Echinometra. (Gray.) Scutella. (Mellita, Klein; Echinodiscus, Leske.) Body irregularly circular, wider behind, extremely deBody thick, solid, transversely oval, a little depressed, pressed, borders nearly sharp-edged, sub-convex above, a convex, with the summit (which is median) flat above and little concave below, composed of large polygonal scales arched below, covered with mamillated tubercles of two and covered with very small, uniform, and scattered spines. sorts and bearing diversiform, but always strong and large Ambulacra five, more or less petaliform, the two rows of spines. Ambulacra five, enlarging themselves below. Bucpores of each branch united by transverse furrows, which cal opening of the shell large, transverse, with very powermakes them appear striated. Mouth median, round, fur-ful auricles on its internal circumference. Five sharp teeth nished with teeth, and towards which converge five vasculi- at the mouth, with a complicated apparatus, as in Echinus. form furrows more or less ramified and sometimes bifid Vent medio-superal or opposed to the mouth. from the base. Vent always inferior and at some distance pores to the number of five. Example, Echinometra from the border. Genital pores four. LIVING SPECIES. a. Species whose disk alone is perforated. Example, Scutella hexapora. B. atrata. Genital Localities.-The seas of warm climates. Unknown in those of England and France. No fossil species known. Echinus. Species whose disk and borders are perforated. Ex-rows, alternately unequal, of polygonal plates bristled with ample, Scutella tetrapora. Y Species whose border only is notched. Example, number of five and complete. Mouth central, armed with Scutella aurita. 8. Species whose disk and border are entire. Example, Scutella integra. 2. Body in general very regularly circular or sub-polygonal, sometimes slightly transverse, composed of twenty radiated diversiform spines of two kinds, and supported on imperforate mamillated tubercles. Ambulacra constantly to the five pointed teeth, supported upon a very complicated internal apparatus. Vent median, superior, or exactly opposite to the mouth. Genital pores to the number of five. Food. The food is generally believed to consist of mollusks and crustaceans. Tiedemann found in E. Saxatilis small univalve and bivalve shells entire among the excreBosc is said Species whose disk is perforated and their border mul- ments, as well as fragments of larger ones. tidigitated. Example, Scutella octodactyla. %. to have witnessed an Echinus in the act of seizing and devouring a small crustacean. Dr. Sharpey usually found in the intestine of E. esculentus small morsels of sea-weed, the excrements, which are in the form of small round pellets about the size of peppercorns, consist chiefly of sandy matter with fragments of shells. But he adds that it would be difficult to say whether these are the remains of digested mollusca or merely a portion of the usual testaceous debris so abundant in sand and mud. Species whose disk is imperforate and the boraer mul-for the most part encrusted with flustra; and he says that tiradiated. (Demi-soleils.) Example, Scutella dentata. Localities. The living species whose habitat is known are foreign, and the South Seas appear to be their principal locality. Nevertheless, as De Blainville observes, we ought to remember that Defrance, in the description of a fossil species, Scutella Hispana, says, that it bears great resemblance to a species that lives in the English Channel and which is found on the coasts in the department of Calvados. De Blainville adds, that he has not seen this species, and that it is the first time we find it stated that a Scutella exists in our seas. None of the English, Italian, or French authors whom he consulted mention it. FOSSIL SPECIES. Tolerably numerous and occurring generally in the calcaire grossier of Paris, Grignon, and the environs of Nice. None as yet recorded in any other beds than those posterior to the chalk Sub-family IV Mouth quite central. Summit median. Body regularly oval or circular, covered with tubercles and mamillæ, and consequently with spines of two sorts. Vent variable, ordinarily medico-dorsal. Genera. Galerites (Fossil only) Conulus, Klein; Echinoconus, De Blainy. Body nearly regularly circular or polygonal, entirely flat below, convex and often conical with the summit median above, formed of very dissimilar plates and covered with tubercles of two kinds. Ambulacra complete, narrow, to the number of five or four, dorso-buccal. Mouth central and probably armed. Vent infero-marginal. Genital pores to the number of five. α. Species