on plains, the work of the tread-mill, under proper restrictions as to duration, must be as natural and healthful as any other. Its effects have now proved it to be so. As animal power is exhausted exactly in proportion to the time during which it is acting, as well as in proportion to the intensity of force exerted, there may often be a great saving of it by doing work quickly, although with a little more exertion during the time. Suppose two men of equal weight to ascend the same stair, one of whom takes only a minute to reach the top, and the other takes four minutes; it will cost the first but a little more than a fourth part of the fatigue which it costs the second, because the exhaustion has relation to the time during which the muscles are acting. The quick mover may have exerted, perhaps, one twentieth more force in the first instant, to give his body the greater velocity which was afterwards continued; but the sloth supported his load four times as long. A healthy man will run rapidly up a long stair, and his breathing will scarcely be quickened at the top; but, if he walk up slowly, his legs will feel fatigued, and he will have to wait some time before he can speak calmly. For the same reason, coach-horses are much spared by being made to gallop up a short hill, and being then allowed to go more slowly for a little time, so as to rest at the top. The rapid waste of muscular strength, which arises from continued action, is shown by keeping the arm extended horizontally for some time: few can continue the exertion beyond a minute or two. In animals which have long horizontal necks, there is a provision of nature in a strong elastic substance on the back, or upper part of the neck, which nearly supports the head, independently of muscular exertion. ANISETTE. (See Liqueur.) ANNOTTA. (See Arnatto.) ANSPACH, MARGRAVINE OF. (See Craven, Lady.) ANTIOCH, ERA OF. (See Epoch.) ANTOMMARCHI; physician of Napoleon at St. Helena. He is a native of Corsica, who left a professorship of anatomy in Florence, in order to attend the exiled emperor. Cardinal Fesch offered him a pension; but he refused it. He attended the emperor till his last moments; and a legacy of 100,000 francs was left him in his will. He was also charged, in the same, to open the body; but sir Hudson Lowe would not permit it. After his return to Europe, he published, in 1825, Paris, a description of Napoleon's last mo ments. This work, as well as those of O'Meara and Las Cases, are important contributions to the history of the empe ror. Antommarchi afterwards practised medicine in Paris, and completed his beautiful but very expensive anatomical plates, which he had previously com. menced with Morgagni in Florence. When Poland was visited by the horrors of war, he hastened thither, leaving his lucrative practice and scientific labors. With considerable trouble he reached Warsaw, where the national governmen gave him the direction of the medical establishments. Still more difficulties were thrown in his way on his returt. from Poland, especially in Hesse-Casse ostensibly on account of his coming from a country infested with cholera, but in reality on account of his political principles. After his return to Paris, he was near being sent by Périer to Avignon with the Poles. Towards the end of 1831, he left Paris and went to Italy. He possesses a plaster cast of Napoleon, made from a mask taken immediately after his death. APHIDES, or VINE-FRETTERS. Ants.) (See | APLOME. (See Garnet.) ARBALIST. (See Cross-Bow.) ARBORIZATIONS. (See Dendrites.) ARCOPOLIS. (See Little Rock.) ARCTIC SEAS. (See North Polar Expeditions.) ARGENTINE REPUBLIC. An account of this state will be found under the head of Plata, United Provinces of the. ARQUEBUSS. (See Harquebuss.) ARROW-HEAD CHARACTER. (See Persepolis, and Writing.) ARTIGAS. We have to add to the arcount given of this general, that he was retained prisoner by doctor Francia, who treated him, at the same time, with great kindness, and provided for his comforteble support. He died in 1826. ARUNDEL, EARL OF. (See Howard, Thomas.) ARZERUM. (See Erzerum.) ASTHMA (asthma, Latin; from to breathe with difficulty); difficulty of respiration, returning at intervals, with a sense of stricture across the breast and in the lungs, a wheezing, hard cough, at first, but more free towards the close of each paroxysm, with a discharge to time throughout the day; and, the disof mucus, followed by a remission.