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lock'd on all the Points of the Compafs but three ) and the Land-Horizon exceedingly rugged and uneven.,.
4. Fekm Obftrcaary. Father Le Co^i^defcribes ajyery
made his chief Obferver.
The Inftruments are exceedingly large ; but the Divi- lions lefs Accurate, and the Contrivance, in fome fefpeas, lefs Commodious than thofe of the Europeans. Thechief are anArmillaty, Zodiacal Sphere of 5 Fans feet Diameter, an Equinoctial Sphere (Sfeet Diameter, an Azimuthal Ho- rizon 6 feet Diameter, a large Quadrant 6 feet Radius, a Sextant 8 feet Radius, and a Celeftial Globe 6 feet Diameter.
OBSESSION, the Action of being beret by an Evil Spirit ; which, without entrihg the Body, torments, and, as it were, befiesres the Perfon without : In which it differs from Foffefion. See Possession.
The Marks of Obfefon, according to fome, are a being hoifted into the Air, and thrown violently down without being hurt ; fpealing Languages never learnt^; having an Averlion to all Acts and Offices of Religion, cjc.
Some Phyficians look on all Cafes of Obfejfion as Natu- ral, and curable by natural Medicines, particularly an Un- guent tall'd Unguentum Carriobleri, with Purgatives, or Vomitives.
Of this Opinion is Doctor Gabriel Clauder, Member ot the Leopoldine Academy ; which he flrengrhens with the Teftimony of fromamms, in his Treatife de Fafcimtionibus^ ; Ganfius de Coralliis, who obferves, that it has been conleis'd by many Witches and Sorcerers, that the Plant Millepertius, Hypericin, and other Simples, l$c. incommode them ter- ribly, and prevent their Operations,
He confirms this Sentiment hence, that the Devil in thofe he thus befets.makesufe of the Melancholic Humour or the atra Bilis, and the grofler Impurities of the Blood, without always acting immediately of himfelf. For which he refers to the Books of Melcbior Sebizius mA Jerom Jordan, de Dhino in bomine i and gives the Procefs of a Cure of a manifeft Obfefon of a Child of a Year old at Delitfcbeltmrg, three Leagues from Leipfic.
OBSIDION ALIS, an Epithet the Romans gave to a fort of Crown wherewith they honour'd fuch of their Generals as had delivered a Roman Army befieged by the Enemy, and had obliged them to decamp. See Crown.
It was alio call'd Gramme*, becaufe made of Grafs, or Herbs found on the Spot, or Soil.
'Twas the Soldiery who beflow'd this Crown ; which, doubtlefs, was the reafon of its not being of a more pre- vious Matter.
The Word comes from the Latin Objid'm, Siege.
OBSTRUCTION, in Medicine, a lett or ftoppage of the Paffage of the Humours in the Body of an Animal. See Disease.
ObfiruHions arc fuppofed to arife from the grois Parts ot the Blood, detain'd in the Extremities of the Veffels, and thus blocking them up. ."|
Some Phyficians doubt whether there be any fuch thing as ObfiruHions in the Vifcera ; and rather attribute the In- conveniencics ufually afcribed to ObJiruSieas, to the Acrimo- nies and Crudities of the Stomach : But their Reafons are not convincing. 'Tis true, Objiruilions may not perhaps befo frequent as is ufually fuppofed ; and many of the Symptoms afcribed to them, are doubtlefs owing to Dif- onlers of the Stomach ; but then there's no denying that there are any Objiruilions at all in the Vifcera, &c. Schir- rus's, and other kinds of Tumours are incontellable Proofs hereof. See Tumour, Schirrus, ££c.
ObfttuSims frequently prove theCaufes of Dropiies. See Dropsy.
OBTURATOR, in Anatomy, a Name given to two Mufcles of the Thigh ; by reafon of their {hutting, or co- vering up the Foramen or Aperture between the Os Pubis, and the Hip-Bone.
The Obturator interim and marfupialis are the two Parts, or Divisions thatmake theGemini. SccGemini and Ma&- supialis. ,,■,., , . „
The Obturator externus arues rlelhytrom the exterior Mar- gin of the Os Pubis Qinc\ Ifcbium, and is inferted tendinous at the Root of the great Trochanter.
OBTUSE literally imports blunt, dull, eke. in oppofition loacue, fiarp,brish,&c- See Acute, tfc.
Obtuse single, in Geometry, an Angle of more than 90 Degrees, i. e. more than a Quadrant of a Circle ; or an Ancle grearer than a right Angle. See Angle.
Obtuse-ancled Triangle, is a Triangle one of whofe Angles is oki</e. See Triangle.
OBVENTIONS, Obventiones, in our antient Law- Books, fignify Offerings.
Sometimes the Word alfo fignifies Kents, and Revenues properly of Spiritual Livings.