with four ambulacra and consequently with six series of plates. Example, Galerites quadrifasciatus. α. Arbacia, Gray; Echinocidaris, Desmoulin. Species perfectly regular, ordinarily depressed; area very unequal; ambulacraires very narrow, bordered by ambulacra nearly straight, and composed to the right and left of a double series of approximated pores; auricles divided and spatulate. Example, Echinus pustulosus. B. Regular species, more or less convex, but, for the rest, diversiform; areæ sub-equal, bordered by a double series of pores, forming at the exterior, denticulations more or less marked and each with three pairs of holes. De Blainville subdivides this section into three, with still further subdivisions depending on the non-fissured or more or less fissured angles of the buccal opening of the shell, and other variations. He states that he has been able to study a great number of living species, and though many have been only known to him by means of the shell, he has been able, he says, to find constant specific characters: 1st, in the proportion of the ambulacral and anambulacral area; 2nd, in the number of lines of double pores which limit the ambulacra; 3rd, in the number of those double pores which form the festoons of these lines; 4th, in the form of the auricles, serving for the insertion of the muscles of the dental apparatus; 5th, in the disposition of the border of the buccal orifice. He states as a result, that though he has indicated nearly double the number of species pointed out by Lamarck, they are much more easily recognized. Localities, Habits, &c.-The form is widely diffused, and there are species in most European seas. The Mediterra- | in the peculiar character of the ambulacra, he has united nean produces some very fine ones. They live free at the them to the former under the same name. Mr. Gray rebottom of the sea at considerable depths, or on the rocks marked, as throwing doubt on the bilaterality of the Echiof the coast in the midst of fuci. They lay an immense nidae attempted to be established by M. Agassiz, that the quantity of eggs. spongy ovarial plates which that gentleman regarded as the mark of the hinder part of the Echinide, is always placed species. See also Mr. Gray's paper on the genera of these on one side or the other of the longer axis of the oblong article Echinodermata' in the Cyclopædia of Anatomy animals in the Annals of Philosophy;' and Dr. Sharpey's and Physiology.' FOSSIL ECHINI. Desmarest distinguishes thirteen species from the beds anterior and posterior to the chalk. Risso gives one new from the environs of Nice, and Goldfuss nine from Ger many. Cidaris. Body circular, regular, more or less elevated or depressed, composed of polygonal plates, covered with mamillated tubercles constantly perforated at the summit, and supporting spines of two kinds: one very long and sharp, the others short and nearly squamous. Ambulacra complete, to the number of five. Mouth below, central, furnished with five pointed teeth. Vent superior and central. Genital pores to the number of five. a. Subspheroidal species, more elevated than wide, with very narrow ambulacral area; the lines of double pores sinuous. (The Turbans.) Example, Cidaris imperialis. B. Orbicular species, depressed; ambulacral area less narrow, bordered by straight ambulacra; spines ordinarily fistulous. (Diadema, Gray.) Example, Cidaris Diadema. 7. Orbicular species, very depressed; interambulacral area equalling the half of the others, and bordered by straight and very large ambulacra. (Astropyga, Gray.) Example, Cidaris radiata. Localities.-Seas of the southern hemisphere. Two species already known in the seas of Britain and France, one on the coasts of Scotland, rare; the other very common in the Mediterranean. FOSSIL SPECIES. Cidaris occurs in a fossil state in the chalk and the an terior beds. Defrance mentions three, but hardly charac terizes them. Risso adds two new ones; Fleming four; and Goldfuss has figured and characterized nineteen. Mr. Gray (Proceedings of the Zoological Society, 1835) divides the genus Echinus, as restricted by Lamarck and modern authors, into what he considers four natural genera, adapted to facilitate the distinction of the species of this extensive group. He regards this distinction as of the more importance, inasmuch as some of the characters which had been used for this purpose, such as the number of the tesserce and of the pores in the ambulacra, have been found to be inconstant; the number of these increasing, as they are now known to do, with the age of the specimens. The following is Mr. Gray's subdivision:-Genus 