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volume under the title of “Marmora Arundeliana," containing nearly forty inscriptions with annotations. During the civil wars, these marbles were defaced and much injured, and some of them entirely lost, or made use of for the ordinary purposes of building. In 1667, what were left of these curious remains were presented to the University of Oxford, when a new edition of Selden's work was published, with additional notes, by the celebrated Dr. Prideaux. Mr. Mattaire in 1731, gave the public a more comprehensive view of these marbles, and in 1763, Dr. Chandler published a new and improved copy of them, in which he corrected the errors of the former editors, and supplied the deficiencies in some of the inscriptions, particularly those of the Parian chronicle, by many ingenious conjectures. These marbles, in their perfect state, contained a chronological detail of the principal events of Greece, from the commencement of the reign of Cecrops, in the year before Christ 1582, to the close of the archonate of Diognetus, in the year 264, A. C. The chronicle of the last 90 years is lost, and the others are much defaced and corroded, of course the sense can only be discovered by very learned and industrious antiquaries, or supplied by conjectures. Almost every event in this table between the destruction of Troy and the annual magistracy of Athens, is dated 26 years earlier than in the camous of Eusebius, and those of other approved chronologers. These marbles have been applied to the elucidation of many parts of ancient history; but their inconsistency with other authentic records, has depreciated their value and use. Their authenticity has been doubted, and the question ably discussed by Mr. Robertson and Mr. Hewlett, the former being inclined to give up, and the latter to vindicate the authenticity of the Parian chronicle. ARUNDO, common reed, in botany, a genus of the Triandria Digynia class of plants, the calyx of which is a glume formed of two oblong, acuminated valves, not aristated, one longer than the other. The corolla is formed of two valves of the length of the cup, of an oblong, acuminated figure, with a lanuginous matter at the base, of the length of the flower; the corolla adheres to the seed, and serves as a pericarpium; the seed is single, oblong, pointed, and downy at the base. There are 14 spe
cies, of which we notice 1. A. bambos, bamboo-cane, which has a woody, hollow, round, straight culm, forty-feet high and upwards, simple and shining; it grows naturally almost every where within the tropical regions. Over a great part of Asia it is very common. It has been long cultivated here. Some of the plants have been seen twenty feet high; a strong shoot from the root has been known to grow twenty feet in five or six weeks. See BAM boo. 2. A. phragmites, the common reed, which flowers from July to September, and is common by the sides of rivers, in ditches, and large standing waters. In autumn, when the leaves begin to fall, and the stems are changed brown, it is cut for making screens in kitchen gardens, and for many other uses, as thatching, for which it is more durable than straw; for ceilings, and to lay across the frame of wood-work as the foundation for plaister floors. The panicles are used by the country people in Sweden to dye wool green. ARUSPICES, or HARUspices, an order of priesthood, among the Romans, that pretended to foretel future events by inspecting the entrails of victims killed in sacrifice; they were also consulted on occasion of portents and prodigies. It appears that women were admitted into this order. AS, in antiquity, a particular weight, consisting of twelve ounces; being the same with libra, or the Roman pound. As was also the name of a Roman coin, which was of different matter and weight, according to the different ages of the commonwealth. It is also used to signify an integer, divisible into twelve parts, from which last acceptation it signified a whole inheritance. The as had several divisions, the principal of which were the uncia, or ounce, being the twelfth part of the as; sextans, the sixth part of the as ; quadrans, the fourth part; triens, the third part; and semis, half the as, or six ounces. Bes was two thirds of the as, or eight ounces; and dodrans, threefourths of the as. ASAFCETli) A, in chemistry, a gum resin obtained from ferula asafoetida, a perennial plant which is a native of Persia. When the plant is about four years old its roots are dug up and cleaned, and from their extremity when cut, a milky juice exudes, which soon hardens and constitutes asafoetida. It comes into this and other countries in Europe in small grains
