O P A 
is a fed, it is ground to powder,'and the infuiion of it in 
water is by the tanners termed ooze. Woodland Companion. 
To COZE, t’. n. To flow by ftealth ; to run gently; to 
drain away.—A wat’rifli humour fweii’d and ooz'd agen. 
Drydcn. 
The lily drinks 
The latent rill, fcarce oozing through the grafs. Thomfon. 
OO'ZY, adj. Miry ; muddy ; (limy.—The oozy places 
and holes, which, it mud be fuppofed, the fea left behind 
it. Lefile's Short Math. with the Drifts. 
Front his oozy bed 
Old father Thames advanc’d his reverend head. Pope. 
To OPA'CATE, v. a. [oprico, Lat.] To (hade ; to cloud ; 
to darken ; to obfcure.—The fame corpufcles upon the 
unftopping of the glafs, did opucate that part of the air 
they moved in. Boyle. 
OPA'CITY , f. [opncite, Fr. opaeitas, Lat.] Cloudinefs; 
want of tranfparency.— Can any tiling eicape eyes in 
whofe opticks there is no opacity? Brown.- — Had there not 
been any night, (liadow, or opacity , we (hould never have 
had any determinate conceit of darknefs. Glanville. —How 
much any body hath of colour, fo much hath it of opacity, 
and by fo much the more unfit is it to tranfmit the Ipecies. 
Bay on the Creation. —The lead parts of almoft all bodies, 
are in fome meafure tranfparent; and the opacity of thofe 
bodies arifeth from the multitude of reflexions caufed in 
their internal parts. Newton. 
OPA'COUS, adj. [oprecHS, Lat.] Dark; obfcure; not 
tranfparent.—When he perceives that opacous bodies do 
not hinder the eye from judging light to have an equal 
diffufion through the whole place that it irradiates, he can 
have no difficulty to allow air, that is diaphanous, and 
more fnbtile far than they, and, confequently, divilible 
into leffer atoms; and, having letter pores, give^ lefs fcope 
to our eyes to mifs light. Dighy. 
Upon the firm upacovs globe 
Of this round world, whofe firft convex divides 
The luminous inferior orbs, inclos’d 
From chaos, and the inroad of darknefs old, 
Satan alighted. Milton's P. L. 
OPA'COUSNESS, f. The (fate of being opaque.—Myf- 
teries, which (without thefe coverings) even the opacouf- 
nefs of the place were not obfcure enough to conceal. 
Evelyn. 
O'PAL, / [SeeOPALus.] A very elegant and Angular 
kind of (cone, from the head of a pin to the bignefs of a 
walnut. It is naturally bright, and (hows all its beauty 
without the help of the lapidary : in colour it refembles 
the fined mother-of-pearl; but with a property of reflect¬ 
ing all the colours of the rainbow, as turned differently to 
the light. Hill’s Mat. Med.- —We have this done from 
Germany, and is the fame with the opal of the ancients. 
Woodward on Fofji/s. 
The empyreal heaven, extended wide 
In circuit, undetermin’d fquare or round ; 
With opal towers, and battlements adorn’d 
Of living faphir. Milton's P. L. 
OPA'LIA, f. Feafls celebrated at Rome in honour of 
the goddefs Ops. 
Varro fays, that they were held three days after the ex¬ 
piration of the Saturnalia ; according to Macrobius, they 
were held on the nineteenth of December, which was one 
of the days of the Saturnalia. He adds, that thofe two 
feafls were celebrated in the fame month, becaufe Saturn 
and Ops were hufband and wife ; and that it is to them 
we owe the invention of corn and fruits ; for which reafon, 
the fead was not held till the harveft and fruit-time were 
entirely over. The fame author obferves, that the vows 
offered to the goddefs were made fitting on the ground ; 
to (how, that (he was .earth, the mother of all things. 
OPALIN'KA, a town of the duchy of Warfavv : two 
miles weft of Pofen. 
Vgl. XVII. No. 1193. . 
O P A 505 
O'PALUS , f. Opal; in mineralogy, a precious done, 
ranking as a genus of the argillaceous clafs of earths. 