1. Arbacia. This corresponds with section A of M. de Blainville. Example, Arbacia pustulosa (Echinus pustulosus, Lam.) Genus 2. Salenia, only known in a fossil state, and hitherto confounded with Cidaris; but its tubercles are not pierced. Example, Salenia scutiger (Cidaris scutiger, Munst.) Genus 3. Echinus containing sections B, C, E, and G of De Blainville. Mr. Gray divides it into two sections:1. The species with narrower ambulacra and with the pores moderate and approximated, which is subdivided into those with a subintegral mouth (type, Echinus esculentus) and those with the mouth deeply incised. (Example, Echinus excavatus, Lam.) 2. The species with wide ambulacra; the pores separated by small tubercles; the mouth five-incised. Example, Echinus ventricosus, Lam. Genus 4. Echinometra, containing sections B**, D, and F of De Blainville, as well as the Echinometra of that author. In this genus Mr. Gray observes the ambulacral plates may be considered as being composed of five or more doublypierced pieces, which form an arched line round the outer edge of the tessera, with a single pair of pores at its lower inner angle. Mr. Gray stated that he had formerly separated from the Echini some of the species of this genus, which are peculiar for their oblong form, and that the genus so proposed by him had been adopted by M. de Blainville; but a much more extended examination had convinced Mr. Gray that individuals of the same species vary from roundish to oblong; and therefore, having observed many round species agreeing with the oblong ones ECHINOBRI'SSUS. [ECHINIDE, p. 259.] ECHINOCACTUS, a genus of Cactaceous plants, with the stem of an ovate or spheroidal form, the sides being divided into many ribs, upon whose projecting angles are stationed at short intervals little spiny stars, which are the rudiments of leaves, and from whose centre the flowers appear. The latter consist of numerous sepals collected into à tube, an equally large number of petals, numerous stamens, and a filiform style divided into many lobes at the point. The species are very remarkable for the singular forms of their stems, and for the curious manner in which their spines are arranged. They are often moreover conspicuous for the beauty of their large flowers. The genus is extremely near Cereus, from which, according to De Candolle, it only differs in having the sepals and petals distinct from each other, not united into a tube. But as Cereus triangularis has its sepals distinct, and all the Echinocacti have more or less of a tube, we consider it better to limit the latter to such species as have a depressed or spheroidal form. With such a limitation the Echinocactus Eyriesü, one of the most beautiful of plants, will really belong to the genus Echinocactus, of which it has all the habit; otherwise it would be a Cereus, to which its stems bear but little resemblance. Most of the species are natives of Mexico and the West Indies. A few are found in Brazil. Echinocactus Eyriesü, ECHINODE'RMATA. Lamarck made his Radiaires Echinodermes consist of three sections. 1st, the Stellirideans (star-fishes), including Comatula, Euryale, Ophiura, and Asterias; 2nd, the Echinidae; and 3rd, the Fistulida, comprehending Actinia, Holothuria, Fistularia, Priapulus, and Sipunculus. Cuvier's Echinodermes form his first class of zoophytes, and this class is divided into two orders, viz., 1st, the Pedicillated Echinoderms, containing the great genus Asterias and its subgenera the Encrinites, the Echinidae, and Holothuria; and 2nd, the Footless Echinoderms, consisting of Molpadia, Minyas, Priapulus, the Lithoderms, Sipunculus, Bonellia, and Thalassema, with its subgenera Echiurus and Sternaspis. De Blainville's Echinodermata are placed as his first ridea, embracing the Encrinites as well as the Free Starfishes, &c. The Echinodermata belong to the Cycloneurose subkingdom. class of Actinozoa, and are divided into three orders: 1st, the space of a conical frustum aACc, the vertex of the cone Holothuridea; 2nd, Echinidea [ECHINIDE]; 3rd, Stelle-R being situated symmetrically with O at the opposite side of AC. In order that a person may hear the echo of his own sounds, it is therefore necessary that his situation may be at a point O' in a perpendicular to AC; and that a second person may hear the echo of the voice of another at O, he must be situated in the frustum aACc, so that the angles of incidence and reflection of the sound which reaches his ear may be equal; in both cases the distance from AC must be sufficiently great to distinguish between the original and the reflected sound. ECHINODISCUS. [ECHINIDE, p. 