Page 41

AET
AErometry includes the Laws of the Motion, Gra~ita.
tion, Preflion, Elaflicity, Rarefadion, Condenfation, &)c. of
that Fluid. See ELASTICITY, RAREFACTION, SC.
The Word Aerometry is but little ufed: In lieu hereof
we commonly call this Branch of Philofophy, Pneumatic&.
See PNEUMATICS.
' C. Wotfus, Profeffor of Mathematicks at Hall, having
reduced many of the Afeltions of this Fluid to geometrical
Demonfiration; published Elements of Aerometry, at Leip-
ftc, 1709, firfm in High fDutck and afterwards in Latin.-
Thus is the Docfrine of the Air incorporated into the Ma-
tbematical Sciences. See MATHEMATICKS.
The Word is compounded of Atd, and ,ASTpev, to meafare.
iERUGO. See RUST.
£ERUGO ./Eris, in Medicine, &C. See VERDEGREASE.
AERY, or AIRY, of Hawks, is what we call a Nell in
other Birds., See HAWK, and HAAWxING.
.JESCHYNOMENOUS Plants, among Botanifls, are
thofe popularly called Sen/itive Plants. See SENSITIVE.
.)ESNECY, in Law. See ESNECY.
.ESTIMATIO Capitis, in our antient Law-Books. See
WERE, WERELADE, WEREGILD, WC.
King dthe~flan, in a great Affembly held at Exeteri de,
dared what Mulfts were to be paid pro aeflimatione capitis,
for Offences committed againit feveral Perfons according to
their degrees; the Ejfimation of the King's Head to be
.opco 7'brymf&e; of an Archbifhop, or Satrapa, or Prince,
I5OOO ; of a Bilhop or a Senator, 8ooo; of a Priefi, or a
Thane, 2000, SC.   Crelfy's Church Hill. fol. 834. b. and
L, Hen. I.
iESTIVAL, or ESTIVNAT.. nf or eplon";nff t
See SUMMER,.         .a    .V    V};II;.      UI~tr
Thus, we fay, the aEftival So~l~ice, &c. in oppofition to
2lrumal. See SOLSTICE.
ESTUARY, ESTUARIUMj in Geography, an Arm of
the Sea; running up a good way into the Land. See SEA.
Such, is !BriJfol Channel, many of the Firths of Scot-
iadd, &c.
.EASTUARY, is Sometimes alfo ufed in Pharmacy, for a Va-
pour-Bath, Balneum Vaporofuem, See VAPOUR, and BATH.
ES Uftum, called alfo Crocus Veneris, a Chymical Pre-
paration, made of Copper cut into thin Plates, put into a
Crucible with Sulphur and Salt, firatumfuiper Jiratum, and
thus fet in a hot Charcoal Fire, till the Sulphur be con-
fumed. See CROCUS, COPPER, VENUS, SC.
It is very deterfive; and is ufed for eating oPF dead Flefh.
They who make this ufe of it, are to heat it red hot in the
Fire nine times; and quench it as often in Linfeed Oil. See
EPULOTIC.
.ETHER, is ufually underflood of a thin, fubtile Matter,
or Medium, much finer and rarer than Air; which com-
mencing from the Limits of our Atmofphere, poffeffes the
whole heavenly Space. See HEAVEN, WORLD, WC.
The Word is Greek, ri^ne, fuppofed to be form'd from
the Verb w9ei', to burn, to flame; fome Of the Antients, par-
ticularly Anaxagoras, fuppofing it of the Nature of Fire.
See FIRE.
The Philofophers cannot conceive that the largeft Part of
the Creation Should be perfectly void; and therefore fill it
with a Species of Matter under the Denomination of ,Ether.
-But they vary extremely as to the Nature and Characters
of this Ether.
Some conceive it as a Body Jui generis, appointed only
to fill up the Vacuities between the heavenly Bodies; and
therefore confined to the Regions above our Atmofphere.-
Others fuppofe it of fo fubtile and penetrating a Nature, as
to pervade the Air, and other Bodies; and poffefs the Pores
and Intervals thereof-Others deny the Exiflence of any
fuch fpecifick Matter; and think the Air it felf, by that im-
ienfeTenuity and Expanfion it is found capable of, may
difufe it felf thro' the interfiellar Spaces, and be the only
Matter found therein. See AIR.
In effiec, AEther, being no Objed of our Senfe, but the
mere Work of Imagination, brought only upon the Stage
for the fake of Hypothefis, or to folve fome Phlnomenon,
real or imaginary , Authors take the Liberty to modify it
how they pleafe.-Some fuppofe it of an. elementary Na-
ture, like other Bodies, and only diffinguifh'd by its Tenuity,
and the other Affehions confequent thereon: which is the
Philofophicat AEther.-Others will have it of another Spe-
cies, and not Elementary; but rather a fort of fifth Element,
of a purer, more refined, and Spirituous Nature than the
Subflances about our Earth; and: void of the common Af-
fedtions thereof, as Gravity, Wc.  The heavenly Spaces,
berng the fuppofed Region or Refidence of a more exalted
Clafs of Beings; the Medium mull be more exalted in pro-
vportion.-Such is the anrient and popular Idea of Ether, or
Itl7ereal Matter. See 'ETHEREAL.
The Term Ether being thus embarrafs'd with a Variety
of Ideas, and arbitrarily applied to fo many different things;
the later and feverer Philofophers chute to fet it afide: and
in lieu thereof, fublfitute other more determinate ones.