OCCASIO, in oiir antient Law-writers, is taken for a Tribute which the Lord im'pofes on his Vaffals or Tenants, Propter occajiones bel'orum ££> aliarum Neceffitatum.
And hence Occufionari fignifies to be charged or loaded with Payments;
OCCASIONAL Caufe, £J?c. fee Cause, $gc.
OCCIDENTAL, a Term ufed chiefly in refpecl of Com- merce, to diftinguifll Commodities brought from the Weft- Indies, i. e. Ahhicai horn thofe brought from the Eafi- bidtes, which are farct to be Oriental. See Orien- tal
In this fenfe we fay, Occidental Bezoard ; fee Bezoard, Occidental Fearl ; fee Pearl.
OCCIPITAL, in Anatomy; a Term applied to the Parts of the tfctiputj hro'f the hinder Part of the Head. See Occiput. , ..,
Occipital hone, fee Occipitis Os.
OCCIPITALIS, or Occipital Mufcles, are a Pairo'f Mufcles of the Head, whole Origin is in the fame Place with that of the> Frontalis, i.e. in the upper Part of the Head near the Vertex, but which go a quite oppofite Courfe, viz. from before, hindwards, and are inferted into the lower Parr of the hairy Scalp, or Skin of the Occiput; which' they ferve to ('raw upwards. ,
Dr. Brake obferves, that the Occipitalis and Froiiidjis are one continued digailric Mufcle on each fide ; thai Part call'd the Occipitalis, aher a fmall Afcenr, becomesa rhin Tendon and marches over the whole Bregma, where it divides ; the one Part going on to the Os ~Jugale, the other, growing rle/hy^ acquires the Name Frontalis. See Front alis.
OCCIPITIS Os, or Os piorw, in Anatomy, the fourth Bone of the Cranium ; (o call'd from its fituation in the Oc- ciput. See Occiput.
"lis the hardell and thickeft of all the Bones of theCra- nium. Its Figure is triangular. In new-born Children itis divided into tour; but grows up, and becomes one in time.
It isjoinMto the Bones of the Sinciput, at the Lambdoidal Suture j as likewife to the Petrofa, and Os Spbenoidet at the Sphenoidal Suture.
The Parrs of rhis Bone are either folid, or hollow, i.e. empty. The folid are two Proceffes, call'd Corona. The hollow Parts are either Foramina, or Sinus' s.
The Foramina are either Common, or Proper : The Common are two, one on each Fuls common with the OJfa Fetrofa, affording a Paffage to the Nerves, Far Vagum, and to the internal Jugular Veins.
The proper Foramina are five : The firft is very large, and thro this it is that the fpinal Marrow paffes. Twe others give paffage to the Nerves of the Tongue, and the two laft an entrance to the cervical Arteries. See Nerve, $£>c.
It has two large Sinus's within-fide, for the reception of the two Hemilpheres of the Cerebellum. See Cerebel- lum.
On each fide the Foramina which give Paffage to the fpinal Marrow, is ufually a Procefs lined with a Cartilage, articulated with the firll 1'ertebra of the Neck. In lieu of this, is fometimes only a Prominence of the Bone j which, or the Procefs where 'tis found, receives the Infertions of the Mufcles of the Head, whereof there are ten, -viz. the: Par fplenium, Far complexion, Far reilum majus externum, Far reilum minus externum, Far obliauum fupenus, Obliauum intcrius. Far Maftoideum, Reffum internum majus, Reilum in. ternum minus, and ReFlum laterale 5 each of which fee in its proper Place.
OCCIPUT, the hinder Part of the Head, or Skull ; or the Part wherein is the Os Occipitis. See Head, Cra- nium, £S?c.
Scultetus obferves, that the Cauterization of the Occiput- is very frequent in many Places.
OCCULT, fomething fecret, hidden, or invifible.
The Occult Sciences are Magic, Necromancy, Cabbala, i$c. See Magic, igc.
Agrippa has fcveral Books of Occult Fbllofopby, full of the vainell, wildeft Dreams j and Fludd nine Volumes of the Cabbala, or Occult Science, wrapt up under Figures, or He* brew Characters.
Weak Philofophers, when unable to difcover the Caufe of an Effect, and unwilling to own their Ignorance, fay it arifesfrom an occult Virtue, an occult Caufe, an occult Qua- lity. See Quality, JfJe.
Occult, in Geometry, is ufed for a Line that is fcarce perceivable, drawn with the Point of the Compaffes, or a black-lead Pencil. See Line.
Occult, or dry Lines, are ufed in feveral Operations ; as the railing of Plans, Defigns of Building, Pieces of Per- fpedtive, i£c. They are to be effaced when the Work is finifhed.
GLI OCCULTI, ofBrefcia, in Italy, are the Academifls ofthatCity. See Academy.
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