Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/70

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preparation of the Phngitis lapis, which was the wetting and nightly calcining it, m'uft be very proper to make the vitriol contained in this appear and exert itfelf in the working with it. Galen, de Med. Simpl. L. 9. Sec alfo Mercat. Mcta- loth. Am. 9. c. 15. p. 240. AGGADA, in Jewifh antiquity, an ingenious tale, or ftory ; of which kind there are many in the Talmudt. There arc feveral books extant among the Jews under this title *. R. San-Ifrael Ben Juda has publifhed Novellas Agga- darum, or new explanations of the ftories and relations in the Talmud, difcovering the hidden meanings thereof b. — [« Vid. Wolf. Bibl. Hebr. b Aft. Erud. Lipf. 1685. p. 1. fcq.] AGGER, in antient Latin writers, denotes the middle part of a military road, raifed into a ridge, with a gentle flope on either fide, to make a drain for the water, and keep the way dry. Agger is alio ufed for the whole road, or military way. Du Cange, Glofl". Lat. T. 1. p. 107. fcq. Where high-ways were to be made in low grounds, as be- tween two hills, the Romans ufed to raife them above the adjacent land, fo as to make them of a level with the hills. Thcfc banks they calfed Aggeres. Bergicr_ mentions feveral in the Gallia Belgica, which were thus railed, ten, fifteen, or twenty feet above ground, and five or fix leagues long. V. Bergier, Hift. desChemins, 1. 2. Mem. of Liter. T. 7. p. 35.

They are fometimes alfo called Aggeres cakcati, and now ge- nerally known by the name chauffees, or caufeways. Agger alfo denotes a work of fortification, ufed both for the defence and the attack of towns, camps, &c. In which fenfe, Agger is the fame with what was otherwife called vallum", and in latter times aggejlum b, and among the moderns lines j fometimes cavaliers, terajjes, &c. — [» V. Horfiey, Britan. Rom. 1. 1. c. 8. p. 107. b Piiifc. Lex. Antiq.j

The Agger was ufually a bank, or elevation of earth, or other matter, bound and fupported with timber; having fometimes turrets on the top, wherein the workmen, engi- neers, and foldiery were placed. It was alfo accompanied with a ditch, which ferved as its chief defence. The ufual materials, of which it was made, were earth, boughs, fafcines, flakes, and even trunks of trees, ropes, &c. varioufly eroded, and interwoven fomewhat in the figure of ftars ; whence they were called Jlellati axes. Where thefe were wanting, ftones, bricks, tyles, fupplted the office : on fome occafions, arms, utenfils, pack-faddles, were thrown in to fill up. What is more, we read of Aggers formed of the carcafl'es of the (lain c ; fometimes of dead bones mixed with. lime d ; and even with the heads of flaughtered citizens e . For want of due binding, or folid materials, Aggers have fometimes tumbled down, with infinite mifchief to the men. — [ c Vakr. Max. 1. 7. c. 6. Jppian. de Bell. Civ. 1. 2. Flirt, de Bell. Hiipan. Jofeph. de Bell. Judaic. 1. 4. *> Span. Voy. P. 1. c Ducaf. Hift. Byzant. c. 17.] The befiegers ufed to carry on a work of this kind nearer and nearer towards the place, till, at length, they even reached the wall. The methods taken, on the other fide, to defeat them, were by fire, especially if the Agger were of wood ; by tapping and undermining, if of earth ; and, in fome cafes, by erecting a counter Agger. The height of the Agger was frequently equal to that of the wall of the place. Csefar tells us of one he made, which was thirty feet high, and three hundred and thirty feet broad. Befides the ufe of Aggers before towns, the generals ufed to fortify their camps with the fame ; for want of which precaution, divers armies have been furprized and ruined. There were vaft Aggers made in towns, and places on the fea-fide, fortified with towers, caftles, &c. Thofe made by Csefar and Pompey at Brundufium, arc famous f. Some- times Aggers were even built acrofs arms of the fea, lakes, and morafies ; as was done by Alexander before Tyre E, and by M. Antony and Caffius h. — [ f V. Cafar. de Bell. Civ. I. I. * jg. Curt. 1. 4. h Jppian. loc. cit.J The wall of Sevcrus, in the north of England, may be con- fidcred as a grand Agger, to which belong feveral lefTer ones. Beiides the principal Agger, or vallum, on the brink of the ditch, M. Horfiey describes another Agger on the fouth fide of the former, about five paces diftant from it, which he calls the fouth Agger ; and another larger Agger on the north fide of the ditch, called the north Agger. This latter he conjectures to have ferved as a military way ; the former, probably, was made for an inner defence, in cafe the enemy Ihould beat them from any part of the principal vallum, or to protect the foldiers againft any fudden attack from the pro- vincial Britains, Horjl. Brit. Rom. 1. 1. c. 8. p. 117. Agger Tarqumii, Tarquin's Agger, was a famous fence built by Tarquinius Superbus, on the eaft fide of Rome, to flop the incurfions of the Latins, and other enemies, whereby the city might be infefted. V. Pitifc. Lex. Ant. in voc. Agger is alfo ufed for the earth dug out of a trench and thrown up on the brink of it.

In which fenfe, the chevalier Folard thinks the word to be underfrood, when ufed in the plural number, fince we can

hardly fuppofe they would raife a number of cavalier?, or terrafles. V. Bibl. Raif. T. 5. p. 112.

