mitted and reported many other similar tales concerning the extraordinary powers and virtues of this bird; but it is needless to recite them. Its flesh has the odour of musk, and is unpalatable. Plate II. Aves, fig. 4. ALCHEMY, that branch of chemistry which had for its principal objects the transmutation of all the metals into gold; the panacea, or universal remedy for all diseases; and the alkahest, or universal menstruum. Those who pursued these delusive projects gradually assumed the form of a sect, under the name of Alchemists, a term made up of the word chemist, and the Arabian article al as a prefix. The alchemists laid it down as a first principle, that all metals are composed of the same ingredients, or that the substances at least which compose gold exist in all metals, and are capable of being obtained from them. The great object of their researches was to convert the baser metals into gold. The substance which produced this property they called lapis philosophorum, "the philosophers' stone;" and many of them boasted that they were in possession of that grand instrument. The alchemists were established in the west of Europe as early as the ninth century; but between the eleventh and fifteenth alchemy was in its most flourishing state. The principal alchemists were Albertus Magnus, Roger Bacon, Arnoldus de Villa Nova, Raymond Lully, and the two Isaacs of Holland.

ALCHIMILLA, or ALCHEMILLA, ladies' mantle, in botany, a genus of the Tetrandria Monogynia class of plants, the calyx of which is a single-leafed perianthium: there is no corolla, nor any pericarpium; the cup finally becomes a capsule, containing a single elliptical and compressed seed. There are four species. A. vulgaris, common ladies' mantle, or beanfoot, is frequent in meadows and pastures in England. It is perennial, and flowers in June and July. Horses, sheep, and goats eat it. The great richness of the milk in the celebrated dairies of the Alps is attributed to the plenty of this plant, and that of the rib-wort plantain. The plant is astringent, and in Gothland and other places a tincture of its leaves is given in spasmodic and convulsive cases. A. alpina, cinquefoil, or alpine ladies' mantle, grows naturally in the North of England, North Wales, and in the Highlands of Scotland. It is a native of the northern parts of Europe, and is admitted into the gardens on account of its elegance. The A. pentaphyllea grows naturally on the Alps, and is found in the botanical gardens in this coun

try: it may be propagated by parting the roots in autumn. They should have a moist soil, and a shady situation.

ALCHORNEA, in botany, a genus of the Monadelphia Octandria class and order, of which there is but a single species. Male, calyx three, five-leaved; corolla none: fe male, calyx five-toothed; corolla none; styles two-parted.

ALCOHOL, a term applied by chemists to the purely spirituous part of liquors that have undergone the vinous fermentation. It is in all cases the product of the saccharine principle, and is formed by the successive processes of vinous fermentation and distillation. Various kinds of ardent spirits are known in commerce, as brandy, rum, &c.; but they differ in colour, taste, smell, &c. The spirituous part, however, is the same in each, and may be procured in its purest state by a second distillation, which is termed rectification. See DISTILLATION, FERMENTATION, and RECTIFICATION. Alcohol is procured most largely in this coun try from a fermented grain-liquor; but in France and other wine countries, the spirit is obtained from the distillation of wine, hence the term spirit of wine. See BRANDY. Alcohol is a colourless, transparent liquor, appearing to the eye like pure water. It possesses a peculiar penetrating smell, distinct from the proper odour of the distilled spirit from which it is procured. To the taste it is excessively hot and burning; but without any peculiar flavour. From its lightness, the bubbles which are formed by shaking subside almost instantaneously, which is one method of judging of its purity. Alcohol may be volatilized by the heat of the hand. It is converted into vapour at the temperature of 55° of Fahrenheit, and it boils at 165°. It has never been frozen by any degree of cold, natural or artificial, and on this account it has been much used in the construction of thermometers. Alcohol mixes with water in all proportions, and during the mixture heat is extricated, which is sensible to the hand. At the same time there is a mutual penetration of the parts, so that the bulk of the two liquors when mixed is less than when separate: consequently the specific gravity of the mixture is greater than the mean specific gravity of the two liquors taken apart. Alcohol is supposed to consist of

Its uses are many and important: it is employed as a solvent for those resinous gums which form the basis of numerous varnishes: it is employed also as the basis of artificial cordials and liquors, to which a flavour and additional taste are given by particular admixtures: it serves as a solvent for the more active parts of vegetables, under the form of tinctures. The antiseptic power of alcohol renders it particularly valuable in preserving particular parts of the body as anatomical preparations. The steady and uniform heat which it gives during combustion, makes it a valuable material for burning in lamps.

ALCORAN, or ALKORAN, the name of a book held equally sacred among the Mahometans as the bible is among Christians.

The word alcorun properly signifies reading; a title given it by way of eminence, just as we call the Old and New Testament Scriptures.