of different colours, hard and brittle. Its taste is acrid and bitter, its smell is strongly alliaceous and fetid. Alcohol dissolves iths of this substance, and water takes up about 4th, if applied before the spirit. It yields an oil when distilled with water and alcohol. The specific gravity is 1.32. ASARUM, or Asar ABAccA, in botany, a genus of plants without any flower-leaves, and belonging to the Dodecandria Monogynia class of Linnaeus. Its fruit is a coriaceous capsule, divided into six cells, and containing a great many oval seeds. There are three species. The common asarabacca is a native of many parts of Europe, in woods and shady places, flowering in April and May. With us it is found only in Lancashire. The root finely powdered excites vomiting; coarsely powdered it purges. The powder of the leaves is the basis of most cephalic snuffs, which occasion a considerable discharge of mucus from the nostrils without much sneezing. ASBESTUS, in mineralogy, a species of the Talc family, well known to the ancients, who made a kind of cloth from one of the varieties, which was famous for its incombustibility. It is found in primitive mountains, especially in serpentine, which it traverses in veins. It is divided by Werner into four sub-species, viz. 1. The elastic asbest, or rock cork, which is of a yellowish grey, of various intensity: occurs sometimes massive, sometimes in plates, and with impressions. At first sight it appears to be fine grained, uneven. Opaque very seldom; translucent on the edges; somewhat elastically flexible; cracks when handled. Specific gravity .09 to .068. 2. The amianthus, of a greenish white, passing into a greenish grey, sometimes blood red. Massive, also in plates and small veins, and in capillary crystals. Internally its lustre is glistening, passing to shining: fracture parallelly fibrous, and sometimes a little curved. It is found in primitive rocks, in Sweden, Bohemia, Silesia, Italy, Hungary, Siberia, France, Spain, and Scotland. From its flexibility, and its resisting the effects of fire, it is said to have been by the ancients woven into a kind of cloth, in which they wrapped the bodies of persons of distinction before they were placed on the funeral pile, that their ashes might be collected free from admixture. It was also used for incombustible wicks; but is now considered only as an object of curiosity. To these may be added, 3. The common asbestus; and 4. The rock
ASCARIS, in natural history, a genus of worms of the order Intestina. Body round, elastic, and tapering towards each extremity; head with three vesicles; tail obtuse or subulate; intestines spiral: milk white and pellucid. There are about 80 species; separated into divisions, riz. A. infesting mammalia; B. found in birds; C. infesting reptiles; D. infesting fish; and E. infesting worms. A. vermicularis: head subulate; skin at the sides of the body very finely crenate, or wrinkled: inhabits the intestines of children and thin people, principally in the rectum. They are generally found in considerable numbers, and occasion many troublesome symptoms, creeping sometimes up into the stomach. They are viviparous, and about half an inch long. The female has a small punctiform aperture a little below the head, through which the young are protruded. A. lumbricus, inhabits the intestines of thin persons, generally about the ileum, but sometimes ascends into the stomach, and creeps out of the mouth and nostrils. They are frequently very numerous and vivacious, from twelve to fifteen inches long : body transparent, of a light yellow, and with a faint line down the side. They are oviparous, and distinguished from the earth worm, in wanting the fleshy ring below the head, and in having three vesicles.
ASCENSION, in astronomy, the rising of the sun or a star, or any part of the equinoctial with it, above the horizon: is either right or oblique.
Right ascension is that degree of the equator, reckoned from the beginning of Aries, which rises with the sun or a star, in a
right sphere. It is found by the following proportion. As the radius to the cosine of the sun or star's greatest declination, so is the tangent of the distance from Aries to Libra, to the tangent of right ascension. Oblique ascension is that degree and minute of the equinoctial, counting from the beginning of Aries, which rises with the centre of the sun or a star, or which comes to the horizon at the same time as the sun or star, in an oblique sphere. In order to find the oblique ascension we must first find the ascensional difference.
