every hour. His diameter is above 67,000 miles, and consequently he is more than 600 times as big as our earth. The inclination of his orbit is said to be 2° 29′ 50′′, and he revolves, according to Herschel, on his axis from West to East in 10 h. 16 m. 2 s. The most remarkable features in the appearance of Saturn, when seen through a telescope, are his satellites and his ring, both of which are to be seen in plate 14, and the latter also in plate 20, fig. 40. The disc of Saturn is likewise crossed by obscure zones, or belts, like those of Jupiter. The satellites, which are five in number, as marked by the round points in their orbits, revolve round the planet in different periods, namely, for the first, or nearest, 0 d. 22 h. 37 m. 23 s.; the second in 1 d. 8 h. 53 m. 9 s.; the third, 1 d. 21 h. 18 m. 27 s.; the fourth, 2 d. 17 h. 44 m. 51 s.; the fifth in 4 d. 12 h. 25 m. 11 s. ;. the sixth, 15 d. 22 h. 41 m. 16 s.; the seventh in 79 d. 7 h. 53 m. 43 s. The ring of Saturn encircles him much in the same manner as the horizon encircles the artificial globe; and when seen through the telescope it appears to be double, being divided into an interior and exterior, as he is represented in fig. 40.

The Georgium Sidus I and his satellites.

The Georgium Sidus (Plate 14) was discovered by Dr. Herschel in 1781, by whom it obtained its name, although on the continent it is better known by the name of Uranus, or Herschel. It is the most distant of all the planets hitherto discovered, its revolution round the sun completing, as is supposed, a period of not less than 83 of our years. The revolutions of its six satellites, according to Herschel, are as follow-for the first, or nearest, 5 d. 21 h. 25 m.; for the second, 8 d. 17 h. 1 m. 19 s.; for the third, 10 d. 23 h. 4 m.; for the fourth, 13 d. 11 h. 5 m. 1 s.; for the fifth, 38 d. 1 h. 49 m.; for the sixth, 107 d. 16 h. 40 m.

The Comets.

The Comets are solid opaque bodies, which, according to Newton, are a kind of planets moving in exceedingly oblique and eccentric orbits, similar to what is represented in plate 14. The train of light which is fre quently observable in them is called its tail; which light is emitted by its nucleus, or Head, that is ignited by the sun. Comets have the appearance of being tailed when they are westward of the sun, and set after him. Others are called bearded, because they emit a light resembling a beard in appearance when they are eastward of the sun; and others are termed hairy, when their light resembles hair, as when the sun and comet are diametrically opposite.

Practical Astronomy.

Practical astronomy comprehends that part of the science which may be learned by the means of machines or instruments, of which the principal are the Globes, the Orrery, and the Astronomical Quadrant.

The Use of the Globes.

A Globe is an artificial representation of any sphere, and is of two kinds, namely, terrestrial, which gives a representation of the earth, and celestial, that which represents the heavens, as may be seen in plate 20, fig. 43. The parts of the globes, and their several uses, are as follow :

Axis. The axis is a brass wire, as A, on which the body of the globe is made to turn, so as to represent the motion of the earth or the heavens on their own axis, the two extremities of which, N and S, are the North and South poles.

