Page:Cyclopaedia, Chambers - Volume 1.djvu/636

 EBU

i 270 ]

ECC

of Sri Mam-ice, belonging to the Hutch, likewife furniflies Part of the Ebonies ufed in Europe.

Authors; and Travellers, give very different Accounts of the Tree that yields the black Ebony : By fome of their Defcriprions it fhould be a Sort of Palm Tree, by others a Cytifus, &c. The mod authentick of them, is that of Monf. Flacourt, who rcfided many Years in Madagascar as Governour thereof. He affures us that it grows very high, and big 5 its Bark black, and its Leaves rcfembling thole of our Myrtle, of a deep, dusky, green Colour.

Tavermer affures us, that the Wanders take Care to bury .their Trees, when cut down, to make them the blacker. F. Plumier mentions another black Ebony Tree, difcovered by him at St. 'Domingo, which he calls Spartium portulacce foliis aculeatum Ebeni rnaterice. Candia alfo bears a little Shrub, known to the Botanifls, under the Name of Ebemis Cretica.

'Pliny and Diafcorides fay, the beft Ebony comes from Ethiopia, and the worft from India 5 but 'Eheophraftus prefers that of India. Slack Ebony is much prefcrr'd to the other Colours. The beft is a jet black, free ot Veins and Rind, very maffive, ailringent, and of a lharp pungent Tafte.

Its Rind infiifcd in Water, is faid to purge pituita, and cure Venereal Diforders 5 whence Matthiolus took Guaiacum for a Sort ol Ebony. It yields an agreeable Perfume, when laid on the Coals : When green, it readily takes Fire, from the Abundance of its Fat. If rubbed againft a Stone, it becomes brown. The Indians make Statues of their Gods, and Scepters for their Princes, of this Wood. It was firil brought to Rome by Pompey, after his fubduing Mithri- dates. J Tis now much lefs ufed among us, than antiently 5 fince the Difcovery of fo many Ways ot giving other hard Woods a black Colour. See Marquetry.

As to green Ebony, belides Madagafcar, and St. Maurice, It likewife grows in the Antilles, and efpecially in the Iile of fobago. The Tree that yields it is very bulhy, its Leaves ilnooth, and of a fine green Colour. Beneath its Bark is a white Rind about two Inches thick 5 all beneath which, to the very Heart, is a deep green, approaching towards a black 5 tho', fomctimes, ftreak'd with yellow Veins. Its Ufe -is not confined to Mofaic Work : 'Tis like- wife good in dying, as yielding a fine green Tincture.

As to red Ebony, called alfo Grenadilla, we know little of it more than the Name.

The Cabinet-Makcrs, Inlayers, £5V. make Pear free, and other Woods, pafs for Ebony, by Ebomjing, or giving it the black Colour thereof. This, fome do, by a few Waftics of a hot Decocfion of Galls, and when dry, adding Writing Ink thereon, and poliihing it with a ftitf firufh, and a little hot Wax.

Others heat, or burn their Wood black.

EBRBUHARITES, a Sect, or Order of Religious among the Mahometans; thus call'd from their Founder Ebr- liihard, a Difciple of Nacfchi bendi.

The Ebrbuharites, notwithllanding the extraordinary Sanctity they make Profeflion of, witn an abfoiute Dere- liction of all worldly Things, are regarded by the Mujfel- ntans, as no better than Hereticks; by Realbn they don't elleem themfelves obliged to go in Pilgrimage to Mecca. To excufe themfelves herefrom, they urge tnat the Pure- nefs of their Souls, their fublime Contemplations, Extafies, iSc. ftiew them Mecca and Mahomet's Tomb, witnout ifirring out of their Cells.

EBULLITION, in Phyficks, the Aft of Soiling; or, a vehement Agitation of the Parts of a Fluid, produced by pirc. See Boiling.

Philofophers are difagreed about the Caufe and Manner of Ebullition. Some account for it from an Attenuation of the Particles of the Fluid, at the Bottom of the Veffel; which, by being attenuated, become lighter, and heave up- wards againft the fuper-incumbent Load : Others, from the Particles of Fire mixing with, and dilating the Par- ticles of the Fluid, and fo rendering them fpecifically lighter : And others, not from any Attenuation, nor even Rarefaflion of the Particles of the Fluid by the Action of Heat; but from a Rarefaction of the Air pent up, and intermix'd with the Fluid; which coming to expand, tends upwards againft the Preffure of the left heated, lefs rarified Part of the Fluid. See Heat, Air, iSc.

A more precife Account of the Procefs under the forc- [aid Article Boiling.

Ebullition, in Chymiftry, F£ c. is alfo ufed for a violent interline Motion, or Colluaation of Parts, occafion'd by the Mixture of Salts of different Natures.

Dr. Harris will have it properly, and immediately, to fignifie that particular Struggle, or Eftcrvefcence, arifing upon the mingling together of an acid and alcalifate Liquor. See Acid and Alcali.