The arch of right ascension coincides with.
the right ascension itself, and is the same in all parts of the globe. The arch of oblique ascension coincides with the oblique ascension, and changes according to the latitude of places. The sun's right ascension in time is useful to the practical astronomer in regular observatories, who adjusts his clock by sidereal time. It serves also for converting apparent into sidereal time; as e. g. that of an eclipse of Jupiter's satellites, in order to know at what time it may be expected to happen by his clocks. For this purpose, the sun's right ascension at the preceding noon, together with the increase of right ascension from noon, must be added to the apparent time of the phenomenon set down in the ephemeris. The sun's right ascension in time serves also for computing the apparent time of a known star's passing the meridian: thus, subtract the sun's right ascension in time at noon from the star's right ascension in time, the remainder is the apparent time of the star's passing the meridian nearly; from which the proportional part of the daily increase of the sun's right ascension from this apparent time from noon being subtracted, leaves the correct time of the star's passing the meridian.The sun's right ascension in time is also useful for computing the time of the moon and planets passing the meridian. The practical method of finding the right ascension of a body from that of a fixed star, by a clock adjusted to sideral time, is this: let the clock begin its motion from Oh 0' 0" at the instant the first point of Aries is on the meridian; then, when any star comes to the meridian, the clock would shew the apparent right ascension of the star, the right ascension being estimated in time at the rate of 15° an hour, provided the clock was subject to no error, because it would then shew at any time how far the first point of Aries was from the meridian. But as the clock is liable to err, we must be able at
any time to ascertain its error, or the dif.
ference between the right ascension shewn
by the clock and the right ascension of that
point of the equator which is at that time on
the meridian. To do this we must, when a
star, whose right ascension is known, passes
the meridian, compare its apparent right as
cension with the right ascension shewn by
the clock, and the difference will shew the error of the clock. E.g. Let the apparent right ascension of Aldebaran be 4° 23' 50"
at the time when its transit over the meridian is observed by the clock; and suppose the time shewn by the clock to be 4° 23'52", then there is an error of 2" in the clock, as it gives the right ascension of the star 2"
more than it ought. If the clock be compared with several stars, and the mean error taken, we shall have more accurately the error at the mean time of all the observations. These observations, being repeated every day, will give the rate of the clock's going, or shew how much it gains or loses. The error of the clock and the rate of its going being thus ascertained, if the time of the transit of any body be observed, and the error of the clock at the time be applied, we shall have the right ascension of the body. This is the method by which the right ascension of the sun, moon, and plamets are regularly found in observatories. To find the right ascensions mechanically by the globe, see Globes, the use of. The arch of right ascension is that portion of the equator intercepted between the beginning of Aries and the point of the equator which is in the meridian: or it is the number of degrees contained in it. This coincides with the right ascension itself. The right ascension is the same in all parts of the globe. We sometimes also say, the right ascension of a point of the ecliptic, or any other point of the heavens. The right ascension of the mid-heaven is often used by astronomers, particularly in calculating eclipses by the nonagesimal degree; and it denotes the right ascension of that point of the equator which is in the meridian, and is equal to the sum of the sun's right ascension and the horary angle or true time reduced to degrees, or to the sum of the mean longitude of the sun and mean time.
ASCENSIONAL difference, the difference between the right and oblique ascension in any point of the heavens; or it is the space of time that the sun rises or sets before or after six o'clock.