That Mahomet was the author of the Alcoran is allowed both by Christians and the Mahometans themselves; only the latter are fully persuaded that it was revealed to him by the ministry of the angel Gabriel; whereas the former, with more reason, think it all his own invention, assisted by one Sergius, a Christian monk. The Alcoran is held not only of divine original, but eternal and uncreated, remaining, as some express it, in the very essence of God. The first transcript has been from everlasting by God's throne, written on a table of vast bigness, in which are also recorded the divine decrees, past and future. A copy from this table, in one volume, on paper, was sent down to the lowest heaven, in the month of Ramadan, on the night of power. From whence it was delivered out to Mahomet by parcels, some at Mecca, and some at Medina. Though he had the consolation of seeing the whole once a year, and in the last part of his life twice. Ten new chapters were delivered entire, the greater part only in separate periods, which were written down from time to time by the prophet's amanuensis, in this or that part, of this or the other chapter, as he directed, The first parcel that was revealed, was the five first verses of the ninety-sixth chapter, which the prophet received in a cave of Monnt Harah, near Mecca.

The general aim of the Alcoran was, to unite the professors of the three different religions then followed in Arabia, Idolaters, Jews, and Christians, in the knowledge and worship of one God, under the sanction of certain laws, and the outward signs of ceremonies, partly of ancient, and partly of novel

institution, enforced by the consideration of rewards and punishments, both temporal and eternal, and to bring all to the obedience of Mahomet, as the prophet and ambassador of God, who was to establish the true religion on earth, and be acknowledged chief pontiff in spiritual matters. The chief point therefore inculcated in the Alcoran is the unity of God, to restore which, the prophet confessed was the chief end of his mission. The rest is taken up in prescribing necessary laws and directions, frequent admonitions to moral and divine virtues, the worship and reverence of the Supreme Being, and resignation to his will.

As to the book itself, as it now stands, it is divided into 114 Suras, or chapters, which are again divided into smaller portions or verses. But besides these divisions, Maho metan writers farther divide it into 60 equal portions, called hiz, or hazah; each of which they subdivide into four parts.

After the title at the head of each chapter, except the ninth, is prefixed the formula, "In the name of the most merciful God," called by the Mahometans Bismallah, wherewith they constantly begin all their books and writings, as the distinguishing mark of their religion.

Twenty-nine of the chapters of the Alcoran have this further peculiarity, that there are certain letters of the alphabet prefixed to them. In some a single letter; in others, two or more. These letters are supposed, by the true believers, to conceal divers profound mysteries, the understanding whereof has been communicated to no man, their prophet excepted. Yet some have pretended to find their meaning, by supposing the letters to stand for so many words, expressing the names, attributes, and works of God; others explain these letters from the organ made use of in their pronunciation; others from their value in numbers.

There are seven principal editions of the Koran, two at Medina, one at Mecca, one at Cufa, one at Bassora, one in Syria, and the common or vulgate edition. The first contains 6000 verses; the second and fifth, 6214; the third, 6219; the fourth, 6236; the sixth, 6226; and the last, 6225; but the number of words and letters is the same in all, viz. 77,639 words, and 323,015 letters.

The Alcoran is allowed to be written with the utmost elegance and purity of language, in the dialect of the Koreishites, the most noble and polite of all the Arabians, but with some mixture of other dialects. It is the standard of the Arabic tongue, and as the orthodox believe, and are taught by the

book itself, inimitable by any human pen; and therefore insisted on as a permanent miracle, greater than that of raising the dead, and alone sufficient to convince the world of its divine original; and to this miracle did Mahomet himself chiefly appeal, for the confirmation of his mission, publicly challenging the most eloquent schoolmen in Arabia, to produce a single chapter comparable to it. A late ingenious and candid writer, who is a very good judge, allows the style of the Alcoran to be generally beautiful and fluent, especially where it imitates the prophetic manner, and scripture phrase; concise, and often obscure; adorned with bold figures, after the eastern taste; enlivened with florid and sententious expressions; and, in many places, especially where the majesty and attributes of God are described, sublime and magnificent.

To the pomp and harmony of expression some ascribe all the force and effect of the Alcoran; which they consider as a sort of music, equally fitted to ravish and amaze, with other species of that art. In this Mahomet succeeded so well, and so strangely captivated the minds of his audience, that several of his opponents thought it the effect of witchcraft and enchantment, as he himself complains.

So numerous are the commentaries on the Alcoran, that a catalogue of their bare titles would make a volume: we have a very elegant translation of it into English by Mr. Sale; who has added a preliminary discourse, with other occasional notes, which the curious may consult on this head.

Among Mahometans this book is held in the greatest reverence and esteem. The Mussulmen dare not touch it without being first washed, or legally purified; to prevent which an inscription is put on the cover or label: "Let none touch it but they who are clean." It is read with great care and respect. They swear by it, take omens from it on all weighty occasions, carry it with them to war, write sentences of it on their banners, adorn it with gold and precious stones, and do not suffer it to be in the possession of any who hold a different religion.