Generic characters—Confiding of alumine, the greater 
proportion of (ilex, with a little oxyd of iron, and gene¬ 
rally fome carbonat of magnefia and of lime; hardifli, 
fhining, hardly ever opaque, of a conchoidal texture, 
light, breaking into indeterminate fragments, parafitical, 
generally of a common form, ealily cracking into clefts ; 
melting with the greateft difficulty. 
When not opaque, there is a difpofition in this fub- 
ftance to refradt the rays of light in a very remarkable 
manner; the colour moft in efteem, as arifing from this 
refraCfion, is green. The effeCt is produced in confe- 
quence of the prefence of numerous fmall f ra6tu res or 
fiflures in the interior of the opal, the intervals of which 
produce a varying refraCfion of the rays of light. All 
thefe colours diiappear when the fubftance of the opal is 
reduced by mechanical means to very minute particles. 
There are (even Ipecies. 
1. Opalus hydrophanus, or hydrophanous opal : fome- 
wliat opaque, becoming tranfparent and changing its co¬ 
lour in liquids, adhering to the tongue. Found in the 
Feroe iflands, Iceland, Britanny, Hungary, Silefia, and 
Germany, generally accompanying other (tones of the 
genus, or in the ftate of incruftation, in contaft with 
chalcedony, prafe, chryfoprafe, ferpentine, granite, ne¬ 
phrite, jafper, porphyry, and indurated clay. Colour 
white, yellow, red, or green ; becomes gradually tranf¬ 
parent when foaked in water by imbibing the liquid ; and 
is fometimes, though rarely, found in the form of a tliree- 
fided pyramid. Contains (ilex 93, alumine 1 or 2, water, 
inflammable matter, and air, 5, with fometimes a little iron. 
2. Ophalus piceus, or pitch-ftone: of a waxy luftre, 
and imperfedtly-conchoidal texture. Found in amor¬ 
phous malfes of various lize, in France, Germany, Saxony, 
and various parts of Europe, and in New Spain. Colour 
greyilh-black, greeniih-brown, bluifh-grey, leek or olive 
green, red, or yellowifh, tranfparent, femi-tranfparent, or 
opaque, frequently preienting large or fmall grained dif- 
tindt concretions ; luftre a little greafy. 
3. Opalus ligneus, or wood-opal: nearly opaque, break¬ 
ing longitudinally into fibrous fractures, fipontaneoufly 
falling into crultofe fragments. Found in Hungary, in 
large maffes, which have the form of wood, of a milk-red- 
dilli or yellowilh-white, brown, or hyacinth, colour; has 
a fliining furface, and is generally femi-tranfparent on the 
edges ; fradture, when broken tranfverfely, conchoidal ; 
when broken longitudinally, exhibiting the texture of 
wood ; is very brittle, and confidered as fragments of 
wood impregnated with femi-opal. 
4. Opalus cereus, or wax-opal: femi-tranfparent, light 
yellow, of a perfedtly-conchoidal texture. Found in Po¬ 
land and Hungary, in rounded fragments, and often im¬ 
bedded in jafper and indurated clay; its colour is fome¬ 
times a waxen, fometimes a honey, yellow, frequently 
verging to brown ; it is brittle, (liining very much inter¬ 
nally, and breaks into acute, and often nearly difcoid, 
fragments. 
5. Opalus vilior, menilite, or femi-opal : hard, lightifli, 
eafily breaking into acute fragments. Found in Poland, 
Bohemia, Hungary, Auftria, Saxony, Germany, and Me- 
nil-le-Montant, near Paris, whence the name. Colour 
various fliades of white, grey, yellow, red, brown, often 
mixed together; diaphanous or opaque, rarely tranfpa¬ 
rent; texture more or lefs perfedtly-conchaceous, and its 
luftre more or lefs glally ; is very brittle, and fometimes 
adheres to the tongue. Specific gravity, 2’ 185. 
6. Opalus vulgaris, or common opal: refledting a diffe¬ 
rent colour according to its polition as to light, hardifli, 
lightifli, diaphanous, breaking info rather-obtufe frag¬ 
ments. Found in Poland, Silefia, Saxony, Hungary, and 
Germany, ufually imbedded in other (tones of a common 
form, rarely kidney-form or botryoidal, fhining a little 
internally, generally fub-opaque. Colour white, yellow, 
red, green of various mixtures ; fometimes it is found in- 
6 N cioflng 