The brazen Meridian, M, is a strong brass ring which encompasses the globe from North to South. The use of the Meridian is as follows:-1. It divides the globe into two hemispheres, East and West, in the former of which all bodies rise, and in the latter they set; by which both the diurnal and nocturnal arcs are divided into two equal portions, making forenoon, noon, afternoon, and midnight. Each of these four quadrants of the circle consists of 90 degrees, namely, two numbered from the equator to the poles, and the other two from the poles to the equator, as in plate 20, fig. 42. 2. It measures the greatest altitude of the heavenly bodies; on that account called their Meridian altitude. 3. It measures the elevation of the pole in an oblique and parallel sphere. 4. In a right sphere, being in the place of the horizon, it determines the right ascension of the celestial bodies. 5. It measures the declination of the heavenly bodies when they are brought to its graduated edge. The declination of the sun is thus measured by means of his place in the ecliptic, i. e. the sign and degree he is in on any given day, as marked on the horizon. 6. It measures the latitude of all places on the terrestrial globe by means of the degrees and minutes thereon marked, and also the longitude of places as marked on the equator, by showing the point where the latter is intersected by it. 7. It serves for the solution of all problems where the globe requires to be rectified for the latitude of the place, or for the sun's place. When the pole, North or South, is elevated above the horizon any number of degrees, equal to the latitude of the place, or the declination of the sun, the globe is said to be rectified for the latitude and sun's place; but in the latter case the index, or hour circle, must be turned to twelve, or noon. 8. It answers as a general meridian for all the meridian circles which are drawn on the globe at the distance of fifteen degrees from each other; and by it also parallels of latitude may be drawn on the globe at the smallest possible distance from each other. Horizon. The Horizon, or rational Horizon, H, is the frame which supports the globe, and is divided into several concentric spaces, containing a calender of the months and days, corresponding to the 12 zodiacal constellations, each divided into 30 parts. In most globes the circle of bearings follows, marked with the cardinal and collateral points of the compass, also the circle of azemuths and amplitudes. The use of the Horizon is as follows:-1. It divides the globe into two hemispheres, upper and lower, i. e. northern and southern, and cuts the meridian at right angles. 2. It is the circle from which the altitudes of the poles and of the heavenly bo` dies are reckoned. 3. It determines the true rising and setting of the celestial bodies, as also their course above and below itself, which is called the artificial day and night. 4. Not only the four cardinal points, North, South, East, and West, but also four other points are marked upon it namely, the rising and setting points in the two solstices. 5. It measures the amplitude of the heavenly bodies, which is an arc of the horizon intercepted between the true East or West points and the centre of the sun or stars at their rising or setting, according to their dif ferent declinations and latitudes. 6. It is the circle in which are marked the regions or points in the sphere, from which the winds derive their names; whence these points are called the points of the compass. 7. It measures the ascensions and descensions of the heavenly bodies, &c.

Horary Circle. The Horary, or Hour Circle, is a small circle of brass, as in fig. 43, which is usually divided into twice 12 hours, the upper of which represents noon, and the lower midnight. This circle is divided so that

the hours should correspond to the meridian circles, otherwise called horary circles, drawn on the globe, as M m m, &c., plate 20, fig. 41, reckoning an hour of time equal to fifteen degrees of longitude. Quadrant of Altitude. The Quadrant of Altitude is a thin flexible piece of brass, so formed at one end, with the assistance of a screw, as to fix on any part of the horizon: it is so called because it measures the altitudes of celestial bodies, and serves the purpose of the vertical circles which are not drawn on the globe. It is divided upwards from 0 to 90 degrees, and downwards from 0 to 18 degrees. The upper divisions are used to determine the distances of places on the terrestrial globe, or the distances, altitudes, &c. of the celestial bodies on the celestial globe: for this purpose the quadrant must be screwed upon the brass meridian over the latitude of any given place, which is called rectifying for the zenith; for supposing the pole to be elevated so many degrees above the horizon as are equal to the latitude of the place, then the same degree on the meridian, reckoned from the equator, is the zenith point. The lower division serves to measure the beginning, end, and duration of twilight.