- ease going off at last, the patient enjoys Asthma rarely appears before the age of pu- his usual rest by night, without further berty, and seems to attack men more fre- disturbance. The exciting causes are &quently than women, particularly those various :-accumulation of blood or viscid of a full habit, in whom it never fails, by mucus in the lungs, noxious vapors, a frequent repetition, to occasion some de- cold and foggy atmosphere, or a close, gree of emaciation. In some instances, hot air, the repulsion of eruptions, or othit arises from a hereditary predisposition; er metastatic diseases, flatulence, accuand in many others, it seems to depend mulated feces, violent passions, organic upon a particular constitution of the diseases in the thoracic viscera, &c. lungs. Dyspepsia always prevails, and Sometimes the fits return at pretty regular appears to be a very prominent feature in periods; and it is generally difficult to obthe predisposition. Its attacks are most viate future attacks, when it has once ocfrequent during the heats of summer, in curred: but it often continues to recur the dog-days, and in general commence for many years, and seldom proves fatal, about midnight. On the evening preced- except as inducing bydrothorax, phthisis, ing an attack of asthma, the spirits are &c. The treatment must vary according often much affected, and the person ex- to the form of the disease. By far the periences a sense of fulness about the most important part of the treatment constomach, with lassitude, drowsiness, and sists in obviating or removing the several a pain in the head. On the approach of exciting causes, whether operating on the the succeeding evening, he perceives a lungs immediately, or through the medisense of tightness and stricture across the um of the prima viæ, &c. Individual breast, and a sense of straitness in the lungs, experience can alone ascertain what state impeding respiration. The difficulty of of the atmosphere, as to temperature, drybreathing continuing to increase for some ness, purity, &c., is most beneficial to length of time, both inspiration and expi- asthmatics, though a good deal depends ration are performed slowly, and with a on habit in this respect; but a due reguwheezing noise; the speech becomes dif- lation of this, as well as of the diet, and ficult and uneasy; a propensity to cough- other parts of regimen, will usually afford ing succeeds, and the patient can no longer more permanent relief than any mediremain in a horizontal position, being as cines we can employ. it were threatened with immediate suffocation. These symptoms usually continue till towards the approach of morning, and then a remission commonly takes place; the breathing becomes less laborious and more full, and the person speaks and coughs with greater ease. the cough is attended with an expectoration of mucus, he experiences much relief, and soon falls asleep. When he awakes in the morning, he still feels some degree of tightness across his breast, although his breathing is probably more free and easy, and the least motion renders this more difficult and uneasy; neither can he continue in bed, unless his head and shoulders are raised to a considerable height. Towards evening, he again becomes drowsy, is much troubled with flatulency in the stomach, and perceives a return of the difficulty of breathing, which continues to increase gradually, till it becomes as violent as on the night before. After some nights passed in this way, the fits at length moderate, and suffer more considerable remissions, particularly when they are attended by a copious expectoration in the mornings; and this continues from time If ASTROMETER. (See Heliometer.) ATOMIC THEORY, in chemistry. Two opposite opinions have long existed concerning the ultimate elements of matter. It is supposed, according to one party, that every particle of matter, however small, may be divided into smaller portions, provided our instruments and organs were adapted to the operation. Their opponents contend, on the other hand, that matter is composed of certain atoms, which are of such a nature as not to admit of further division. These opposite opinions have, from time to time, been keenly contested, and with variable success, according to the acuteness or ingenuity of their respective champions. But it was at last perceived that no positive data existed capable of deciding the question; and its interest, therefore, gradually declined. The progress of modern chemistry has revived the general attention to this controversy, by affording a far stronger argument in favor of the atomic constitution of bodies than was ever advanced before, and which seems almost irresistible. We have only, in fact, to assume, with Mr. Dalton, that all bodies are composed of ultimate atoms, the weight of which is different in different kinds of matter, and we explain at once various laws of