spikenard: of the Syngenesia Polygamia Superflua class and order. Natural order composita; compound flowers, division the third discoidea; corymbiferæ, Jussieu. Essential character; calyx imbricate, cylindric; florets, female mixed with hermaphrodites; down simple; receptacle naked. There are nine species; most of the plants are shrubby; the flowers are disposed commonly in corymbs.

BACHELOR, or BATCHELOR, a man who still continues in the state of celibacy, or who was never married, and who, in certain cases, is subject to a double tax.

BACHELOR was anciently a denomination given to those who had attained to knighthood, but had not a number of vassals sufficient to have their banner carried before them in the field of battle; or, if they were not of the order of bannerets, were not of age to display their own banner, but obliged to march to battle under another's banner. It was also a title given to young cavaliers, who having made their first campaign, received the military girdle accordingly. And it served to denominate him who had overcome another in a tournament, the first time he ever engaged.

BACHELORS, knights, were so called, as being the lowest order of knights, or inferior to bannerets.

BACHELORS, in an university sense, are persons that have attained to the bacca-laureat; or who have taken the first degree in the liberal arts and sciences. Before a perVOL. I.

son can be admitted to this degree at Oxford, it is necessary that he study there four years; three years more may entitle him to the degree of master of arts; and in seven' years more he may commence bachelor of divinity. At Cambridge the degrees are usually taken much the same as at Oxford, excepting in law and physic, in either of which the bachelor's degree may be taken in six years. In France, the degree of bachelor of divinity is attained in five years study, that is, in two years of philosophy, and three of divinity.

BACHELOR, in music, one who has taken his first degree in music. A qualification formerly required of a candidate for this honour, was the being able to read and expound certain books in Boethius, a Greek writer in the science, of the sixth century. It is now required of the candidate, to compose an exercise for voices and instruments, in six parts, which exercise must be publicly performed in the music-school, or other place in the university.

BACILLARIA, in natural history, a genus of insects of the order Infusoria. Generic character: body consisting of cylindrical straw-like filaments, placed parallel to each other, and frequently changing their position. There is but a single species noticed by Gmelin, viz. B. paradoxa, foundon the ulva latissima; body composed of linear, yellowish, short filaments, united together, forming themselves into a square. zigzag, or extended line, but always preserving their parallelism and resting in a square.

BACK, in brewing, a large flat vessel in which the wort is put to stand and cool before boiling. The ingredients of beer pass through three kinds of vessels; they are mashed in one, worked in another, and cooled in a third, called backs or coolers."

BACK gammon, an ingenious game played with dice and tables, to be learned only by observation and practice.

However, the following rules concerning it cannot fail to be acceptable to our readers. In the first place, the men, which are thirty in number, being equally divided between the two gamesters, are placed thus, viz. two on the ace point, five on the side of your left hand table, three on the cinque, and five on the ace point of your right hand table, which are answered on the like points by your adversaries men; or they may be disposed thus, viz. two on the ace point, five on the double sice or sice-cinque point, three on the cinque point in your own tables, and

Gg

five on the sice point at home; which are to be answered by your adversary.

The men being thus disposed be sure to make good your trey and ace points; hit boldly, and come away as fast as you can.

When you come to a bearing have a care of making when you need not; and doublets now will stand you most in stead. If both bear together, he that is first off, without doublets, wins one; if both bear, and one goes off with doublets, he wins two. If your table be clear before your adversary's men are come in, that is back-gammon, which is three; but if you thus go off with doublets, it is four.

The great dexterity of this game is to be forward, if possible, upon safe terms; and so to point the men that it shall not he possible for the adversary to pass, though you have entered your men, till you give him liberty, after having got two to one of the advantage of the game.

BACK staff, in the sea language, an instrument formerly used for taking the sun's altitude at sea: so called because the back of the observer is turned towards the sun during the observation.

BACK stays of a ship, are ropes belonging to the main-mast and fore-mast, and the masts belonging to them; serving to keep them from pitching forwards or over-board.

BACKING, in law, a warrant of justice of peace, where a warrant granted in one jurisdiction is required to be executed in another; as where a felony has been committed in one county and the offender resides in another; in which case, on proof of the hand-writing of the justice who granted the warrant, a justice in such other county indorses or writes his name at the back of it, thereby giving authority to execute the warrant in such other county.

BACON (ROGER), in biography, an Eng lish monk of the Franciscan order, celebrated for his genius and learning, was born near Ilchester in Somersetshire, in the year 1214. He commenced his studies at Oxford; from whence he removed to the university of Paris, which at that time was esteemed the centre of literature: here he made such progress in the sciences, that he was esteemed the glory of the university, and was in high estimation with several of his countrymen, particularly with Robert Groothead, or Grouthead, afterwards Bishop of Lincoln, his great friend and patron. Having taken the degree of doctor, he took the habit of the Franciscan order, either while he was in France, or soon after, his return to England, about the year

1240. He now pursued his favourite study of experimental philosophy with unremitting ardour and assiduity. In this pursuit, in experiments, instruments, and in scarce books, he informs us he spent, in the course of 20 years, no less than 2000l. which sum was generously furnished to him by some of the heads of the university, to enable him the better to pursue his noble researches. But such extraordinary talents, and progress in the sciences, which in that ignorant age were so little known to the rest of mankind, while they raised the admiration of the more intelligent, could not fail to excite the envy of his illiterate fraternity, whose malice he further drew upon him by the freedom with which he treated the clergy in his writings, in which he spared neither their ignorance nor their want of morals: these therefore found no difficulty in possessing the vulgar with the notion of Bacon's dealing with the devil. Under this pretence he was restrained from reading lectures; his writings were confined to his convent; and at length, in 1278, he himself was imprisoned in his cell, at 64 years of age. Being allowed, however, the use of his books, he still proceeded in the rational pursuit of knowledge, correcting his former labours, and writing several curious pieces.

