377 
O B S 
hath pleafed God to reftore them to health, been as wicked, 
perhaps worfe, as ever they were. Whole Duty of Man. — 
To regard or keep religioufly.—A night to be much ol- 
ferved unto the Lord, for bringing them'out of Egypt. 
'Ex. xii. 42.—To praftife ritually.—In the days of Enoch, 
people obferved not circumcifion or the fabbath. White. — 
To obey; tp follow. 
To OBSER'VE, v. n. To be attentive.— Obferving men 
may form many judgments by the rules of fimilitude and 
proportion, where caufes and eftefts are not entirely the 
fame. Watt.is Logich. — To make a remark.—I obferve, 
that when we have an aftion again ft any man, we muft, 
for all that, look upon him as our neighbour, and love him 
as ourfelves, paying him all-that juftice, peace, and cha¬ 
rity, which are due to all perfons. Kett/cwell. —Wherever 
I have found her notes to be wholly another’s, which is 
the cafe in feme hundreds, I have barely quoted the true 
proprietor, without obferving upon it. Pope's Letters. 
OBSER'VER, f. One who looks vigilantly on perfons 
and things; clofe remarker.—He is a great olferver. 
Shaliefpeare's Julius Coj'ar. 
Careful obfervers m ay foretel the hour, 
By lure prognoftics, when to dread a Ihow’r. Swift. 
One who looks on; the beholder.—Company, he thinks, 
leflens the lhame of vice, by lharing it; and therefore, if 
he cannot wholly avoid the eye of the olferver, he hopes to 
dill raft it at leaft by a multiplicity of objefts. South. 
If a flow-pac’d ftarhad ftol’n away, 
From the olferver's marking, he might ftay 
Three hundred years to fee’t again. Donne. 
One who keeps any law, or cuftom, or praftice.—Many 
nations are fuperftitious, and diligent obfervers of old cul- 
toms, which they receive by tradition from their parents, 
by recording of their bards and chronicles. Spenfer. —He 
was fo ftrift an olferver of his word, that no confideration 
whatever could.make him break it. Prior. — Himfelf often 
read ufefal difeourfes to his fervants on the Lord’s day, 
of which he was always a very ftridt and folemn olferver. 
Atterlury. 
OBSER'VIlilG, adj. Attentive ; watchful. AJh. 
OBSER'VINGLY, adv. Attentively; carefully : 
There is fome foul of goodnefs in things evil. 
Would men obfervingly diftil it out. Shahefpeare. 
To OBSESS', v. a. [obfdeo, ohfejfus, Lat.] To befiege ; 
to compafs about. Not in ufe. —The mind is olfejfed with 
inordinate glory. Sir T. E/yot's Gov.-— A man is faid to 
be olfejfed, when an evil fpirit followeth him, troubling 
him, and leeking opportunity to enter into him. Bullokar. 
OBSESS'ION, J'. [pbjeffio, Lat.] The aft of befieging.— 
The firft attack of Satan, antecedent to pofleftion.—Me¬ 
lancholy perfons are meft fubjeft to diabolical temptations 
and iilufions, and moft apt to entertain them ; and the 
devil beft able to work upon them ; but, whether by ob- 
feffion or pofleftion, I will not determine. Burton's Anat. 
of Melancholy. 
Grave fathers, he’s poftefs’d; again, I fay, 
Poflefs’d: nay, if there be pofleftion 
And objejfion, he has both. B. Jonfou's Fox. 
OBS'FELD. See Oebsfeld. 
OBSIDIA'NUS, f. Obsidian; in mineralogy, a genus 
of filiceous earth. The ancients called it China marble. 
It has alfo the name of Iceland agate ; and Hauy calls it 
Lave vitrgufe obfulienne. Certain writers have fuppofed 
the name Cbfidianus derived from fomebody o£ the name 
of Obfidius, who was the inventor of the ufe of it; but 
it feems only a falfe fpellingof the word opfunms, ctno tvs 
from feeing the images of things in it. 
Charafters—Luftre refplendent, vitreous ; frafture per¬ 
fectly conchoidal; fragments very fharp-edged. The moft 
common colour is perfeftly black, fometimes greenifh and 
grey i ft), bluilh-green, and fmoke-grey ; yellow and red, 
according to Humboldt 5 moft commonly opaque, but 
Vol. XVII. No. 1184. 