chemical union. According to this view, every compound is formed by a combination of the atoms of its constituents. An atom of A may combine with 1, 2, 3, or more atoms of B-an arrangement on which depends the law of multiples. If water, for example, is composed of an atom of hydrogen and an atom of oxygen, it follows that every compound of hydrogen with an additional quantity of oxygen, must contain 2, 3, or more atoms of oxygen; some multiple in a word by a whole number of the quantity of oxygen contained in water. It is equally clear, from this view of the composition of water, that the weight of an atom of oxygen is eight times heavier than an atom of hydrogen. The relative weight of the atoms of other substances may be determined in a similar manner. Thus an atom of carbon is 6 times, an atom of sulphur 16 times, and an atom of chlorine 36 times, heavier than an atom of hydrogen; and this explains why they unite with one another in the proportions expressed by those numbers. What are called the proportional numbers are, in fact, nothing else but the relative weights of atoms. No one can suppose that the laws of chemical union are the effect of chance there must be some cause for them in the nature of the ultimate particles of matter. This cause, as we have just seen, is completely supplied by the supposed atomic constitution of bodies, which accounts for the phenomena in the most beautiful and consistent manner. So perfect, indeed, is the explanation, that the existence of these laws might have been predicted by the aid of the atomic hypothesis long before they were actually discovered by analysis. But these are not the only arguments which we at present possess in favor of the existence of ultimate indivisible particles of matter. Doctor Wollaston, in his paper on the Finite Extent of the Atmosphere (Philosophical Transactions, 1822), has defended this side of the question on a new and independent principle; and the proof he has given of the atomic constitution of bodies appears decisive. Some chemists, even without expressly adopting the atomic theory itself, have followed Mr. Dalton in the use of the terms atom and atomic weight, in preference to proportion, combining proportion, equivalent, and others of a like kind. All these appellations, however, have the same signification; and, in using the word atom, instead of the : others, it should be held in mind that it merely denotes the proportions in which bodies unite; that it is the expression of a fact which will remain the same, wheth er the atomic hypothesis which suggested the employment of the term be true or false. There is one circumstance which, at the first view, seems hostile to the supposed atomic constitution of matter. According to the law of multiples (see Chemical Equivalents), oxygen. in the three oxides of lead is in the ratio of 1: 13:2; so that, if we regard the protoxide as composed of one combining proportion of lead to one proportion of oxygen, the second will contain one proportion and a half, or, according to the atomic theory, one atom and a half of oxygen. Now, though the half of a combining proportion may be admitted, the existence of half an indivisible particle of matter is inconceivable; and this circumstance would be fatal to the atomic theory, were there not some satisfactory mode of accounting for it. Several explanations might be brought forward. One of them, which has found its advocates, rests on the supposition that what is called the protoxide, is, in reality, composed of one atom of lead to two atoms of oxygen; and that the real protoxide has not yet been discovered. Another mode of accounting for the anomaly is, by regarding the present deutoxide composed of the protoxide and peroxide combined with each other. A third method is, by doubling both elements of the anomalous compound, by which the exact ratio is preserved, and the idea of the fraction of an atom is avoided. Thus the protoxide and peroxide of iron are couposed, the first, of one proportion, or 2 of metal + 8 of oxygen, and the second, of 28 of metal + an atom and a half, or 12 of oxygen; or, what amounts to the same thing, of 56, or two atoms of iron, to 24, or three atoms of oxygen. These observations prove, that the occurrence of half proportions is not inconsistent with the atomic constitution of bodies: they show that the difficulty is explicabie, and probably will, in the progress of discovery, be entirely removed. In the mean time, however, it would be inconvenient to allow any speculative notions on the subject to interfere with actual practice; and, therefore, it is best at once to admit the occurrence of half proportions; and, if any one