484 O N A 
benefit of the predi&ion. This is plain from the LXX, 
(Exod. i. it.) where the words “ On, which is the city 
of the fun,” are interpolated, in order to fupport the 
pretenfions of Onias, and to prove that this was the name 
of the place which he had founded. Notwithftanding 
the account given by Jofephus (Antiq. lib. xiii. c. 3.) of 
the temple of Onias, and the occafion of its being built, 
Bryant conceives that the place allotted to him for this 
purpofe was not Heliopolis, but Onium, the fituation of 
■which was exterior with relpeft to Egypt; and this was 
fo fimilar to the ancient On, or Heliopolis, that it ob¬ 
tained that name; a name which it never received till 
after it was built; and then the prophecy was made ufe 
of by Onias and his friends to eftablifti the temple when 
finiftied, and to fanftion their proceeding. As this tem¬ 
ple was built in imitation of that at Jerufalem, it did 
not long furvive it. Vefpafian, it is faid, gave orders for 
its deftrudtion 5 though fome writers defer the demoli¬ 
tion of it to the time of Trajan; the temple upon 
Mount Gerizim having been deftroyed long before, pro¬ 
bably when Hyrcanus took Samaria. See Bryant’s Ob- 
fervations, &c. Dili', iii. 
O'NA, a river of Rufiia, which runs into the Uda at 
Mungalova, in the government of. Irkutlk. 
O'NA, a town of Peru, in thediocefe of Lima: thirty- 
five miles north-north-eaft of Loxa. 
O'NABAS, a town of New Mexico, in the province of 
Hiaqui: fixteen miles north of Riochico. 
ONA'GER,/ Thewildafs. SeeEouus afinus, vol. vi. 
p. ggg.—An ancient machine for throwing ftones. See 
Artillery, vol. ii. p. 231. 
ONA'GRA,/. in botany. See Jussieua, Mentzelia, 
and CEnothera. 
O'NANCOCK, a town of the ftate of Virginia. Lat. 
37. 4.5. N. Ion. 75.40. W. 
O NANG-SIUEN', a town of Corea: forty miles fouth- 
fouth-weft of Kang. 
ONA'NIA, or O'nanism,/. The crime of felf-pollu- 
tion, mentioned in Scripture to have been committed by 
Onan, and punilhed in him with death. 
This praftice, however common, hath among all na¬ 
tions been reckoned a very great crime. . In Scripture, 
befides the inftance of Onan above mentioned, we find 
felf-polluters termed effeminate, unclean, filthy, and abo¬ 
minable. Even the heathens, who had not the advantage 
of revelation, were of the fame opinion, as appears from 
the following lines of Martial: 
Hoc nihil ejjeputcs! fcehts efi, mild crede ; fed ingens 
Quantum vix animo concipis ipfe tuo. 
You think ’tis nothing! ’tis a crime, believe ! 
A crime fo great you fcarcely can conceive. 
Tifiot, a French phyfician, has publithed a treatife on 
the pernicious effefls of this fliameful praftice, which ap¬ 
pears to be no lefs baneful to the mind than to the body. 
He begins with obferving, that, though excels in natural 
v-enery is produdtive of very dangerous. diforders, yet 
an equal evacuation by felf-pollution, which is an unna¬ 
tural way, is produdtive of others Hill more to be dreaded. 
The confequences enumerated by Dr. Tilfot areas follow; 
1. All the intellectual faculties are weakened ; the me¬ 
mory fails ; the ideas are confufed ; and the patients are 
fubjeft to giddinefs ; all the fenfes, efpecially thofe of 
feeing and hearing, grow weaker and weaker, and they 
are fubjeft to frightful dreams. 
2. The ftrength fails, and the growth in young per- 
fons is coniiderably checked. Some alfo become hypo¬ 
chondriac or hyfteric, and are affliCled with all the evils 
which attend thefe diforders. Others are afflicted with 
coughs, flow fevers, and ccnfumptions. 
3. The organs of generation are alfo affeCted; and the 
femen is evacuated on the flighted: irritation. Numbers 
are afflicted with an habitual gonorrhoea, or tabes dorflilis, 
which entirely deftroys the vigour of the conftitution ; 
and at length impotence, in a greater or lefs degree, is the 
never-failing confequence of this deteltable vice. 