260.] ECHITES, a genus of twining Apocynaceous plants inhabiting tropical countries. They have handsome yellow or white corollas, and are moreover remarkable for the singular fruit, which consists of two divaricating woody podlike follicles containing a large number of silky seeds. They are dangerous lactescent plants of no known use. E'CHIUM, an irregular-flowered genus of Boraginaceous plants, with handsome campanulate corollas. Echium vulgare is the most striking of our wild herbaceous plants; many species found at the Cape of Good Hope are shrubs. ECHO. (x, xos, sound). When sonorous undulations are propagated from any origin through the elastic medium of the air, the spherical wave-like surface then generated conveys the sound through the circumjacent space, and moves from its origin and centre with a velocity of about 1125 feet in a second, at the ordinary atmospheric pressure and temperature; for the velocity of undulations propagated through elastic media depends only on their indices of elasticity and not on their intensity. [ACOUSTICS.] Suppose the point O to be the origin of a sound which in its progress encounters a plane obstacle NM; if this plane be sufficiently extended, a point M may be easily found which the sound will have just reached at the end of a given time. The waves which have previously reached the nearer points A,B,C, being precluded from advancing, are there reflected, that is, new spherical undulations a'ab, b'bc, c'cd are generated from A,B,C as centres, and their radii at the moment we have spoken of are respectively Ab-OM-OA, Bc=OM-OB, Cd=OM—Oc, and it is easily seen that all these spherical surfaces originating from A up to M and existing simultaneously, may be exactly enveloped by a single por tion of a spherical surface of which the centre is placed in a position R corresponding to O in respect to its distance from NM, but at the opposite side of the obstacle; this spherical surface, of which the radius is RM, is the true returning wave at that moment, and being impressed on the auditory organs, so as to be distinguished from the original sound, is called the echo. C When a sound originates at a point O, and is reflected by a plane obstacle AC, the reflected pulsation of the air occupies Hence it follows, that wherever a person is situated, the echo of a single sound necessarily follows and cannot precede the original sound, for the two sides OA, Aa are greater than the third Oa through which the direct sound is propagated, and the velocities are in both cases alike. However, the echo of a continued sound or note may be heard in the inverse order of time to that in which it was generated, provided the origin of the sound moves more rapidly towards the hearer than the rate at which sound travels. Thus a flash of lightning moving towards a person will produce a roll of thunder which, echoed by clouds, will be heard as it were backwards; but if the direction of the flash be such that the points of its current are nearly equidistant from the auditor, an instantaneous and intensely loud clap will be substituted for a continued roll. The murmuring sound produced by the discharge of great guns is the succession of echoes from the particles of vapour floating in the atmosphere, and when the discharge is effected under a dense cloud, the echoes are stronger and better reflected, and a noise resembling a thunder-roll may then be heard. The whizzing of a bullet is attributed to its impinging in a state of rapid rotation on particles of vapour. The time intervening between the primitive sound and its echo has sometimes been employed in determining the distance from the observer to the reflecting object, allowing 571 feet for each intermediate second of time; but like all methods dependent more on individual judgment than mechanical measurement, this process must be liable to considerable irregularities. When several objects reflect sound, the number of echoes is greatly multiplied, not only from the primary echoes of each, but also from secondary and tertiary echoes by second and third reflections of returning waves against the reverberatory obstacles: each re-echo consists of only portions or frusta of the preceding; their intensities therefore diminish, and they gradually die away upon the ear, in the same manner that the images become obscure and by degrees imperceptible in consequence of the diminution of light when we look between two opposite and parallel plane mirrors. The first echo heard in such circumstances is by no means necessarily the loudest. Taking any ellipse of which one focus is the origin of the sound and the other