188

A PIT

APIl

with thunder in his hand ; and such relief was produced by thechiaroscuro in this piece, that the fingers seemed to shoot forward,and the thunder-bolt to be out of the picture. IIis Venus Avn-was esteemed the most exquisite figure which the pencilcould create: it is therefore extolled by the It Oman poets, Pro-pertius and Ovid ; and the poet of Sidon, Antipater, has left aGreek epigram on it.

APENfi, a chariot,] in antiquity, a kind of chariot,

wherein the images of the gods were carried in procession on certaindays, attended with a solemn pomp, songs, hymns, dancings, &c.

APENNINUS, the Apennine , a mountain, or ridge of moun-tains, running through the middle of Italy - from X. W. to S. W.for 700 miles, in the form of a crescent: beginning at the Alps inLiguria , or the Riviera di Genoa; and terminating at the strait ofMessina, or at Reggio .

APENNIS, in ancient law's, a deed or instrument, made infavour of a person, who lias lost the title-d^eds to his house or landby fire.

APENZEL, a canton of Switzerland , having the town andabbey of St. Gall on the N. the county cf Toggenburgon the \V.the lordship of Sax in the canton of Zurich , and that of Gambs inthe canton of Schweiz , on the S. and the Rheinthall or Rhine-tailey, on the E.

Apenzei,, the capital of the canton, 25 miles S. of Constance.

APEPSY, Gi\] a loss of natural concoction.

APERIENTS, [from uperiens, opening, Lat] in the materiamedica, medicines that facilitate the circulation of the humours, byremoving obstructions. The live aperient roots oftheshopsare small-age, fennel, asparagus, parsley, and butcher’s broom. T he livelesser aperients are, madder, grass, eryngo, capers, and chammoc.

APERISTATION, [fromre, without, and 7riois-azif, unfavourablecircumstance,] in the ancient physic, denotes an ulcer of a mild,or benign kind, and not attended; w ith any severe symptom.

APERTIONS, in architecture, are the openings in a building;as doors, windows, stair-cases, chimneys, outlets and inlets forlight, smoke, &c. The apertions should be as few as may be;it being a rule, that all openings are weakenings; and they shouldnot approach too near the angles of the walls.

APERTIO Portarujm, [Lat.] in astrology, a great change inthe air, upon certain configurations.

APERTURE, [from aperio, (o open, Lat.] the opening ofany thing, or a hole or cleft in any continuous subject.

Aperture, in geometry, the space between two right lineswhich meet in a point, and’ form an angle.

Aperture, in optics, a round hole in a turned bit of wood orplate of tin, placed within side of a telescope or microscope, nearto the object-glass, by means of which more rays are admitted,and a more distinct appearance of the object is obtained. Accord-ing to Mr. Huygens , the best aperture for an object-glass of thirtyfeet, is as thirty to three; that is, as ten to one, so is the squareroot of the focal distance of any lens, multiplied by thirty to itsproper aperture. Mr. Auzout says, he found by experience,that the proper apertures of telescopes ought to be nearly in thesubduplicate ratio of their length. It is certain that object-glasseswill admit of greater apertures, if the tubes be blackened inside,and their passage be furnished with wooden rings.

Aperture, in hydraulics, the orifice in a vessel through whicha fluid flows. See Hydraulics.

APERTURES, or APERTIONS, in architecture. See Apkr-

■* TIONS.

APETAEOUS, [of « priv. and w<raXov, a leaf,] without petaiaor flower-leaves.

APEX, [Lat.] in antiquity, the crest of a helmet, but moreespecially a kind of cap worn by the fkrvmens.

Apex is used by grammarians, for a long accent or mark, todenote that a syllable is to be pronounced long.

APILERESIS, [repaioEcrij,] a figure in grammar, that takesaway a letter or syllable from the beginning of a word.

Afhjeresis, in medicine, denotes a necessary taking awav orremoval of something that is noxious. In surgery, it signifies anoperation whereby something superfluous is taken away.

APHASIA , [from re, andftyo, I speak,] in the sceptic philoso-phy, denotes a state of doubt, wherein a person not knowing whatto determine on, it is best for him to be silent.

APHELIA, [from nftAsr, simple,] in rhetoric, is used to denotesimplicity of diction.