Equator. The Equator on the terrestrial globe, or Equinoctial on the celestial, has the degrees and minutes marked upon it (as E in fig. 42), 180 degrees each way, i. e. Eastward and Westward, or 360 degrees quite round, numbered from a given point, called the first meridian, for which that which passes through the capital of the country is generally chosen. The use of the Equator is as follows:-1. It divides the globe into two equal parts, called the Northern and Southern hemispheres, every part of which is 90 degrees distant from the poles. 2. It intersects the ecliptic at two points, called the equinoctial points, namely, Aries and Libra. Whenever the sun comes to these points, the days and nights are equal all over the world; wherefore these periods are called the Equinoxes. 3. From this circle the declination of the sun or stars on the celestial globe, or the latitude of places on the terrestrial, are reckoned on the meridian. 4. On this circle are reckoned the right and oblique ascensions on the celestial globe, and the longitude of places on the terrestrial. Ecliptic. The Ecliptic, e in fig. 41, and C P in plate 13, fig. 7, is the circle so called because eclipses of the sun and moon happen only within that circle. The use of the ecliptic is as follows:-1. It cuts the equator at two opposite points, making an angle of 234, called the obliquity of the ecliptic. 2. By this obliquity of the ecliptic is determined the greatest declination of the sun, as well as the distance of the tropics from the equator, and the poles of the ecliptic from the poles of the equator. 3. It is divided into the twelve portions of thirty degrees, corresponding to the days of the month, which are distinguished by the signs of the zodiac. 4. In this circle the sun advances one degree every 24 hours, and thirty degrees every month, passing through the whole 360 degrees in a year; whence it is called the sun's path. 5. From this circle is measured the latitude of the stars.

Zodiac. The Zodiac is the broad belt or circle drawn on the celestial globe at the distance of about eight degrees on each side the ecliptic, E, which marks the boundary within which the planets perform their revolutions. Colures. The Colures divide the ecliptic into four equal parts, and mark the four seasons of the year. The meridian, A E B Q, in pl. 13, fig. 7, represents the solstitial colure.

By the help of the lesser circles the terrestrial globe is divided into different portions called Zones, which are

large, and Climates, which are small portions. The zones are five in number; namely, two frigid, two temperate, and one torrid. The North frigid zone lies within the arctie circle, TM, in fig. 7; and South frigid zone within the antarctic circle. The North temperate zone extends from the arctic circle to the tropic of Cancer, CR; the South temperate zone from the antarctic circle to the tropic of Capricorn, K P. The torrid zone lies between the tropics. Climates are portions of the earth, contained between two small circles parallel to the equator, of such a breadth that the longest day in the parallel nearest the pole exceeds the longest day in the parallel of latitude nearest the equator, by half an hour, in the torrid and temperate zones, and by a month in the frigid zones; so that there are twenty-four climates between the equator and each polar circle, and six climates between each polar circle and its poles.

The inhabitants of the earth are likewise distinguished, by their relative situations with regard to each other, into Antoeci, Perioeci, and Antipodes. The Antoeci are those who live in the same degree of longitude, and in equal degrees of latitude, but the one North and the other South: they have noon at the same time, but contrary seasons of the year; consequently, the length of the days to the one is equal to the length of the nights to the other. Perioeci are those who live in the same latitude, but in opposite longitudes; consequently, when it is noon with the one it is midnight with the other: they have the same seasons of the year, and the same lengths of days. Antipodes are those who live diametrically opposite to each other; their latitudes, longitudes, seasons of the year, days, nights, being all contrary. There are other distinctions of the inhabitants into Amphiscii, Heteroscii, and Periscii, according to the manner in which their shadows fall. [vide Amphiscii, &c.]

The Orrery.

The Orrery is a machine which has been contrived to display the solar system with the order, motions, excentricities, and other affections of the sun and the planets. It has been constructed in a variety of forms more or less complete, but the one which is given in plate 20, fig. 45, affords the best representation of the planets that can be given on paper.

Astronomical Quadrant.

This instrument is so called because it is constructed for the purpose of taking observations of the heavenly bodies. It is usually made of brass or iron bars, having its limb A B, pl. 19, fig. 39, divided into degrees and minutes, and furnished either with two pair of plain sights, or two telescopes, one on each side of the quadrant, as C D and E F, moveable about the centre by means of the screw G; the dented wheels H and I serve to direct the instrument to any object of which the observer wishes to take the altitude, &c. This quadrant is sometimes provided with only one telescope, and a plummet to direct its movements.