ALCYON, in natural history, a name given to the kingsfisher. See ALCEDO.

ALCYONIUM, in natural history, a genus of Zoophytes, the characters of which are, that the animal grows in the form of a plant; the stem or root is fixed, fleshy, gelatinous, spongy, or coriaceous, with a cellular epidermis, penetrated with stellated pores, and shooting out tentaculated ovipa

rous hydra. There are 28 species. From some experiments made by Mr. Hatchett, and related by him in the Phil. Trans. on several of the species of alcyonium he was led to conclude, that they were all composed of a soft, flexible, membranaceous substance, slightly hardened by carbonate, mixed with a small portion of phospate of lime.

ALDEBARAN, in astronomy, a star of the first magnitude, called in English the Bull's eye, as making the eye of the constellation Taurus.

ALDER-tree, the English name of a genus of trees, called by botanists alnus. See ALNUS.

ALDERMAN, in the British policy, a magistrate subordinate to the mayor of a city, or town-corporate.

The number of these magistrates is not limited, but is more or less according to the magnitude of the place. In London they are twenty-six; each having one of the wards of the city committed to his care. Their office is for life; so that when one of them dies or resigns, a ward-mote is called, who return two persons, one of whom the lord mayor and aldermen choose to supply the vacancy.

ALDROVANDA, in botany, a genus of the Pentantria Pentagynia class and order, of which there is only one species, viz. the A. vesiculosa, found in marshes in Italy and India, with bladders like utricularia, but in bunches.

ALE-conner, an officer in London, who inspects the measures of public houses. They are four in number, and chosen by the common-hall of the city.

ALE-houses, no licence to be granted to any person unless he produce a certificate of his good character, under the hands of the clergyman, churchwardens, &c. Penalties for selling without a licence, unless at fairs, 40s. for the first offence, 41. for the second: no person can sell wine to be drank at his own house, who has not an ale licence.

ALE-silver, a tax paid yearly to the lord mayor of London, by all who sell ale within the city.

ALECTRA, in botany, a genus of the Didynamia Angiosperma class and order, of which there is a single species only, viz. A. capensis, a native of the Cape of Good Hope; found in grassy places near rivers; flowering in November and December.

ALEMBERT (JOHN LE ROND D') an emineut French mathematician and philoso pher, and one of the brightest ornaments of the 18th century. He was perpetual

toils and plagues himself all his life, that people may talk of him when he is dead."

He received his first education among the Jansenists, in the College of the Four Nations, where he gave early signs of genius and capacity. In the first year of his philosophical studies, he composed a Commentary on the Epistle of St. Paul to the Romans. The Jansenists considered this production as an omen that portended to the party of Port-Royal, a restoration to some part of their former splendor, and hoped to find one day in d'Alembert a second Pascal. To render the resemblance more complete, they engaged their pupil in the study of the mathematics; but they soon perceived that his growing attachment to this science was likely to disappoint the hopes they had formed with respect to his future destination: they therefore endeavoured to divert him from the pursuit; but their endeavours were fruitless.

On his quitting the college, finding himself alone, and unconnected in the world, he sought an asylum in the house of his nurse, who was the wife of a glazier. He hoped that his fortune, though not ample, would enlarge the subsistence, and better the condition of her family, which was the only one that he could consider as his own. It was here, therefore, that he fixed his residence, resolving to apply himself entirely to the study of geometry. And here he lived, during the space of 30 years, with the greatest simplicity, discovering the augmentation of his means only by increasing displays of his beneficence, concealing his growing reputation and celebrity from these honest people, and making their plain and uncouth manners the subject of good-natured pleasantry and philosophical observation. His good nurse perceived his ardent activity; heard him mentioned as the writer of many books; and beheld him with a kind of compassion: "You will never," said she to

As D'Alembert's fortune did not far exceed the demands of necessity, his friends advised him to think of some profession that might enable him to increase it. He accordingly turned his views to the law, and took his degrees in that faculty, which he soon after abandoned, and applied himself to the study of medicine. Geometry, however, was always drawing him back to his former pur suits; so that after many ineffectual struggles to resist its attractions, he renounced all views of a lucrative profession, and gave himself up entirely to mathematics and poverty. In the year 1741 he was admitted a member of the Academy of Sciences; for which distinguished literary promotion, at so early an age (24), he had prepared the way by correcting the errors of the "Analyse Demontrée" of Reyneau, which was highly esteemed in France in the line of analytics He afterwards set himself to examine, with attention and assiduity, what must be the motion and path of a body, which passes from one fluid into another denser fluid, in a direction oblique to the surface between the two fluids. Two years after his election to a place in the academy, he published his "Treatise on Dynamics." The new prin ciple developed in this treatise consisted in establishing an equality, at each instant, between the changes that the motion of a body has undergone, and the forces or powers which have been employed to produce them; or, to express the same thing otherwise, in separating into two parts the action of the moving powers, and considering the one as producing alone the motion of the body, in the second instant, and the other as employed to destroy that which it had in the first.