When Bacon had been ten years in confinement, Jerom de Ascoli, general of his order, who had condemned his doctrine, was chosen pope by the name of Nicholas IV.; and being reputed a person of great abilities, and one who had turned his thoughts to philosophical studies, Bacon resolved to apply to him for his discharge; and to shew both the innocence and the usefulness of his studies, addressed to him a treatise "On the Means of avoiding the infirmities of Old Age." What effect this had on the pope does not appear; it did not at least produce an immediate discharge: however, towards the latter end of his reign, by the interposition of some noblemen, Bacon obtained his liberty; after which he spent the remainder of his life in the college of bis order, where he died in the year 1294, at 80 years of age, and was buried in the Franciscan church. Such a are the few particalars which the most diligent researches have been able to discover concerning the life of this very extraordinary man.

Bacon's printed works are: 1, "Epistola Fratris Røgeri Baconis de Secretis Operibus Artis et Naturæ, et de Nullitate Magiæ:" Paris, 1542, in 4to. Basil, 1593, in 8vo.

2. "Opus Majus:" London, 1733, in folio, published by Dr. Jebb. 3. "Thesaurus Chemicas:" Francf. 1603 and 1620. These printed works of Bacon contain a considerable number of essays; but there remain also in different libraries several manuscripts not yet published.

His other physical writings shew no less genius and force of mind. In his treatise "Of the Secret Works of Art and Nature," he shews that a person perfectly acquainted with the manner observed by nature in her operations would be able to rival her. In another piece, "Of the Nullity of Magic," he points out, with great sagacity and penetra tion, whence the notion of it sprung, and how weak all pretences to it are. From a perusal of his works, it is evident that Bacon was no stranger to many of the capital discoveries of the present and past ages. Gunpowder he certainly knew: thunder and lightning, he tells us, may be produced by art: for that sulphur, nitre, and charcoal, which when separate have no sensible effect, when mixed together in due proportion, and closely confined, and fired, yield a loud report. A more precise description of gunpowder cannot be given in words. He also mentions a sort of unextinguishable fire prepared by art: which proves that he was not unacquainted with phosphorus: and that he had a notion of the rarefaction of the air, and the structure of an air-pump, is past contradiction. He was the miracle, says Dr. Freind, of the age in which he lived, and the greatest genius, perhaps, for mechanical knowledge, that ever appeared in the world since Archimedes. He appears likewise to have been a master in the science of optics: he has accurately described the uses of reading-glasses, and shewn the way of making them. Dr. Freind adds, that he also describes the camera obscura, and all sorts of glasses which magnify or diminish any object, or bring it nearer to the eye, or remove it farther off. Bacon says himself, that he had great numbers of burning-glasses: and that there were none ever in use among the Latins, till his friend Peter de Mahara Curia applied himself to the making of them. That the telescope was not unknown to him, appears from a passage where he says, that he was able to form glasses in such a manner, with respect to our sight and the objects, that the rays shall be refracted and reflected wherever we please, so that we may see a thing under what angle we think proper, either near or at a distance, and be able to read the smallest letters at

an incredible distance, and to count the dust and sand, on account of the greatness of the angle under which we see the objects: and also that we shall scarce see the greatest bodies near us, on account of the smallness of the angle under which we view them. His skill in astronomy was amazing: he discovered that error which occasioned the reformation of the calendar; one of the greatest efforts, according to Dr. Jebb, of human industry: and his plan for correcting it was followed by Pope Gregory the Thirteenth, with this variation, that Bacon would have had the correction to begin from the birth of our Saviour, whereas Gregory's amendment reaches no higher than the Nicene council.

On the whole, it cannot be doubted that Friar Bacon is justly entitled to everlasting remembrance, as a philosopher and truly great man. If knowledge, says Dr. Enfield, is now too far advanced for the world to derive much information from his writings, respect must nevertheless be paid to the memory of the man who knew more than his contemporaries, and who in a dark age added new lights to the lamp of science.

BACON (FRANCIS), in biography, Baron of Verulam, Viscount of St. Albans, and Lord High Chancellor of England under King James I. He was born in 1560, being son of Sir Nicholas Bacon, Lord Keeper of the Great Seal in the reign of Queen Elizabeth, by Ann daughter of Sir Anthony Cook, eminent for her skill in the Latin and Greek languages. He gave even in his infancy tokens of what he would one day become; and Queen Elizabeth had many times occasion to admire his wit and talents, and used to call him her young lord keeper. In his thirteenth year he was entered a student at Trinity College, Cambridge, where he studied the philosophy of Aristotle, and made such progress in his studies, that at sixteen years of age he had run through the whole circle of the liberal arts as they were then taught, and even began to perceive those imperfections in the existing philosophy, which he afterwards so effectually exposed, and thence not only overturned the tyranny which prevented the progress of true knowledge, but laid the foundation of that free and useful philosophy which has since opened a way to so many glorious discoveries. On his leaving the university, his father sent him to France; where, before he was 19 years of age, he wrote a general view of the state of Europe: but Sir Nicholas dying, he was obliged suddenly to return to England, where he applied himself to the