Principal Writers on Astronomy in Chronological
Succession.

Plato "Dialogi de Astronomia ;" Aristoteles "De Cœlo ;" Eratosthenes "De Characterismis Astrorum;" Aratus "De Apparentiis;" Hipparchi Bithyni "Enarrationum in Arati et Eudoxi Phænomena tres libri;" Gemini Isagoge in Arati Phenomena seu Elementa Astronomica;" Theodosius "De Sphærâ;" Cleomedes "De Sphærâ;" Manilii "Astronomicon Poeticon;" Dionysius Areopagita" De Eclipsi in Morte Christi ;" Hygini

"Astronomicon Poeticon;" Plinii "Historiæ naturalis, 1. 1," &c.; Procli "Commentarii in Euclidem;" ProLEMEI" Almagestum," &c.; Theonis patris Hypatice "Commentarii in Ptolemæum;" Martianus Capella " De Nuptiis Mercuriæ et Philologiæ," &c.; Achillis Tatii "Isagoge in Arati Phænomena;" Albategnus "De Scientia Stellarum ;" Alfragani" Elementa Astronomica;" Johannes de Sacrobosco "De Sphærâ;" Alphonsi X. Regis "Tabulæ;" Purbachii "Epitome Ptolomæi Almagesti," &c.; Regiomantanus" De Cometis," &c.; Pontanus "De Rebus Cœlestibus ;" Stoefleri"Commentarii in Proclum ;" Copernicus "De Revolutionibus;" Tycho Brahe "De Mechanica Astronomiæ," &c.; Clavii "Kalendarii Reformatio," &c.; Josephus Scaliger "De Cyclometria," &c.; Kepleri "Rudolphina Tabulæ, Epitome Astronomia Copernici," &c.; Bayeri "Uranometria ;" Riccioli "Almagestum novum ; Hevelii "Machina cælestis," &c.; Newtonis Principia," &c.; Flamstead's "Historia cœlestis Britannica;" Cassini "Recueil d'Observations," &c.; Gregorii "Elementa Astronomiæ," &c.

ASTRO'SCOPE (Astron.) a kind of astronomical instrument composed of telescopes for the observation of the stars, invented and described by William Shukhard, of Tubingen, in 1698.

ASTROSCOPΙΑ (Astron.) from ἄκρον and σκέπτομαι, speculor; observation and contemplation of the stars. ASTROTHE'SIA (Astron.) the same as Astrum. A'STRUM (Astron.) or Astron, a constellation or assemblage of stars, in distinction from aster, a single star. ASTRUM (Chem.) the virtue and power which accrues to things from their preparation, as the astrum of salt, its resolution with water or oil. Dict. Paracelsic. ASTRUM (Med.) troches in the form of an asterisk. Gal. de Comp. Med. sec loc. 1. 8, c. 3.

Placit.

ASTRUM (Law) a house or place of habitation.
Hilar. 18 Ed. 1.
A'SYLA (Bot.) a herb with which cattle cure themselves
when they have eaten pimpernel. Plin. 1. 27, c. 13.
ASY'LUM (Ant.) ovo, from a, priv. and ruxw, to vio-
late, i. e. an inviolable place, or a place of refuge for
offenders, where they were screened from the hands of
justice. The asyla, among the Jews, were the temple, the
altar of burnt offering, and the cities of refuge mentioned
in Exodus xxi. 33, and Numbers xxxi. 11. A similar
custom prevailed both among the Greeks and the Romans,
where temples, altars, and statues, were places of refuge
for criminals of every description, as Tacitus informs us,
to the violation of public justice. It is said that the first
asylum was erected, at Athens, by the Heraclidæ, for the
protection of those who dreaded the resentment of such
as had suffered from the oppression and tyranny of their
grandfather Hercules. The tomb of Theseus was an
asylum for slaves; the temple of Diana, at Ephesus, an
asylum for debtors. At the building of Rome, Romulus
left a space as a place of refuge for all sorts of persons,
slaves or free-born, who wished to settle under his govern-
ment to which Virgil and Juvenal allude.
Virg. En. 1. 8, v. 342.