O N C 
ONA'NO, a town of Italy: five miles fouth of Aqua» 
pendente, and forty-eight north-weft of Rome. 
O'NANS, a town of France, in the department of the 
Doubs: thirteen miles north-eaft of Baume les Dames, 
and twelve north-weft of Blamont. 
ONA'PA, a town of New Mexico, in the province of 
Hiaqui: forty miles north-north-eaft of Riochino. 
ONARUS, a prieft of Bacchus, who is fuppofed to 
have married Ariadne after fhe had been abandoned by 
Thefeus. Pint, in Thef. 
O'NAS, a town of Japan, in theifland ofXima: twenty- 
two miles fouth of Funai. 
O'NATE, a town of Spain, in Guipufcoa : twenty-two 
miles north-eaft of Vitoria. 
ONATE'YA. . See St. Pedro. 
ON'CAN, a village in the Ifle of Man, rather more 
than two miles from Douglas. The church is dedicated 
to Onca, the mother of St. Patrick. In the church-yard 
are ufually buried the deceafed aliens of Douglas. From 
the high ground of this parifli, and from Clayhead, are 
fine views of the fea, ufually enlivened by coal-brigs 
trading between Cumberland and Dublin, and of fmaller 
veflels failing in or out of Douglas harbour. From On- 
can to Douglas is a pleafant walk over the funds. We 
approach them by a mountain-cafcade, which fome years 
ago turned the wheel of a corn mill, now burned down ; 
and further on, pafs another fomewhat fimilar; both 
being deftitute of trees and bufhes. Woods's IJle of Mem. 
ON'CE, adv. [the genitive cafe of one; amp, aney, Sax. 
of an.] One time.—Trees that bear mail are fruitful but 
once in two years; the caufe is, the expence of fap. Bacon. 
O virgin ! daughter of eternal night, 
Give me this once thy labour, to fuftain 
My right, and execute my juft difdain. Dryden. 
A Angle time.—Who this heir is, he does not once tell us= 
Locke. —The fame time: 
Fir’d with this thought, at once he ftrain’d the breaft, 
And on the lips a burning kifs imprefs’d. Dryden. 
At a point of time indivifible.—Now that the fixed ftars, 
by reafon of their immenfe diftance, appear like points, 
unlefs fo far as their light is dilated by refraftion, may 
appear from hence, that, when the moon pafles over them 
and eclipfes them, their light vanilhes, not gradually, like 
that of the planets, butaliat once. Newton. 
Then night came on, not by degrees prepar’d, 
But all at once; at once the winds ariie. 
The thunders roll. Dryden s Cimonand Ipldg. 
One time, though no more: 
Fufcinus, thofe ill deeds that fully fame, 
In blood once tainted, like a current run 
From the lewd father to the lewder fon. Dryden. 
At the time immediate.—This hath all its force at once, 
upon the firft impreflion, and is ever afterwards in a de¬ 
clining ftate. Atterbury. —Formerly ; at a former time : 
My foul had once fome foolifii fondnefs for thee ; 
But hence, ’tis gone. Addifon. 
At a future time. Obfnlcte. —The wifdom of God 
thought fit to acquaint David with that court which he 
fliall once govern. Bp. Hall's Contempt.—Once feems to be 
rather a noun than an adverb, when it has at before it, 
and when it is joined with an adjective ; as this once, that 
once. 
ON'CHA, a town of Hindooftan, in the circar of Go- 
hud : eighteen miles fouth of Bandera. 
ONCHID'IUM, /. the Bengal Slug ; in helmintho¬ 
logy, a genus of gelatinous worms.—Generic characters: 
Body oblong, creeping, flat beneath ; mouth placed be¬ 
fore ; feelers two, fituate above the mouth ; arms two, 
at the fides of the head : vent behind, and placed beneath. 
There are but two fpecies at prefent known. 
x. Onchidium typhas. This fpecies was difeovered, 
and the genus inftituted, by Dr. Buchanan, and de- 
feribed 