APHELION, or APIiELIUM, "[from msch, from, and at thethe sun,] that part of the orbit of a planet, in which it is at tiiepoint further removed from the sun.

API! II.ANTIIROPY, [from re, neg. friend, and nyO:aino;,man,] among physicians, denotes the state or disorder, wherein aperson has an unnatural disrelish for mirth and society, and in-dulges solitude and melancholy.

APIilS, in zoology, the puceron, vine-fretter, or plant-louse;a genus of the class and order insecta hemiptera. Rostrum orbeak inflected; antenna.’or feelers longer than the thorax; wingsfour, erect, or they are wanting; feet of the ambulatory kind; bellyoften ends in two horn;, from which is ejected that most delicate juicecalled honeydew; which see. There are seventy-three species ofthe aphis, all of them inhabitants of particular plants, from whichtheir trivial names are taken ; as, aphis ribis, rosa’, ulmi, &c. inthe quality of the excrement voided by these insects, there issomething wonderfully extraordinary. Mr. Curtis collected someon a piece of writing-paper, from a brftod of (he apiiis salicis, andfound it to be sweet as sugar; and observes, that were it not forthe wasps, ants, flies, and other insects, that devour it as quicklyas it is produced, it might, no doubt, be collected in considerablequantities, and by the processes used with other saccharine juices,might be converted into the choicest Sugar or sugar-candy. Thesweetness of this excrementitious substance, the glossy appearanceit gave the leaves it fell upon, and the swarms of insects this matterattracts, led him to imagine the honey-dew of plants was no otherthan this secretion, which further observation lias since fully con-firmed ; and not, as its name implies, a sweet substance fallingfrom the atmosphere. On this opinion, it is further remarked]that it neither tails from the atmosphere, nor issues from the plantitself, as is easily demonstrated, if it fell from the atmosphere,it would cover every thing it fell upon indiscriminately, whereaswe never find it but on certain living plants and trees. We findit also on plants in stoves and green-houses covered with glass.If it exuded from the plant, it would appear on all the leaves ge-nerally and uniformly ; whereas its appearance is extremely irre-gular, not alike on any two leaves of the same tree or plant, somehaving none of it, and others being covered with it but partially.It is probable that there never exists any honey-dew but wherethere are aphides; though such often pass unnoticed, being hiddenon the underside of the leaf: and wherever honey-dew is observ-able upon a leaf, aphides will lie found on the underside of theleaf or leaves immediately above it, and under no other circum-stance whatever. If by accident any thing should intervene be-tween the aphides and tiie leaf next beneath them, there will lie nohoney-dew on that leaf: and thus lie conceives it is incontroverti-bly proved, that aphides are the true and only source of honey-dew. Of the British species of aphides, one of the largest andmost remarkable is tiie aphis salicis, which is found on tiie different,kinds of willows. When bruised, those insects stain tiie fingerswith red. Towards the end of September multitudes of the tull-grown insects of these species, both with and without wings, deserttiie willows on whicli they feed, and ramble over every neigh-bouring object in such numbers that we can handle nothing in theirvicinity without crushing some of them, while those in a younger,or less advanced slate, still remain in large masses upon the trees.Aphis ros* is very frequent, during tiie summer months, on tiieyoung shoots anil buds of roses; it is of a bright green colour :the males are furnished with large transparent w ings. A. vitis ismost destructive to vines; as A. ulmi is to tiie elm-tree. See PlateVII.

APHONIA, among physicians, signifies a suppression or totalloss of voire, it is deriveef from re, without, and tfwv, speech.

APHORISM, [reipojivfMf,] a maxim ; a precept contracted ina short sentence; ail unconnected position. It is chiefly used in*medicine and law.

API1ROD1S1A, in antiqnity, festivals in honour of (he god-dess Afsoh-rn, or Venus. There are several of these aplirodisiaobserved in divers parts of Greece ; tiie most remarkable w’as thatat Cyprus , first instituted by’ Cinyras, out of whose family certainpriests of Venus were elected, and for that reason named Kmpilai.

APIIRODISIUS, in chronology, denotes the eleventh monthin tiie Bithynian year, commencing on the 25th of July in ours.

AP1IROD1TA, in zoology, a genus of the class and ordervermes mollusca. Body creeping, oblong, covered with scales,and furnished with numerous bristly fasciculate feet on each side;

mouth