Hinc lucum ingentem, quem Romulus acer asylum
Rettulit.

Damascus, Heraclea, Laodicea, Antioch, Samosata, &c. bearing the inscription IEPA KAI ACTAOC, i. e. sacred and inviolable. Dionys. Hal. 1. 2; Liv. 1. 35, c. 51; Tacit. Annal. 1. 3, c. 60; Plut. de Superstit. et de Vitand. Usur.; Sueton. in Tib. c. 37; Non. Marcell. 1. 1, c. 209; Serv. in En.; Vaillant. Numis. Græc.; Spanheim. de Præst. et Us. Numm. Dissert. 9, p. 778, &c. ASYMMETRY (Math.) ví, a relation between two quantities, having no common measure, as between 1 and the 2.

ASYMPTOTE (Meth.) cúμлTwτor, a name for lines continually approaching each other, but which, if infinitely produced, can never meet, so called from a, priv. and Ti, to meet; or, in other words, a tangent to the curve when conceived to be at an infinite distance, which is best illustrated by the asymptote of the conchoid, as in the subjoined figure: suppose A B C to be part of a

conchoid, and the line MN be so drawn that the parts FB, GC, HD, I E, &c. of right lines drawn from the pole P to the curve B C D, be equal to each other, then will the line M N be the asymptote of the curve, because the perpendicular Cc is shorter than F B, and Dd than Cc, &c. so that two lines continually approach, yet the points Fe, &c. can never coincide.-Of curves of the first kind, that is, the Conic Sections, only the hyperbola has more than one asymptote; all curves of the second kind have one at least, and may have three; and all curves of the fourth kind may have four. The conchoid, cissoid, and logarithmic curve have each one.-Asymptotes of the hyperbola are thus described; suppose, as in the annexed figure, C P to be a diameter of an hyperbola, RAS and CD the semiconjugate to it; then, if F E be a tangent at the point A, AE = FA

CD, and the lines C G, CG, be drawn from the centre C through the points E and F, these lines C G, CG, will be the asymptotes GR of the hyperbola R A S.

D

C

E

F

A

P

G

Apollon. Perg. Con. Sect. 1. 2, prop. 1, &c. ASYMPTOTON (Med.) Tato, i. e. not meeting, not compressed or brought into contact. Hippocrat. i xuâ; Gal. ad Glauc. 1. 1.

ASYNDETON (Rhet.) rudero, from a, priv. and curdea, to bind; a figure in which many words are joined without a conjunction, as veni, vidi, vici. Dionys. Hal. in Jud. Lys. c. 9; Sophron. apud Phot. Cod. 5; Philostrat. in Vit. Antiph.; Schol. in Aphthon. Progymn. de Ethopoeia. A'TABAL (Mus.) a kind of tabor used among the Moors, which is probably a word of Moorish extraction. ATAMA'RAM (Bot.) the Annona squamosa of Linnæus. ATAMA'SCO (Bot.) a species of the Amaryllis of Linnæus. ATARA'XIA (Ant.) another name for stoical apathy, from a, priv. Tapáσow, to disturb.

ATAXIA (Med.) ratia, from a, priv. and row, to dispose, irregularity; a term applied to the pulse or to fevers. Hipp. Epidem. 1. 1 & 3.

A'TCHE (Com.) the smallest coin in the Grand Seignor's dominions equal to 3 of a farthing.