O B S 
fometimes tranflucent on the edges. It is hard and eaftly 
frangible. Spec. grav. a - 348. Before the blow-pipe it 
melts into an opaque porous glafs, of a greyifh-white co¬ 
lour. Conftituent parts: 
Bergman. 
Abilgaard. 
Defcotils. Drappier. 
Silex 
69 
7 + 
72-0 74-0 
Alumine 
22 
12 
12-5 140 
Oxyd of iron 
9 
14 
2 3'o 
Lime 
- • — 
— 
■- 12 
Potafti and foda 
— 
— 
IO'O 3-3 
Lois 
— 
— 
3'5 4'5 
100 
100 
IOO’O IOO'O 
This mineral 
is found 
in mattes', 
and fometimes in 
rounded pieces. It occurs in Iceland, in Siberia, in the 
Lipari-iflands, in Hungary, in Madagafcar, the ifland of 
Teneriffe, in Mexico, Peru, and fome of the South-Sea 
iflands. Humboldt difeovered a fpecies in New' Spain, 
which was chatoyant in a confiderable degree. The obfi- 
dian from Hungary is found in infulated pieces among 
detached malles of granite, gneifs, and decompofed por¬ 
phyry. Obfidian was long fuppofed to have a volcanic 
origin ; but it appears, from the accounts of thofe who 
have viflted Iceland, that it is not only found in the vici¬ 
nity of Hecla, but every-where diftributed like quartz 
and flint; and belides, it is not unfrequent in countries 
where volcanoes were never known to exift. 
The fine colour and hardnefs of this ftone, have brought 
it into ufe for ornamental purpofes. Among the ancient 
Mexicans and Peruvians it was employed for mirrors; and 
alfo for ciuting-inftruments ; as knives, and even razors. 
Hernandez law the Mexican cutlers make a hundred 
knives of obfidian in the courfe of an hour. Obfidian, it 
is faid, has alfo been ufed as mirrors for telefcopes. 
Mr. Salt, during his travels in Abyftlnia in the year 
1810, was able, by meeting with fome of this mineral, to 
fettle a difputed point in ancient geography. He alcer- 
tained the Bay of Howakil to be the fame with that which 
is mentioned in the Periplus of the Erythrrsan Sea, as ce¬ 
lebrated by the ancients for producing this ftone. Some 
conjeftures, as to their identity, had been formed by lord 
Valentia and Mr. Salt on their previous voyage to the Red 
Sea; but the faft is'now proved, as far as Inch a circum- 
ftance admits of proof, by Mr. Salt having aftually found, 
on the fpot, a quantity of the fpecific fubftance in quef- 
tion ; fpecimens of which he brought home. He has thus 
been doubly fortunate; not only in fettling a difputed 
point of ancient geography, but alfo in refeuing the au¬ 
thority of Pliny from the ridicule of Salmafius. Dr. Vin¬ 
cent, who fuggefted the great probability of eftefting the 
difeovery in the manner in which it is now accompliftied, 
but who, owing to the incorreftnefs of the charts, could 
fix on no fpot on the coaft agreeing with the defeription in 
the Periplus, muft no doubt have been highly gratified by 
this confirmation of his ideas. See Monthly Review' for 
Jan. 1815. 
OBSID'IONAL, adj. [Fr. obfulionalis, Lat.] Belong¬ 
ing to a fiege.—Their honorary crowns, triumphal, ovary, 
civical, objidionat, had little of flowers in them. Sir T. 
Brown's Mifcell. 
OBSIGILLA'TION, f. [from the Lat. ob, againft, and 
figillum, a feal.] The aft ot fealing-up. Cote. 
To OBSIG'NATE, v. a. [objigno, Lat.] To ratify ; to 
feal-up.—As circumcifion was a feal of the covenant made 
with Abraham and his pofterity, fo keeping the Sabbath 
did obfighate the covenant made with the children of 
Ifrael, after their delivery out of Egypt. Barrotv on the 
Decalogue. 
OBSIGNA'TION, f. Ratification by fealing ; aft of 
fixing a feal; confirmation.—As the fpirit of obfgnation 
was given to them under a feal, and within a veil; fo the 
fpirit of manifeftation or patefaftion was like the germ of 
a vine, or the bud of a rofe, plain indices and fignifications 
of life. Bp. Taylor's Sermon on Whitfunday. 
5 D OBSIG'NATORY, 