The ascensional difference may be found by this proportion, viz. As the radius is to
the latitude of the place, so is the tangent of the sun's declination to the sine of the ascensional difference; by subtracting of which from the right ascension, when the sun is in the northern signs, and adding it, when the sun is in the southern ones, you will find the oblique ascension. ASCENT of fluids is particularly understood of their rising above their own level, between the surfaces of nearly contiguous bodies, or in slender capillary glass tubes, or in vessels filled with sand, ashes, or the like porous substances. This effect happens as well in vacuo as in the open air, and in crooked as well as straight tubes. Some liquors, as spirit of wine and oil of turpentine, ascend with greater celerity than others; and some rise after a different manner from others. Mercury does not ascend at all, but rather subsides. Upon the same principle, two smooth polished plates of glass, metal, stone, or other matter, being so disposed as to be almost contiguous, have the effect of several parallel capillary tubes; and the fluid rises in them accordingly: the like may be said of a vessel filled with sand, &c. the divers little interstices of which form as it were a kind of capillary tubes: so that the same principle accounts for the appearance in them all. And to the same may probably be ascribed the ascent of the sap in vegetables. Thus Sir I. Newton says, if a large pipe of glass be filled with sifted ashes, well pressed together, and one end dipped into stagnant water, the fluid will ascend slowly in the ashes, so as in the space of a week or fortnight to reach the height of 30 or 40 inches above the stagnant water. This ascent is wholly owing to the action of those particles of the ashes which are upon the surface of the elevated water; those within the water attracting as much downwards as upwards: it follows, that the action of such particles is very strong; though being less dense and close than those of the glass, their action is not equal to that of glass, which keeps quicksilver suspended to the height of 60 or 70 inches, and therefore acts with a force which would keep water suspended to the height of about 60 feet. By the same principle a sponge sucks in water; and the glands in the bodies of animals, according to their several natures and dispositions, imbibe various juices from the blood. If a drop of oil, water, or other fluid, be laid on a glass plane, perpendicular to the horizon, so as to stand without breaking or running off, and another plane inclined to the formerso as to meet at top, be brought to touch
the drop, then will the drop break, and ascend towards the touching end of the planes; and it will ascend the faster in proportion as it is higher, because the distance between the planes is constantly decreasing. After the same manner the drop may be brought to any part of the planes, either upward, or downward, or sideways, by altering the angle of inclination. Lastly, if the same perpendicular planes be so placed as that two of their sides meet, and form a small angle, the other two only being kept apart by the interposition of some thin body, and thus immerged in a fluid tinged with some colour; the fluid will ascend between the planes, and this the highest where the planes are nearest, so as to form a curve line, which is found to be a just hyperbola, one of the asymptotes whereof is the line of the fluid, the other being a line drawn along the touching sides. The physical cause in all these phenomena is the same power of attraction.
ASCIDIA, in natural history, a genus of worms, of the order Mollusca. Body fixed, roundish, and apparently issuing from a sheath: two apertures, generally placed near the upper end, one beneath the other. There are more than 40 species found in the sea, adhering by their base to rocks, shells, and other submarine substances. They are more or less gelatinous, and have the power of squirting out the water which they take in. Some of them are esculent: most of them sessile, though a few are furnished with a long stalk, or tubular stem. They alternately contract and dilate them. selves.
ASCII, among geographers, an appellation given to those inhabitants of the earth, who, at certain seasons of the year have no shadow: such are all the inhabitants of the torrid zone, when the sun is vertical to them.
ASCIUM, in botany, a genus of the Polyandria Monogynia class and order. Character: calyx five-leaved; petals five; berry four-celled, with two seeds in each. One species in Guiana, a tree 80 feet high.
ASCLEPIAS, swallow-wort, in botany, a genus of the Pentandria Digynia class of plants, the calyx of which is a permanent perianthium, divided into five acute and small segments; the corolla consists of a single petal, divided into five deep segments at the mouth; and its fruit consists of two follicles or vaginae, containing a great number of imbricated seeds, winged with downThere are about 40 species. The swallow.