the place of the auditor, it is a well-known property of this curve that right lines drawn from the foci to any point in it make equal angles with the tangent at that point. Con ceive now this ellipse to rotate round the line joining the foci so as to form a prolate spheroid, then sound emanating from one focus and reflected by a portion of the surface will be directed after reflection to the other, and its intensity will depend on the solid angle subtended at the focus by the reflecting body. Each echoing body may be conceived as a portion of such a spheroidical surface, taking a great axis major to comprehend the more distant bodies; and since the sum of the solid angles subtended by the more distant reflectors may be greater than those given by the nearer, the echo produced by them, though not reaching the ear as soon as that of the nearer, may, under such circumstances, be louder, bearing in mind in our estimate that this intensity has a source of diminution in the increase of distance. This case frequently occurs in places encompassed by chains of mountains, as the Killarney and Welsh lakes, &c. When the succession of echoes from several bodies is sufficiently rapid, a continued sound or note may be produced, though the original sound was merely momentary; and when not sufficiently rapid for this purpose, a clamorous noise is produced, and hence Echo with her thousand tongues and babbling propensities has furnished matter for poetic imagination from Ovid to Shakspeare. As a single ha may be converted into an imitation of a stunning laugh, the romantic and echoing regions inhabited by the Scandinavian races materially assisted their untutored_ima ginings in attributing this appalling music to the aerial revelries of invisible hags or witches. But when, as in the case of the electric fluid, the original cause of sound may be said to exist simultaneously through an extensive tract of an excited atmosphere, a sound perfectly continuous and majestic is produced in the thunderroll, which may frequently be heard again echoed by neighbouring clouds, or awfully prolonged by repeated reflections from an amphitheatre of mountains. A similar effect of rapidly repeated echoes may be perceived in the prolonged tread and ringing sounds which we hear when walking in stillness through long galleries, cloisters, and other narrow passages with parallel sides, particularly when the air is confined; but hangings and carpetings, yielding to the impulse of the sonorous waves, or stifling them by a multitude of interior reflections, together with open windows or much furniture, diminish these effects to a great extent. The distribution of sound in public edifices, so that the echoes may be most advantageously brought to strengthen the original sound, is a subject practically deserving of much attention. For some sensible observations on the errors of architects in this respect, we must refer to Sir J. Herschel's treatise on Sound. Certainly the unlucky error of placing the confessional in the cathedral of Girgenti in a focus conjugate to another and unenclosed part of the church, by which Echo was instrumental in informing a husband of the infidelity of his spouse, and the parabolic reflector of a late ingenious clergyman at Cambridge, which had the effect of completely stunning him, however impartially his voice was distributed to his congregation, are not inconveniences of such common occurrence as those contrivances by which a part of an audience in a church or theatre possesses a monopoly, while the remainder witness the ceremony or performance in dumb show. A ludicrous anecdote, mentioned by Lord Bacon, of a Frenchman calling out Satan, and being answered Va-t'en, led him to assert that the letter S was not echoed, and this assertion has been copied by several cyclopedists. The fact is, that S being in a great measure a breathing, the distance necessary for the production of a distinct echo is too great to render it audible, owing to its small intensity; but when its echo is taken at a small distance, the effect is to increase the sound, and this very disagreeable prolongation is very perceptible in churches whenever persons in repeating the service make use of this letter. The whispering gallery of St. Paul's is another instance of this error, for a low whisper uttered at one end is conveyed by successive reflections along its curved roof, and being again concentrated at the other end, may be distinctly heard. When the reflecting surfaces, instead of plane, are curved, as in caverns, grottos, rocks, or ruined buildings, the reflected sound will be most intense at the