Page:Cyclopaedia, Chambers - Volume 1.djvu/620

 DUN

[ 254 ]

DUP

Royal, are filled, Moft high, moji mighty, and Illufirious 'Princes.

DUKE-DUKE, a Quality given in Spain to a Grandee of theHoufe of Syfoa, on Account of his having feveral Dut- chies, by the uniting of two confiderable Houfes in hisPerfon.

Don Rodrigo de Sylva, eldcft Son of Don Ray Gomez de Sylva, and Heirof hisDutchics, and Principalities, married the eldcft Daughter of the Duke de f Infant ado ; In Vertue of which Marriage, the prefent Duke de Pafirana, who is defcended therefrom, and is Grand-fon of Don Rodrigo de Sylva, has added to his other great Titles, that of Ztefee- 23»ftfe, to difiingui/h himfelf from the other Dtikes, fome whereof may enjoy feveral Dutchies, but none fo consider- able Ones, nor the Titles of fuch eminent Families.

DULCIFYING, the Sweetening of any Thing : a Term ufed in Phyfkk, for rendering a Fluid lefs acid, and rough, either by taking away its Salts, or breaking their Points, or covering 'em with fomething fmooth, and foft.

DUMBNESS, the State of a Pcrfon who wants the natu- ral Ufe of Speech. People born deaf, are fa id to be all na- turally dumb, as not being able to learn Words. See Deaf- ness.

fDumbnefs is fometimes the Rcfult of the Want, or even the ill Conformation, of the Tongue. See Tongue.

Yet in the 3d Tome of the Ephem. German, we have an Account of a Book, entitled, Jac. Rolandi Agloffoftomogra- phia, Jive Dejcriptio Oris fine Lingua, quod perfetle lo- quitur, Sic. See Mute.

DUNG, in Agriculture, and Gardening. Sec Manure, and Compost.

DUNGEON, DONGEON, or DONJON, the moft elevated Part of a Caftle built after the ancient Mode ; fer- ving as a Watch-Tower, or Place of Obfervation. See Castle.

In fome Ca files, asfch.at.of Vincennes, &c. the 2)ungeon t or Donjon, ferves as a Prifon for Perfons they would have the moll: fecurely kept ; whence our Word 'Dungeon.

Fauchet derives Dungeon from Domicilhrm, in that the Dungeon being the ftrongeft Part of the Caftle, was ufually the Lord's Apartment. Menage derives it horaDomnionus, which in fome ancient Writings we find us'd in the fame Senfc. Others derive it from Domus Jzilii defaris, or Do- mus Jugi ; And others from Domus Juliani, the Emperor Julian having built feveral fuch Caftles in the Gauls, where- of there is one ftill ftanding in Lorraine, call'd Dom Ju- lien. Du Cange derives the Appellation from Duno 'am Colle JEJificatum, which the barbarous Writers have alter'd into Dunjo, Duvgeo, Dongio, Dangio, Domgio, and Dom- mo.

DUO, in Mufic, a Song, or Composition to be performed in two Parts only; the one fung, and the other play'd on an Inftrument ; or by two Voices alone.

It Is alfo call'd a Duo, when two Voices fing different Parts, accompanied with a Third, which is a thorough Bafs. Lnifons and Octaves muft rarely be ufed in Duo's, except at the Beginning and End.

DUODENA Arteria, zx\&Vena, a Branch of an Artery, which the Dtiodenum receives from the Cceliac ; to which anfwers a Vein of the fame Name, returning the Blood to the 'Porta. See Vein, and Artery.

DUODENUM, in Anatomy, the firft of the Inteftina tenua, or frnall Guts; being that which receives the Food half chylificd from the Stomach. See Intestines.

It has its Name Duodenum, as being about tivelve Fin- gers Breadth, long; On which Account, fome alfo call it 1)o dec a da Bylum.

The 'Duodenum arifes from the Pylorus, or right Orifice of the Stomach; whence defcending towards the Spine, from Right to Left, quite ftraight, it terminates where the Cir- cumvolutions of the reft begin.

Its Coats are thicker, and its Cavity, or Canal lefs than any of the other Interlines. At its lower End are two Ca- nals, opening into its Cavity, one from the Liver, and Gall- Bladder, call'd the Duclus Communis Cholidicus ; and the other from the Pancreas, call'd Pancreaticus. See Cho- lidicus, and Pancreaticus.

The Duodenum is quite ftraight ; but the Intefiinum Je- junum makes divers Windings, "and Inflexions : The reafon is, that the Bile, and Pancreatic Juice mixing at the Begin- ning thereof, or at the End of the Duodenum, would other- wile precipitate not only the grofs Parts of the Excrements, but alfo the Chyle itfelf, too haftily. See Bile, Excre- ment, c2c.

DUPLA, DUPLE, DOUBLE Ratio, is where the Ante- cedent Term is double the Consequent ; Or, where the Ex- ponent of the Ratio is 2 5 Thus 6: 3 is in a Duple Ra- tio. Sec Ratio.

Suh-Dvpz,z, <y//£-PouBi,E Ratio, is where the Confequent

Term is double the Antecedent 5 Or, the Exponent of the

Ratio is \. Thus, 0, : 6 is in a Sub-duple Ratio. See Ratio.