So early as the year 1744, D'Alembert had applied this principle to the theory of the equilibrium, and the motion of fluids: and all the problems before resolved in physics, became in some measure its corollaries. The discovery of this new principle was followed by that of a new calculus, the first essays of which were published in a "Discourse on the General Theory of the Winds;" to this the prize-medal was adjudged by the Academy of Berlin, in the year 1746, which proved a new and brilliant addition to the fame of D'Alembert. This new calculus of "Partial Differences" he applied, the year following, to the problem of vibrating chords, the resolution of which, as well as the theory

of the oscillations of the air, and the propagation of sound, had been but imperfectly given by the mathematicians who preceded him; and these were his masters or his rivals. In the year 1749 he furnished a method of applying his principle to the motion of any body of a given figure. He also resolved the problem of the precession of the equinoxes; determining its quantity, and explaining the phenomenon of the nutation of the terrestrial axis discovered by Dr. Bradley.

In 1752, D'Alembert published a treatise on the "Resistance of Fluids," to which he gave the modest title of an "Essay;" though it contains a multitude of original ideas and new observations. About the same time he published, in the Memoirs of the Academy of Berlin, "Researches concerning the Integral Calculus," which is greatly indebted to him for the rapid progress it has made in the present century.

While the studies of D'Alembert were confined to mere mathematics, he was little known or celebrated in his native country. His connections were limited to a small society of select friends. But his cheerful conversation, his smart and lively sallies, a happy method at telling a story, a singular mixture of malice of speech with goodness of heart, and of delicacy of wit with simplicity of manners, rendering him a pleasing and interesting companion, his company began to be much sought after in the fashionable circles. His reputation at length made its way to the throne, and rendered him the object of royal attention and beneficence. The consequence was a pension from govern. ment, which he owed to the friendship of count D'Argenson.

But the tranquillity of D'Alembert was abated when his fame grew more extensive, and when it was known beyond the circle of his friends, that a fine and enlightened taste for literature and philosophy accompanied his mathematical genius. Our author's eulogist ascribes to envy, detraction, &c. all the opposition and censure that D'Alembert met with on account of the famous Encyclopédie, or Dictionary of Arts and Sciences, in conjunction with Diderot. None surely will refuse the well-deserved tribute of applause to the eminent displays of genius, judgment, and true literary taste, with which D'Alembert has enriched that great work. Among others, the Preliminary Discourse he has prefixed to it, concerning the rise, progress, connections, and affinities of all the branches of human knowledge, is perVOL. I.

haps one of the most capital productions the philosophy of the age can boast of.

Some time after this, D'Alembert published his "Philosophical, Historical, and Philological Miscellanies." These were followed by the "Memoirs of Christiana, Queen of Sweden;" in which D'Alembert shewed that he was acquainted with the natural rights of mankind, and was bold enough to assert them. His " Essay on the Intercourse of Men of Letters with Persons high in Rank and Office," wounded the former to the quick, as it exposed to the eyes of the public the ignominy of those servile chains which they feared to shake off, or were proud to wear. A lady of the court hearing one day the author accused of having exaggerated the despotism of the great, and the submission they require, answered slyly, "If he had consulted me, I would have told him still more of the matter."

D'Alembert gave elegant specimens of his literary abilities in his translations of some select pieces of Tacitus. But these occupations did not divert him from his mathematical studies: for about the same time he enriched the Encyclopédie with a multitude of excellent articles in that line, and composed his "Researches on several Important Points of the System of the World," in which he carried to a higher degree of perfection the solution of the problem concerning the perturbations of the planets, that had several years before been presented to the Academy. In 1759 he published his " Elements of Philosophy:" a work much extolled as remarkable for its precision and perspicuity. The resentment that was kindled (and the disputes that followed it) by the article GENEVA, inserted in the Encyclopédie, are well known. D'Alembert did not leave this field of controversy with flying colours. Voltaire was an auxiliary in the contest: but as he had no reputation to lose, in point of candour and decency; and as he weakened the blows of his enemies, by throwing both them and the spectators into fits of laughter, the issue of the war gave him little uneasiness. It fell more heavily on D'Alembert; and exposed him, even at home, to much contradiction and opposition. It was on this occasion that the late King of Prussia offered him an honourable asylum at his court, and the office of president of his academy: and the king was not offended at D'Alembert's refusal of these distinctions, but cultivated an intimate friendship with him during the rest of his life. He had refused, some time before this, a proposal made by the Empress

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