foci, or the points which would be most enlightened by reflection if a luminous body were substituted in the place of the original source of sound. Whatever may be the figure of the echoing surface, the total path traversed by a wave in a given time before and after reflection taken together is constant (and in different times is proportional to the time); therefore a small portion of a plane section of the echoing surface is common also to an ellipse having one focus at the origin of sound, the other in the returning wave, and the axis major equal to the space traversed by sound in a given time. Hence, first, the plane sections of the returning wave are the loci of the second foci of a series of ellipses, having a common focus and equal axes major, and all touching the section of the echoing surface; and, secondly, the figure of an obstacle necessary to produce a given wave will be found by taking the curve which touches a series of ellipses having their second foci in this wave surface and their first focus and axes major as before: this, strictly speaking, should however be confined to surfaces of revolution. E'CIJA, a town of Andalusia, in the intendencia or province of Sevilla, situated on the river Genil, in a fine plain, on the high road from Sevilla to Cordova, about 55 miles north-east of the former city. Its antient name was Astigis; the Romans afterwards gave it the name of Colonia Augusta Firma. The name of Ecija was given to it by the Moors (Miñano). Ecija has a population of 34,000 inhabitants, many churches and convents, several hospitals, and other public buildings, and a very fine promenade along the banks of the Genil, adorned with fountains and statues. It is the residence of a corregidor and an alcalde mayor. The territory is rich in corn and olives; there are also some manufactories of woollens and linens. Ecija is the birthplace of Luis Velez de Guevara, a Spanish dramatist of the seventeenth century. There are several Roman inscriptions and a few other remains of antiquity. ECKHEL, JOSEPH HILARY, an eminent antiquary and numismatist, was born at Entzersfeld, in Austria, January 13, 1737. His father, who was in the service of Count Sinzendorf, sent him at a very early age to the Jesuits' College at Vienna, where, in 1751, he was enrolled in their society. He studied philosophy, mathematics, divinity, and the learned languages; but devoted himself chiefly to antiquities and medals. His skill in the latter induced the superiors of the college, a few years afterwards, to give him the place of keeper of their cabinet of medals and coins. In 1772 he went to Italy, where the grand duke of Tuscany, Leopold II., engaged him to arrange his collection; and on his return to Vienna, in 1774, he was appointed director of the Imperial Cabinet of Medals, and professor of antiquities. In 1775 he published his first work upon his favourite study, entitled Numi veteres Anecdoti ex Museis Cæsareo Vindobonensi, Florentino Magni Ducis Etruriæ, Granelliano nunc Cæsareo, Vitzaino, Festeticsiano, Savorgnano Veneto, aliisque,' 4to Vienna. This was followed in 1776 by Catalogus Musei Cæsarei Vindobonensis Numorum Veterum, distributus in partes ii. quarum prior Monetam Urbium, Populorum, Regum, altera Romanorum complectitur,' 2 tom. folio, accompanied by eight plates of inedited coins. In 1786 he published his 'Sylloge 1ma. numorum anecdotorum Thesauri Cæsarei,' 4to.; and his Descriptio Numorum Antiochiæ Syriæ, sive Specimen Artis critica Numariæ,' 4to., likewise printed at Vienna, the same year: and in 1787 produced a small elementary work on coins for the use of schools, in his native language, entitled 'Kurzgefasste Anfangsgründe zur alten Numismatik,' 8vo., Vien. This work has more recently been improved and published in France, under the title of Traité Elémentaire de Numismatique Grecque et Romaine, composé d'après celui d'Eckhel,' par Gerard Jacob, 2 tom. 8vo., Par. 1825. In 1788 Eckhel published a folio volume upon the gems of the Imperial Collection, 'Choix de Pierres gravées du Cabinet Imperial des Antiques, représentées en xl. Planches ;' and in 1792 the first volume of his Doctrina Numorum Veterum,' Vienna, 4to.; the eighth and last volume of which was published in 1798. A supplement to it, with his portrait prefixed, has since_appeared, 'Addenda ad Eckhelii Doctrinam Numorum Veterum ex ejusdem Autographo postumo,' 4to., Vindob., 1826. This work, which embraces the science of numismatics in general, has placed Eckhel at the head of all the writers upon antient coins. He died, May 16th, 1798, at the house of his friend the Baron de Locella. In his younger