~At)                      AE T
Thus, the car-teiaas ufe the Terni AVateri Sibtliis;
which is their A-ther: And Sir I. Newton, fomermes, a
Subtile Spirit, as in the Clofe of his Principia. and fome-
times a Subtile or Athereal Medium; as in his Opticks.
The Truth is, there are abundance of Confiderations,
which feemn to evince the Exiflence of fome Matter in the
Air, much finer than the Air it felf.-There is an unknowns
Something, which remains behind when the Air is taken
away ; as appears from certain Effeds which we fee produ-
ced in Vacuo.-Heat, Sir I. Newton obferves, is communi-
cated thro' a Vacuum, almofi as readily as thro' Air: But
fuch Communication cannot be without fome interjacent Bo-
dy, to ac as a Medium. And fuch Body mufl be fubtile
enough to penetrate the Pores of Glafs; and may be very
well concluded to permeate thofe of all other Bodies; and
confequently be diffufed thro' all the Parts of Space: Which
anfwers to the full Character of an Ather. See HEAT.
The Exiflence of fuch Arthereal Medium being fettled;
that Author proceeds to its Properties ; inferring it to be not
only rarer and more fluid than Air, but exceedingly more
claffick, and adfive: In Virtue of which Properties, hQ
fhews, that a great part of the Phxnomena of Nature may
be produced by it.-To the Weight, e. g. of this Medium,
he attributes Gravitation, or the Weight of all other Bo-
dies; and to its Elaflicity, the elaffick Force of the Airj
and of nerv'ous Fibres, and the Emifflion, Refraaion, Reflec-
tion, and other Phanomena of Light; as alfo, Senfation,
Mufcular Motion, _cc.-In fine, this fame Matter feems the
Primum Mobile, the fir& Source or Spring of phyfical Ac-
tion in the modern Syffem.-See further tnder the Article
Subtile MEDIUM, ATTRACTION, GRAVITATION, REFRAC-
TION, REFLECTION, Wc. fee alfo FIBRE, Mufcular Mo-
TION, _ic. fee alfo NEWTONIAN Philofophy, &c.
The Carte/ian ,Ether is fuppofed not only to pervade,
but adequately to fill all the Vacuities of Bodies ; and thus
to make an abfolute Plenum in, the Univerfe. See Materia
SUBTILIS ; fee alfo PLENUM ;fee alfoCARTEsIANIsM, c.
But Sir I. Newton overturns this Opinion, from divers
Confiderations; by fhewing, that the Celeffial Spaces are'
void of all fenfible Refiflance: For, hence it follows, that
the Matter contained therein, mufl be immenfely rare, in
regard the Refiflance of Bodies is chiefly as their Denfity ;
fo that if the Heavens were thus adequately fill'd with a
Medium or Matter how fubtile foever, they would refifl the
Motion of the Planets and Comets much more than Quick-
filver, or Gold. See RESISTANCE, VACUUM, PLANET,
COMET, SC.
ETHEREAL, .IYTHEREUS, fomerthing that belongs to
lAther, or is of the Nature of Anther. See JTHlER.
Thus, we fay, the -thereal Space; A.thereal Regions,
Wc.-Some of the Antients divided the Univerfe, with re-
fpea to the Matter contain'd therein, into Elementary and
Athereal. See UNIVERSE, and ELEMENTARY.-      -Under
.,Ether, or the Ethereal World, was included all that Space
above the upper Element, viz. Fire. This they fuppofed
to be perfecly, homogeneous, incorruptible, unchangeable,
Wc. See CORRUPTION, WC.
'Twas a Point controverted among 'em, Whether or no
the }Ethereal Matter had the Property of Gravity ?-
Many late Philofophers, not only at home but abroad, con-
tend for its Gravity ; and even for its being the Caufe of
Gravity in all other Bodies.-In effed, fays Chauvin, Bo-
dies do not defcend by any inherent Principle, but by the
Impulfe or Trufion of Something external : which can be
nothing but .Ether ; in regard they fall in Facuo as readily,
nay more fo, than in open Air: From the fame Principle
arifes the Cohefion of Bodies, W!c. Lexic. Philofoqh. Foc.
,Ether. See MEDIUM.
.ETHEREAL Oil, is a fine, fubtile Oil, approaching nearly
to the Nature of a Spirit. See OIL.
Thus, the pure Liquor rifing next after the Spirit, in the
Disfillation of Turpentine, is called the -Ethereal Oil of Tur.
pentine. See TURPENTINE.
Some Chymiffs diflinguilh two Principles in Urine ; the
one a volatile urinous Salt, refembling Spirit of Nitre ; the
other an -Ethereal Oil, or Sulphur; partaking of the Na-
ture of Spirit of Wine. fDionis. See URINE.
.ETHEREAL Heaven. See Aethereal HEAVEN
JtETHIOPS Mineral, a Preparation of Mercury, made by
grinding equal Quantities of crude Quickfilver and Flower of
Sulphur, in a Stone or Iron Mortar ; till they become incor-
porated into a black Pouder. See MERCURY.
It is prefcribed for the Worms, and all Crudities and Acri-
mony of the Humours; and is reputed infallible againfi the
Itch, and other cutaneous Difeafes.
AETIANS, AETIANI, in Antiquity, a Se& or Branch bf
Arians, the Difciples of Aetius of Antioch, firnamed the
Impious ; who, according to Philafirins, was firfi Smith,
then Sophiff, and lafily Phyfician. See ARIIAN.
The Aetians had divers other Denominations ; as, TPu,'e
Arians, Etnomians, Heteroutians, 2'reglodytes,  See Eu-
NOMIANS, HETEROUSIAN, WC.
M                   JETIO-