prefer the term atom to equivalent or proportion, he must submit to the somewhat jarring expression of half an atom. Mr. Dalton sup poses that the atoms of bodies are spherical, and has invented certain symbols to represent the mode in which he conceives they may combine together. (See his New System of Chemical Philosophy.) There are several questions relative to the nature of atoms, most of which will, perhaps, never be decided. Of this nature are the questions which relate to the actual form, size and weight of atoms, and to the circumstances in which they mutually differ. All that we know with any certainty is, that their weights do differ, and by exact analysis the ratios between them may be determined. The numbers which indicate the combining proportions of bodies, are, in fact, the relative weights of their atoms. AUK. (See Pinguin.) AUSTEN, Jane, a gifted novelist, was born Dec. 16, 1775, at Steventon, in the county of Hants, of which parish her father was rector. Upon his death, his widow and two daughters retired to Southampton, and ultimately, in 1807, to Chawton. During her residence in the last-mentioned place, Miss Austen composed the novels, which, for ease, nature, and a complete knowledge of the features which distinguish the domestic life of the English country gentry, are very highly esteemed. The principal of these productions are Sense and Sensibility; Pride and Prejudice; Mansfield Park; and Emma. Two more were published after her death, entitled Northanger Abbey, and Persuasion, which were, however, her most early attempts. The object of Miss Austen, in all her works, was to advocate the superiority of sound principle, unsophisticated manners, and undesigning rectitude, to showy and artificial pretensions. Her discrimination was acute, her humor easy and spontaneous, and her power of creating an interest in her characters by slight and reiterated touches, extraordinary. This amiable and accomplished lady, whose personal and mental attractions were of a high order, died of a decline, on the 18th of July, 1817, in her forty-second year. AVIARY. The aviary was common to the country-houses of the Romans, but used principally, as it would appear from Pliny, for birds destined to be eaten. Singing-birds, however, were kept by the Persians, Greeks, and also the Romans, in wicker-cages; and these utensils, no doubt, gave rise to the large and fixed cage called an aviary; but in what country, and in what age, appears uncertain. They are highly prized in China. In the altercations which took place during lord Amherst's embassy, it was stated, on the part of the emperor, that sir George Staunton had built himself a house and an aviary. That they were in use in England in Evelyn's time, is evident from a memorandum entered in his diary, that the marquis of Argyle took the parrots in his aviary at Sayes' court for owls.-The canary, or singing-bird aviary, used not unfrequently to be formed in the opaqueroofed green-house or conservatory, by enclosing one or both ends with a partition of wire, and furnishing them with dead or living trees, or spray and branches suspended from the roof for the birds to perch on. Such are chiefly used for the canary, bullfinch, linnet, &c.-The parrot aviary is generally a building formed on purpose, with a glass roof, front and ends; with shades and curtains to protect it from the sun and frost, and a flue for winter heating. In these, artificial or dead trees, with glazed foliage, are fixed in the floor, and sometimes cages hung on them; and at other times the birds allowed to fly loose.-The verdant aviary is that in which, in addition to houses for the different sorts of birds, a net or wire curtain is thrown over the tops of trees, and supported by light posts or hollow rods, so as to enclose a few poles or even acres of ground, and water in various forms. In this the birds in fine weather sing on the trees, the aquatic birds sail on the water, or the gold-pheasants stroll over the lawn; and in severe seasons they betake themselves to their respective houses or cages. Such an enclosed space will of course contain evergreen as well as deciduous trees, rocks, reeds, aquatics, long grass for larks and partridges, spruce firs for pheasants, furze-bushes for linnets, &c. An aviary, somewhat in this way, was formed by Catharine of Russia, in the Hermitage palace. These are the only sorts admissible in elegant gardens; since nothing, to one who is not an enthusiast in this branch of natural history, can be more disagreeable than an apartment filled with the dirt and discordant music of innumerable birds; such, for example, as the large aviary at Kew. Birds from the hot climates are sometimes kept in hot-houses among their native plants, as in the large conservatories at Vienna. In this case, the doors and openings for giving air must be covered with wire cloth, and the number must not be great, otherwise they will too much disfigure the plants with their excrement.