years Eckhel published three or four small pieces unconnected with numismatics: namely, two Latin odes on the nuptials of Joseph II., in 1765; another in German, in 1768, on the departure of Maria Carolina, archduchess of Austria, from Vienna; and two years afterwards an oration in German on the occasion of the empe ror's visit to Italy, Rede auf die Reise Josephs II. in Italien,' 8vo., Wien., 1770. An Explication grammaticale des Prophéties d'Haggée,' by him, appeared in Millin's Magasin Encyclopédique, IIe année, tom. ii., p. 461. ་ (Saxii Onomasticon; Visconti's account of Eckhel in the Biographie Universelle, tom. xii., 8vo., Par. 1814, p. 463467; and the Notitia Literaria de Vitâ et Scriptis J. H. Eckhel, translated from the French of Millin, prefixed to the Addenda ad Doctrinam Numorum Veterum.') ་ ECKMÜHL or EGGMÜHL, a village on the Laber, consisting of about sixteen houses, with a castle, and situated in the Bavarian circle of the Regen, in 48° 47' N. lat., and 12° 3' E. long. It owes its celebrity to the signal victory which the French and Bavarians, under the emperor Napoleon, gained over the Austrians, under the archduke Charles, on the 22nd April, 1809. In testimony of the skill and intrepidity which Marshal Davoust displayed on this occasion, Napoleon conferred the title of prince of Eckmühl upon him. ECLECTICS, the name given to those philosophers who, without adopting any particular system or dogmatizing for themselves, professed to select (ikλéyev) from other philosophical systems whatever they conceived most conformable to truth, and fitted those detached parts together so as to form a new whole. The notion of such a union of jarring systems seems first to have originated with the Neoplatonists, who endeavoured to settle the dispute between themselves and the Peripatetics by the adoption of such parts of the doctrine of Aristotle as could be made to tally with their modification of the academic philosophy. This union of the Aristotelian and Platonic philosophies was attempted first by Potamo of Alexandria, whose principles were taken up and maintained by Ammonius Saccas. It may be doubted however if the title of Eclectics can be properly given to Potamo or Ammonius, the former of whom was in fact merely a Neoplatonist, and the latter rather jumbled together the different systems of Greek philosophy (with the exception of that of Epicurus) than selected the consistent parts of all of them. The most eminent of the followers of Ammonius were Plotinus, Porphyry, Jamblichus, Proclus, and Clemens Alexandrinus; and the antient Eclecticism became at last little more than an attempt to reconcile Platonism with Christianity. The modern and more genuine school of Eclecticism sprung up in the seventeenth century, when Bacon and Descartes flourished. These philosophers refusing to acknowledge themselves members of any particular sect, or to adopt any principle on the mere authority of their predecessors, formed systems for themselves which admitted the doctrines of any other sect without distinction whenever those doctrines were not at variance with what their own investigation had taught them of the nature of things. But modern philosophers have since then formed themselves into new sects, and a new Eclecticism has consequently arisen in our own days, of which the originator was Hegel, and the present supporter Victor Cousin: this newest Eclecticism resembles that of the Alexandrian Platonists in being rather a union of systems than a selection from them, and though it has partisans on the continent, and especially at Berlin, it is not very likely that it will be soon taken up in this country, where persons who read or talk about metaphysics are generally attached to some particular sect of modern philosophy. ECLIPSE (ecleipsis, ikλ), an astronomical phenomenon, being the disappearance of a heavenly body. This may happen in two distinct ways; either the disappearing body may be lost on account of another body coming between it and its source of light, and thus intercepting the light; or the disappearance of a body may be caused by another body coming between it and the spectator. These two sets of circumstances, though ending in the same species of phenomenon, are yet of a character so different that it will be advisable to consider the two in separate articles. We shall therefore here content ourselves with an enumeration of the various kinds of eclipses; leaving further detail, when necessary, to the articles which will be referred to. N M D B X that cone sees no part of AB, and a planet which receives The eclipses in which the disappearance takes place by the removal of the light from the body are 1. The eclipse of the moon. [MOON, ECLIPSE OF.] 2. The disappearance of a portion of Jupiter's surface, occasioned by one of its satellites passing between it and the sun. This is usually called the transit of the satellite's shadow over the disc of Jupiter. [JUPITER.] 