worts are either shrubs or tall upright perennial herbaceous plants, milky and poisonous, or at least acrid. The fiowers are borne on solitary peduncles, several together in umbels, and surrounded with a manyleaved involucre. They are very singular in their structure. Flies in searching for the honey in the nectary are frequently caught by the legs, and are not able to extricate themselves. A. syriaca is a native of North America, where the tender shoots are eaten as we eat asparagus. The flowers are so odoriferous as to make it very agreeable to travel in the woods, especially in the evening. They nake a sugar of them in Canada, gathering them in the morning, when they are covered with dew. Poor people collect the cotton from the pods, and fill their beds with it. ASCOBOLUS, a genus of the Cryptogamia Fungi. Fungus semi-spherical, containing oblong vesicles, somewhat immersed in its disk, which eject the seeds with an elastic force. ASCOPHORA, a genus of the Cryptogamia Fungi. Fungus erect, on a setaceous stalk; head globular-oblong; inflated, opake, elastic, bearing the seeds externally. There are seven species, and two divisions. A. clustered on a common receptacle. B. detached. ASCYRUM, in botany, a genus of plants with a rosaceous flower, and an oblong capsular fruit, formed of two valves, and containing a number of small, roundish seeds. It belongs to the Polyadelphia Polyandria class of Linnaeus, and is so nearly allied to the Hypericum, that Tournefort makes it the same genus; from which, however, it is distinguished by having only four petals, whereas the hypericum has five. ASH, in botany. See FRAxinus. ASILUS, in natural history, a genus of insects of the order Diptera. Essential character: mouth with a straight, horny, bivalve snout. The most common European species of asilus is the A. crabroniformis, a moderately large insect, nearly equalling a hornet in length, but of a much more slender and sharpened form: the head and thorax are of a ferruginous colour: the eyes black: the upper half of the abdomen velvet black;
the lower half bright orange colour; the
whole having a bright silky or downy surface: the wings are a dull yellow brown, and marked on their inner edge by several dusky triangular dashes of spots. Though of a somewhat formidable aspect, this insect is incapable of piercing with any degree of
severity. It preys on the smaller kind of insects, and proceeds from a smooth, white, subterraneous larva, of lengthened shape, and destitute of legs: the pupa resembles that of the tipula. There are several other species. . t ASPALATHUS, aspalath, in botany, a genus of the Diadelphia Decandria class of plants, the calyx of which consists of a singleleased perianthium, divided into five segments: the corolla is papilionaceous; the fruit is a roundish, turgid, unilocular, bivalve pod; the seed is single, and frequently kidney-shaped. According to Martyn there are 37 species; but Gmelin has enumerated nearly double that number. The plants of this genus, with few exceptions, are natives of the Cape of Good Hope. They are shrubby, or at least under-shrubs. The leaves are simple: the flowers mostly yellow. They may be propagated here by seeds brought from the Cape. ASPARAGIN, a name given to a lately discovered juice of asparagus, which was discovered by expression and evaporation. Various crystals gradually make their appearance, and among others crystals of asparagin easily separated from the rest on account of their colour and figure. The crystals are white and transparent, and have the figure of rhomboidal prisms: it is hard and brittle, and its taste is cool and slightly nauseous, so as to occasion a secretion of saliva. It dissolves in hot water, but not in alcohol. The aqueous solution does not af. fect vegetable blues. Neither infusion of galls, acetate of lead, oxalate of ammonia, muriate of barytes, nor the hydro-sulphurat, occasion any change in it. When triturated with potash no ammonia is disengaged. When heated it smells, and emits penetrating vapours, affecting the eyes and nose like the smoke of wood. Nitric acid dissolves it with the evolution of nitrous gas. These properties distinguish it from all other vegetable substances. ASPARAGUS, in botany. Class, Hex-, andria Monogynia. Gen. char. cal. none; cor. petals, six, cohering by the claws, oblong, erected into a tube, three alternately interior, permanent; stam. filaments six, filiform, inserted into the petals, erect, shorter than the corolla; anthers roundish; pist. germ. turbinate, three-cornered; style very short; stigma a prominent point; perberry globular, umbilicated with a point, three-celled; seeds two, round, angular on the inside, smooth. As PARAGUs, in gardening, comprehends