Mr. Soyle has an Experiment to fhew, that a confide- rable Ebullition may be produced by fuch a Mixture, without the Bodies acquiring any Heat 5 nay, that a Degree

of Cold may be produced greater than was in either of the Bodies fingly; tho accompanied with a great Strudale Tumult, Noife and Froth. For having Ihook one Pari of Oil of Vitriol, into 12 Parts of common Water, the Mixfmv. was at firft fenfibly warm : Then, the Ball of a Th-rmo meter was placed in it, till the included Spirit had gainM the Temperament of the Mixture; but then a conven : ent Quantity of Volatile Salt of Sal Armoniac, being gradually nut in to fatiate the acid Spirits of the Mixture, the Spirit in the Thermometer defcended above an Inch. See Ef- fervescence.

ECARTELE, in Heraldry. Sec Quarterly.

E.CCANTHIS, or ECKANTIS, in Medicine, is a Dif- eafe of the Eyes.

The Eccanthis, or Eckantis, is properly a fle/hy Ex- crefcence, in the Canthus, or Angle of the Eye; thus call'd from the Greek, °.yy&ti<, which fignifies the fame Thing.

ECCE-Homo, among Painters, a Name given a Painting, wherein our Saviour is reprefented in a Purple Robe, with a Crown on his Head, and a Reed in his Hand; fuch as he was prefented betore Pilate by the Jews.

The Phrafe is Latin, borrow'd from the Words of the Jews themfelves, q. d. fhis is the Man.

He has a fine Ecce homo.

ECCENTRIC, or EXCENTRICK, in Geometry, is ap- plied where two Circles, or Spheres, tho' comain'd, in fome Mealure, within each other, yet have not the fame Centre; and confequentfy are not parallel : In Oppofition to Con- centric; where they are parallel, have one and the fame common Centre. See Concentric.

The Sun's Orbit is Eccentric, with regard to the Globe of our Earth; Mars is very Eccentric, with regard to the Sun, that is, his Motion is about a very different Centre. See Earth, &c.

Eccentric, in the New Aftronomy, or Eccentric Circle, is a Circle, asPDAE, (Tab.Afrroiioin.Fig.it.) defcribed from the Centre of the Orbit of a Planet C, with half the Axis C E, as a Radius. See Eccentricity.

Eccentric, or Eccentric Circle, in the Antient Ptole- maic Aftronomy, was the very Orbit of the Planet it felf, which it was fuppofed to decribe about the Earth; and which was conceiv'd Eccentric thereto; called alfo the 'Deferent. See Deferent.

In Lieu of Eccentric Circles round the Earth; the Mo- derns make the Planets defcribe Elliptic Orbits round the Sun; which accounts for all the Irregularities of tie Mo- tions of the Planets, and their different Di fiances from the Earth, &c. more juftly and naturally. See Orbit. -

Anomaly of the Eccentric, is an Arch of the Eccentric Circle as AK, intercepted between the Aphelion A, ' and the right Line K L, which paffuig thro' the Centre of the Planet K, is drawn perpendicularly to the Line of the Apfides A P. See Anomoly.

Eccentric Equation, in the Old Aftrornony, is an Angle made by a Line drawn from the Centre of the Earth, with another drawn from the Centre of the Eccentric, to the Body or Place of any Planet; the fame with the Profiaphierefis; and is equal to the Difference, (accounted in an Arch of the Ecliptic) between the Sun's, or a Planet's, real, and apparent Place. See Prostafhjeresis.

Eccentric Place of a Planet, in its Orbit, is the Place wherein the Planet is fcen from the Sun. See Place.

Eccentric Place, in the Ecliptic, is the Point of the Ecliptic, to which the Planet viewed from \the Sun, is re- ferr'd. This coincides with the Heliocentric Place. Sec Heliocentric.

ECCENTRICITY, the Diftance between the Centres of two Circles, or Spheres, which have not rhe fame Centre. See Eccentric.

Eccentricity, in the old Aftronomy, is the Diftance of the Centre of the Orbit of a Planet, from the Centre of the Earth. See Planet.

That the five Planets have fuch an Eccentricity, is al- low'd on all Sides, and may be evinced from feveral Con- fiderations; chiefly this, that Saturn, Jupiter, Mars, Venus and Mercury, at fometimes appear greater, ' and at others lefs; which can only proceed from hence, that their Orbits being Eccentric to the Earth, in fome Parts thereof they are nearer us, and in others more remote : But as to the Eccentricities of the Sun and Moon, fome Difpute has been made.

The Moderns many of them hold, that the Sun and Moon appear fometimes larger, and fometimes lefs; not that they are nearer us at one Time than another, but becaufe they are view'd through different Columns of Air, which producing a Difference in the Refraction of then- Light, may occafion thofe different Appearances. Accord- ingly, we find very fudden Afterations of the apparent Magnitude of the Moon; where nothing but a Change in the Air .can take Place. See Moon and Sun.

Thus