-Gallinaceous aviary. At Chiswick, portable net ted enclosures, from ten to twenty feet square, are distributed over a part of the lawn, and display a curious collection of domestic fowls. In each enclosure is a small wooden box or house for sheltering the animals during night, or in severe weather, and for breeding. Each cage or enclosure is contrived to contain one or more trees or shrubs; and water and food are supplied in small basins and appropriate vessels. Curious varieties of aquatic fowls might be placed on floating aviaries on a lake or pond. AXLE. (See Mechanics.) B. BABYROUSSA. (See Hog.) BALBI, Adrian, born in Venice, was appointed professor of natural philosophy and geography in his native city, and, about the year 1820, went to Portugal. Here he became acquainted with the most influential politicians and literary men, and collected, in the archives of the government and elsewhere, materials for his Essai statistique sur le Royaume de Portugal et d'Algarve (Paris, 1822, 2 vols.). This excellent work contains, among otlier things, a chapter on Portugal in the time of the Romans. The political part of the work is the least complete; but Balbi expressly says that there are particular causes for this. In 1826 appeared at Paris his Atlas Ethnographique, in one folio volume, and an octavo volume, containing illustrations. This useful work contains a great deal of new information obtained from men like A. von Humboldt, Freycinet, Remusat, William von Humboldt, Champollion, Hase, Jomard, Klaproth, Malte-Brun, Ritter and others. The chapter on the different inodes of writing among various nations is peculiar ly interesting. Balbi has also published, in Paris, statistical tables on Russia, France, the Netherlands, &c., which he intends to use for a great work. He has written several excellent articles in the Revue Encyclopédique, the Revue des deur Mondes, and the Revue Britannique. He is now publishing a geographical manual, and, after the publication is completed, will return to Italy, where a professorship of geography awaits him. BALIZE. (See Honduras.) BARANTE, Prosper Bruguiere de, a French politician and man of letters, was born at Riom, in Auvergne, in 1783, and is descended from an old noble family. Under Napoleon, he was appointed auditor of the council of state. He was then sent as sub-prefect to Bressuire; some time after, was made prefect of the Vender, and, subsequently, of the still more important department of the Loire. Has brother was sub-prefect of Luxemburg, and his father had been prefect of the department of Leman. In 1809, Barante married a Miss Houdelot, grandeluid of Mad. d'Houdelot, celebrated in the Coufessions of Rousseau. When Louis XVIII returned, after the hundred days, Barante came into special favor. He received the lucrative post of superintendent of the indirect taxes, having been previously made counsellor of state. The depart ment of the Puy-de-Dome elected him deputy; and he supported the ministers of Louis. He retained his post until the downfall of Decazes (q. v.), but was subsequently made peer. He now voted with the moderate party, and opposed several measures under Charles X, wra were contrary to the spirit of the charter. His speeches contained many wise observations As soon as the house of Or leans was raised to the throne, Baranə was sent as minister to the court of Turu, where he was still in the spring of 1822 He published, in 1809, a work on Frenc.. literature in the eighteenth century, azsi contributed to the Biographie Univerma some important articles, as Froissart, al Bossuet. While prefect in the Vetre, he became acquainted with the fans us madame de la Rochejaquelein. He offer ed her his assistance in the prepATALO of the history of the war in the Venore. and to him is ascribed the Memoires Madame de la Rochejaquelcin, wi went through several editions. He a contributed to Ladvocat's Theatre Etrang'i, and translated soine of the productions vi Schiller. He seems, likewise, to Lascontributed to Broglie and Guizot's Roza Francaise. In 1829, he published an es say on the government of the communes, when this question was agitated under Martignac. This essay shows a very perfect knowledge of foreign laws and stitutions. From 1824 to 1826 appears ten octavo volumes of his History Ducs de Bourgogne. It comprises a pe riod of little more than a hundred years |