Agger is alfo ufed for a bank, or wall, erected againft the fca, or fome great river, to confine or keep it within bounds. In which (enk, Agger amounts to the fame with what the antients called tumulus and moles ; the Dutch, dyke ; we, dam, fea-wall.

The firft hint of this kind of Aggers is faid to have been taken from fwallows, which (o flopped up one of the mouths of the Nile, with a vaft continued clufter of nefts, as to withftand all the weight and force of that river. We find a title in the code de Aggcribus Nili non rumpendis. Plin. Hift. Nat. T. 1. 1. 10. c. 33. p. 562. feq. Hoffm. Lex. Univ. T. r. p. 1C9.

Agger alfo denotes a heap of earth, raifed over the graves of the antients. Baxt. GlofT. p. 67. feq. Danet. Lex. Ant. in voc.

In which fenfe, it amounts to the fame with tumulus ; and is fometimes alfo called aggejlum. V. Hsjfm. Lex. Univ. T. 1. p 109. in voc. Aggejlum.

AGGLUTINATION [Cych)— Some affign a difference be- tween Agglutination and affimilation: in that fpecies of leop- rofy, called Aimmj, there is an adhefion, or Agglutination of the nutriment, but no affimilation. In the anafarcous dropfy, on the contrary, there is an adjunction, without any Agglu- tination ', i. e. there is an afflux of new matter, or nourifli- ment, but this fo thin and watery, that it wants the due ftiff- nefs and tenacity to make it bind. Gorr. Def. Med, p. 390. in voc. m-focripuG-j;, §htinc. Lex. Med. p. 12. Some will have Agglutination to be effected by a ferment ; others affert, that by reafon of the glutinous quality of the chyle, a mere contact fuffices to make it adhere to the parts. Nouv. Rep. Lett. T. 14. p. 1296.

Agglutination is ufed by fome aflxonomcrs to denote the meeting of two or more ftars in the fame part of the zodiac. Vital. Lex. Math. p. 15.

Agglutination is more peculiarly underftood of the feeming coalition of feveral ftars, fo as to form a nebulous ftar. See Nebulous, Cyct.

AGGREGATE (Cycl.) is particularly ufod by fome modern chemifts, and naturalifts, for a numerous collection of atoms, or minuteft corpufcles, whether homogeneous or heteroge- neous, joined together by contiguity, without regard to the quality of fuch atoms.

In which fenfe, Aggregate differs from text, as the former fuppofes no particular fituation, or pofition, of the corpufcles, other than what arifes from their proportion, and the rela- tion they bear to the ambient bodies, among whom the coa- lition is formed. See Text.

Aggregate alfo differs from mixt, as the latter is formed im- mediately out of the principles of matter, fo firmly united, as that it is very difficult, if not impoffible, to feparate them. Aggregate again differs from compound, as the latter is formed out of mixts, and is eafrly diffoh'able.

Aggregates then are the ultimate compounds, or the laft effects of compofition ; they refolve into compounds as their next ingredients, thefc into mixts, and mixts into fimplcs, or principles ; though, in ftrictnefs, Aggregates may refolve alfo into mixts, and mixts into fimples, inafmuch as they confift of heterogeneous parts.

This doctrine and diftinction of Aggregates, ?nixts, and com- pounds, is the foundation of the chemical theory of Beccher and Stahl ; which laft has traced it with great exactnefs. Hence has arifen a new doctrine of earths, metals, &c. Vid. Stabl, Diff. de Temperam, c. I. Eund. de Differ. M'txti, Texti, Aggregati, Indivldui, in Obferv. Halenf. T. 4. obf. 14. §. 21. p. 314. feq. It. Philof. Princip. Chemift. P. 1. §. 1. Sbaw, Not. ad Eund. p. 8 & 10. Cajl. Lex. Med. p. 24. Burggrav. Lex. Med. T. 1. p. 348.

AGIADES, a kind of Turkifh foldiery, employed in fortifying of camps, fmoothing of roads, and the like offices. Meurf. GlofT. p. 7. Du Cange, GlofT. Gr. T. 1. p. 10. Aquin. Lex. Milit. T. 1. p. 31.

AGIASMA, among antient writers, is fometimes ufed for the whole church, fometimes for the more facred part, or Bema, wherein mafs was faid, Du Cange, GlofT. Graec. T. 1. p. 10. feq.

AGILENSZ, in botany, a name ufed, by fome, for the com- mon hazel. Ger. Emac. Ind. 2.

AGILITY {Cycl.)— Some define Jgility, the art or habit of directing our ftrength, i. e. of intending, or remitting it to advantage. Place. AccefT. Ethic, c. 3. §. 24. feq. Mifc. Lipf. T. 1. p. 277.

The improving of Agility was one of the chief objects of the inftitution of games and exercifes. The Athletse made par- ticular profeffion of the fcience of cultivating and improving Agility. V. Mem. Acad. Infcript, T. 4. p. 441. Agility of body is often fuppofed peculiar to fome people ; yet it feems not owing to any thing in their frame and ftructure different from Gthers, but entirely to practice. Our travel- lers are ufually furprized at the great Agility of the natives of Malabar ; but Baldzeus takes off the wonder, by telling us, that all the gentry, and all the military people there, are bred in a manner to render this eafy to them - t and, from the age

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