ATCHIEVEMENT (Her.) vulgarly called hatchment, the arms of any family, with all the ornaments belonging to their several degrees, as crest, helmet, mantle, &c. or of

'

rinus; sometimes from the ayavelirai, who presided at musical contests. ATHWA'RT (Mar.) an epithet, used in several phrases to signify a cross, the line of the ship's course, as We discovered a fleet standing athwart us.' "Athwart the forefoot" is applied to the flight of a cannon ball, fired from one ship across the line of another's course, but a-head of her to bring her to. "Athwart hawse" expresses the situation of a ship when she is driven by wind or tide across the stern of another vessel, whether in contact, or at a small distance from each other. "Athwart ships," reaching across the ship from one side to the other. ATHYMIA (Med.) from a, priv. and us, the mind; dejection of spirits attendant upon some diseases. ATIA (Law) a writ of inquiry, whether a person be committed to prison on just cause of suspicion. [vide Odio et Atia]

A'TIBAR (Com.) Gold dust on the coast of Africa. ATILIA Lex (Ant.) the name of several laws enacted by members of the Atilian family, as 1, by Atilius, a tribune, concerning the towns which surrendered themselves, U. C. 543. Liv. 1. 26, c. 33. 2. Concerning the guardians, U.C. 567. Ulp. in Fragm. 3. Concerning the military tribunes, passed by L. Atilius and C. Marcius, tribunes of the people. Liv. I. 9, c. 30.

ATILIA (Archæol.) Utensils or country implements.
ATI'NIA (Bot.) a sort of Elm. Plin. l. 16, c. 17.
ATINIA lex (Ant.) a law which gave the tribunes the privi-
lege of a senator. Aul. Gell. 1. 45, c. 8.

ATIZOES (Min.) a precious stone, shining like silver, three fingers in size. Plin. 1. 37, c. 10.

ATLANTES (Archæol.) Tharts, from arhaw, to bear; images of men bearing up pillars, or supporting the building; as Atlas bore the heavens on his shoulders. Vitruv. 1. 6, c. 10.

ATLANTIDES (Astron.) another name for the Pleiades. ATLANTIUS nodus (Bot.) the first or bottom joint of the thorn which bears up the rest. Plin. 1. 28, c. 8.

ATLAS (Geog.) the name of a book, containing maps of the whole world; so called from Atlas, who was fabled to have borne the world on his shoulders.

A'TLAS (Anat.) the first vertebra of the neck which supports the head.

ATLAS (Com.) a satin manufactured in the Indies. Mort. ATMOSPHERE (Nat.) from rus, vapour, and Qaipa, a sphere or region; signifies properly that region of the air next to the earth, which receives the vapours and exhalations, and is terminated by the refraction of the sun's light. In this sense, it is most commonly understood by natural philosophers; although sometimes it is made to signify the whole mass of ambient air.-Atmosphere of consistent bodies, according to Mr. Boyle, is a kind of sphere, formed by the effluvia emitted from them. ATMOSPHERE (Elect.) that sphere which surrounds the surface of electrified bodies, and is formed by the effluvia issuing from them.-Magnetic atmosphere, that sphere within which the virtue of the magnet acts. ATMOSPHERIC Stones (Nat.) vide Aeroliths. Atmospheric Tides, certain eriodical changes in the atmosphere, similar to those of the ocean, and produced from nearly the same causes; of this description are the Equinoctial winds.

ATMOSPHERICAL clock (Mech.) a machine for measuring the mean temperature of the air, which was proposed by Dr. Brewster.

ATA'CIUM (Bot.) a name for Antirrhinum.

ATO'CIUM (Med.) vónov, a medicine which prevents conception.

ATOLLI (Med.) a sort of Indian pap, made of maize, ΑΤΟΜ (Nat.) άτομος, sc., ἐσια, individua substantia quæ