3. The eclipses of Jupiter's satellites. [JUPITER.] The eclipses in which the disappearance arises from the absolute interposition of another planet are1. The eclipse of the sun [SUN, ECLIPSE OF], meaning the eclipse of the sun by the moon. 2. The eclipse of the sun (that is, of a very small portion of the sun) by Mercury or by Venus, commonly called the transit of Mercury or Venus over the sun's disc. [MERCURY, TRANSIT OF; VENUS, TRANSIT OF.] 3. The occultation of a fixed star by the moon. [MOON.] 4. The eclipse of a portion of Jupiter by one of its own satellites, or transit of a satellite over the disc. [JUPITER.] 5. The eclipse of a satellite of Jupiter by Jupiter itself, or occultation of a satellite by the planet. [JUPITER.] We have here mentioned such eclipses as are not unfrequent: the only additional phenomenon which we are aware of is the eclipse of a portion of the ring of Saturn by a satellite, or passage of a satellite over the ring, seen by Sir W. Herschel. The satellites of Saturn must suffer eclipses of the first kind by entering the shadows either of the planet or the ring, and of the second kind both from the planet and the ring; but these satellites are only seen with very good telescopes and under very favourable circumstances, so that their eclipses excite little public curiosity. ECLIPTIC. [EQUATOR and ECLIPTIC.] ECLOGUE. [BUCOLICS.] ECONOMISTES. [POLITICAL ECONOMY.] ECPHIMO'TES (Fitzinger), a genus of Saurians, possessing the teeth and pores of the genus Polychrus, but with small scales on the body only. The tail, which is large, has great scales, which are pointed and carinated. The head is covered with plates. The form is a little short and flattened like that of some of the Agama, rather than like the slender shape of Polychrus. Example, Ecphimotes tuberculatus (Agama tuberculata, Spix; Tropidurus torquatus, Pr. Max.) Description.- Ash-coloured, sprinkled with whitish blotches: a demi-collar of black on each side of the neck. Locality, Brazil. ECTOPISTES. [COLUMBIDE, vol. vii., p. 373.] ECTOPISTINEÆ. [COLUMBIDE, vol. vii., p. 373.] ECUADOR is one of the three republics, which, before 1831, constituted the republic of Colombia, but since that time has become a separate government. It comprehends the antient kingdom of Quito, with the plains extending Let us suppose a spherical body AB, which is luminous, and another CD, the smaller of the two, which is not lu-east of it between the Amazon river on the south, and the minous. Let us consider first the circular sections of these bodies made by the plane of the paper, and let common tangents be drawn to these sections, four in number, namely, AX, BY, AM, and BN. If the bodies be very distant from each other, in comparison with their bulk, then it will be sufficient for practical purposes to consider these common tangents as intersecting at A and B, and C and D, the opposite extremities of two parallel diameters. If the whole figure then revolve round the line joining the centre of the two circles, the spherical bodies will be reproduced, together with the conical envelopes by which it may be seen on what the phases of an eclipse depend. The whole space generated by the revolution of Y CDX is, in whole or in part, deprived of the light from AB. Within the space CDZ (or the cone generated by its revolution), the loss of light is total: a spectator situated within P. C., No. 564 Uaupes, the principal branch of the Rio Negro, on the north. Its boundaries are not marked by natural objects, but follow mostly imaginary lines. A line beginning at Tabatinga, on the Amazon, and running due north, along the meridian of 70° 12', divides Ecuador from Brazil as far as 1° 10' N. lat., whence the boundary line runs on this parallel to the Rio Negro. The Rio Negro separates Ecuador from the republic of Venezuela, and the Uaupes forms in the whole length of its course the boundary be tween it and New Granada. Farther west this line extends over the mountain range in which the Rio Magdalena and ridges of the mountain-knot of Los Pastos, and terminates the Rio Cauca originate, then passes over the northern with the lower course of the Rio de los Patias, on the Pacific. The Pacific forms its western boundary. On the south, Ecuador is separated from Peru by a line beginning near VOL. IX.-2 M |