DvphA-Sefquiattera

VvaLA-Superbipartie?ts tertias

\-Ratio. -<See Ratio,

DUPLICATE, a fecond Inftrument, or A<3, in Writing j as a Brief, Writ, Difpatch, $$c. Or a Tranfcript, or Copy of another.

'Tis ufual to write a Duplicate, when it is apprehended the firft Difpatch, £?c is loft.

In Chancery, Duplicate is particularly us'd for fecond Letters Patent granted by the Lord Chancellour, in a Cafe where he bad formerly done the fame.

The Word is form'd from the Latin Duploma, or Du- plum.

Duplicate Ratio muft be well diftinguifh'd from Duple.

In a Scries of Geometrical Proportions, the firft Term to the third is faid to be in a Duplicate Ratio of the firft to the fecond; or as its Square is to the Square of the fecond : Thus, in 2, 4, 8, 16, the Ratio of 2 to 8, is Duplicate of that of 2 to 4; or as the Square of 2 to the Square of 4 ; wherefore Duplicate Ratio is the Proportion of Squares, as Triplicate is of Cubes, ci?c. and the Ratio of 2 to 8, is faid to be compounded of that of 2 to 4, and of 4 to 8. See Ratio, &c.

DUPLICATION, Dotibling, in Arithmetic, and Geome- try, the multiplying a Quantity, either difcrete, or continued, by tivo. See Multiplication.

The Term is chiefly us'd in the Phrafe, Duplication of the Cube, which is a famous Problem fought by the Geome- tricians thefe two thoufand Years. See Cube.

It was firft propofed by the Oracle of Apollo at Del- phos 5 which, being confultcd about the Manner of {topping a Plague then racing at Athens, return 'd for Anfwer, that the Plague fliould ceafe when his Altar, which was Cubi- cal, fljould be doubled. Upon this, they applied themfelves, in good Earneft, to feck t\\z Duplicature of the Cube, which hence forwards was call'd the Delian Problem. See Pro- blem.

The Problem is only to be folv'd by finding two mean Proportionals between the Side of the Cube, and double that Side ; the firft whereof will be the Side of the Cube doubled: as was firft obferv'd by Hippocrates Chius. See Propor- tional.

Eutochius, in his Comments on Archimedes, gives feveral Ways of performing it by the Mefolabe. Pappus Alexan- drinus, and his Commentator Commandin, give three Ways: The firft, according to Archimedes $ the fecond, according to Hero ; and the third, by an Inflrument invented by pappus^ which gives all the Proportions required.

The Sieur de Comiers has likewife publifti'd an elegant Dcmonftration of the fame Problem, by means of a Compafs with three Legs : But thefe Methods are all Mechanical.

DUPLICATURE, in Anatomy, a Doubling, or Folding of the Membranes, or other like Parts ; as the Duplicatures of the Peritoneum, of the Omentum, of the Pleura, ike. See Peritonaeum, Omentum, Pleura, &c.

In the Hiftory of the French Academy for the Year 17 14. an Account is given of a young Man, who died at the Age of 27 Years, in the Duplicature of whofe Meninges were found little Bones, that ieem'd to proceed out of the inner Surface of the dura Mater, and with their acute Points fti- mulatcd the pia Mater.

That Duplicature of the Peritoneum, wherein the An- cients placed the Bladder, is not found by the modern Ana- tomifts. Dionis.

Fabridus ab Aquapendente firft difcover'd the Duplica- ture of the Cuticula. Sec Cuticle.

DUPONDIUS, in Antiquity, a Weight of two Pounds : Or a Money of the Value oftwoAs's. See As.

As the As, at firft, weigh'd a juft Pondo, or Libra ; the Dupondtus, then, weigh'd two. And hence the Name.

And tho' the Weight of the As was afterwards diminifh'd, and of Confequence that of thcDup07idius alfo 5 they ftill re- tain' d the Denomination. See Pound, and Libra.

DURESSE, Hardpip>, in Law, is, where a Pcrfon is kept in Prifon, or reftrain'd of his liberty, contrary to Order of Law ; or threatcn'd to be kill'd, maim'd, or beaten.

In which Cafe, if a Perfon fo in Prifon, Or in Fear of fuch Threats, make any Specialty, or Obligation, by reafon of fuch Imprifonment, or Threats; fuch Deed is void in Law : And in an Aclion brought on fuch Specialty, the Party may plead, that it was brought by Dureffe.

Brook, in his Abridgment, joyns Dureffe and Manaffe to- gether, i. e. Duritiam & Minas, Hardihip, and Threatnings.

DURA Mater, or DURA Meninx^ a ftrong, thick Mem- brane, which lines, or covers all the inner Cavity of the Cra- nium, and includes the whole Brain ; being it felf lined on its inner, or concave Side by the pia Mater, or Meninx tenuis. See Meninges.

The dura Mater flicks very clofe to the Bafis of the Skull, and its Sutures by the Fibres, and Veftels it fends to the Pericranium. See Brain, and Cranium.

It is faften'd to the pia Mater, and the Brain, by the Veffels which pafs from one to the other. It gives a Coat, or Covering to all the Nerves which rife from the Brainy

and