secari non potest; a thing so small that it cannot be divided. A'TONY (Med.) arovia, from a, priv. and rew, to extend; a want of due tension, or a relaxation of the system. A'TRA bilis (Med.) Black-Bile, or Melancholy, properly signifies that humour of the body which is rendered, by adustion, preternaturally mordacious, harsh, and malignant. Aret. de Sign. et Caus. Acut. Morb. 1. 1, c. 5; Ruf. Ephes. 1. 1, c. 3; Gal. Comm. in Hippoc. Epidem. 1. 1, &c. ATRACTYLIS (Bot.) arpantonis, distaff-thistle, a plant; so called from páros, a spindle, because the spindle was formerly made of it. Its leaves, when taken by decoction, are aperitive, sudorific, and an antidote against poisons. Theoph. Hist. Plant. 1. 6, c. 4; Dioscor. 1. 3, c. 107; Plin. 1. 21, c. 15, &c.; Gal. de Simpl. 1. 6; Oribas. Med. Collect. 1. 15; Aet. Tetrab. 1, serm. I; Paul. Æginet. 1. 7, c. 3. ATRACTYLIS, in the Linnean system, a genus of plants, Class 19 Syngenesia, Order 1 Polygamia Equalis. Generic Characters. CAL. outer many-leaved.-COR. compound radiate.-STAM. filaments five; anther cylindric. -PIST. germ very short; style filiform; stigma bifid.PER. none; seeds turbinate; receptacle villose. Species. The species are some annuals, as-Atractylis cancellata, Acarna, Eryngium, seu Carduus, Netted Atractylis. Some biennials, as-Atractylis humilis, Centaurea, Cnicus, seu crocodeloides, Dwarf Atractylis. Some perennials, as-Atractylis gummifera, Cnicus, Carlina, Carduus, seu Chameleon, Gummy-rooted Atractylis, &c. Dodon. Stirp. Hist.; Clus. Hist. rar. Plant.; J. Bauh. Hist. Plant.; C. Bauh. Pin.; Park. Theat. Botan.; Raii Hist. Plant.; Tournef. Inst.

ATRAG'ENE (Bot.) Traveller's joy, a plant, the flowers, bark, seeds, and root of which are of a caustic quality. ATRAGENE, in the Linnean system, a genus of plants, Class 13 Polyandria, Order 7 Polygynia.

Generic Characters. CAL. perianth four-leaved.-COR.. petals twelve.-STAM. filaments very many; anthers oblong.-PIST. germs very many; styles villose; stigma simple.-PER. none; seeds very many.

Species. The species are shrubs, as-Atragene Japonica, Atragene Alpina, Clematis, Capensis, seu Pulsatilla, Zeylanica. Clus. Hist. rar. Plant.; J. Bauh. Hist.; C. Bauh. Pin.; Ger. Herb.; Park. Theat. Bot.; Raii Hist. Plant.

ATRAMENTUM (Nat.) the blood of the Cuttle-fish. ATRAMENTUM Sutorium (Chem.) xáλxavées, Copperas or Vitriol. Cic. de Nat. Deor. 1. 2, c. 50; Plin. 1. 34, c. 12; Oribas. Med. Collect. 1. 13.

ATRAPHA'XIS (Bot.) the Greek name for the Atriplex. ATRAPHAXIS, in the Linnean system, a genus of plants, Class 6 Hexandria, Order 2 Digynia.

Generic Characters. CAL. perianth two-leaved.-COR. petals two.-STAM. filaments six; anthers roundish.

PIST. germ compressed; style none; stigmas two capitate. PER. none; seed one." Species. The two species are-Atraphaxis spinosa, seu Atriplex, Prickly branched Atraphaxis, a shrub, native of Siberia.-Atraphaxis undulata, Polygonum, seu Arbuscula, Waved-leaved Atraphaxis, a shrub, native of the Cape of Good Hope. Tournef. Inst. Re. Herb; Boerhaav. Ind. ATREBATICÆ Vestes (Ant.) χιτῶνες ἀτριβατικοί, a sort of cloths made at Arras, in Flanders. Suidas.; Cal. Rhodig. Ant. Lect. l. 16, c. 10.

ATRICES (Med.) Small tubercles about the anus. A'TRICI (Med.) small sinuses in the intestinum rectum. ATRIENSIS (Ant.) custodes Atri; servants of special trust, who had the charge of the images, plate, and pedigree of the family which were kept in the porch, or hall. Plaut. Asin. act. 2, scen. 2, v. 84.