Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/686

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the fraflurcd parts recede from one another, Come degree of Extmfion is neceffary, which muft always be fmtcd to the diftortion of the limb. The greater diftancc there is between the extremities of the divided parts of the bone, fo much the fhorter will the limb become from the natural contraction of the mufcles, and the Extenfan mutt be proportionibly the greater ; but, in thefe cafes, every thing is to be done ten- derly, and with great care. I. The patient is to be kept very firm and fteady ; the pofture of the body muft be, in this operation, different, according to the different circum- ftances of the cafe ; fometimes fitting, and fometimes lying, are the moll proper. 2. An afliftant muft fupport the limb with his hands, both above and below the fractured part. 3. The perfon who holds the lower part of the limb, muft extend it ftrongly and equally, till the fractur'd bone can be replaced ; but when the furgeon is called at fomc diftancc of time from the accident, and a tumour and inflammations are come on ; it is beft, in fuch cafe, to defer the Extenfion of the parts till thefe fymptoms arc removed, by letting blood, loofening the bowels, giving the patient large quantities of aqueous fluids, and prel'cribing the proper internal remedies for abating inflammations, and fomenting the parts with warm difcutient decoctions. Thefe applications will ufually fuccced fo well as to lake down the inflammation, ill twenty-four hours, in fuch a manner, that the Extenfan of the limb may be fafely attempted ; but when they do not take place fo I'ud- denly, they are to be repeated till they have the ifcfired effect ; and where the common fomentations fail, the following has often very great and happy fuccefs : Take two or three handfuls of fcordium, and boil them for about a quarter ot an hour in a pint of water, with fix ounces of rcctify'd fpirit of wine, afterwards mix with it an ounce of common fait, and half an ounce of fait petre, and ufe this to the inflamed fraiSlur'd limb. To make the proper Extenfion of a limb, the furgeon muft, while it is kept at its proper length by two af- fiftants, direfl it with his hands, fometimes a little one way, fometimes another, putting it into different politions, as the nature of the cafe fhall require, till the parts have recovered their natural fituation. This will be known by rhe icmilhon or abfence of pain, and by obferving, that the fraflur'd limb is of the fame length with the foundone ; and if thefe Tigris of fuccefs, in the operation, are wanting, there is great reafon to fuppofc, that the operation is as yet ineffectual, and the Exten- fan is to be repeated or continued till the bones arc evenly and nroperly replaced. Heijier\ Surg, p, 108.

EXTENSOR [Cycl.) — Extensor Digitorum Communis, a compound mufcle, very much rcfembling the perforatus and perforins, and lying on the outfide of the forearm, between the ulnaris cxternus and radialis externus. It is fixed above, by a tendinous extremity, to the pofterior and lower part of the external or great condyle of the os humeri ; and, by a tendi- nous adhefion on each fide, to the ulnaris and radialis externus. Jt has .likewife fometimes a fmall infertion in the radius; it is divided into four mufcles, like the perforatus and performs, and four long /lender fmall tendons. Three of thefe tendons pafs through the common external annular ligament of the carpus ; and the fourth, which goes to the little finger, and ■which has fometimes its flefhy portion diftinct from the reft, panes thro' a particular ring of the fame ligament. Afterwards their: four tendons feparate as they go to the fingers, and, in their pillage, communicate with each other by oblique tendi- nous feries, chiefly near the heads of the metacarpal bones. The tendons of the middle and little finger are fometimes double, and yet communicate with the reft. Each tendon having reached the bafis of the firft phalanx, is flightly inferted therein by fome lateral expanfions, fixed in each fide of the bafis ; from thence it advances to the head of the fame phalanx, where it is divided into two flat por- tions, which, at the articulation of the firft phalanx with the fecond, leave fome diftance between them. About the head of the fecond phalanx they unite again, and are fixed in the

'. convex fide near the bafis in the third phalanx. The feparation of the two portions is, in fome fort, rhomboidal, and each portion is ftrerigthened by a common tendon of the lumbri- cales and interrolTci, and in the fmall fpaces between them are fmall tendinous frama, more or lefs trinfvcrfe. IViiiJIow's Anatomy, ,p. 199.

Extensor Digitoru/n Pedis longus, a long mufcle, flefhy in its upper part, but tendinous in the tower, lying between the tibialis anticus and peronieus maximus. It is fixed above by flefliy fibres in the outfide of the head of the tibia, and in- fide of the head of the fibula, in the upper part of the interof-

' feous ligament, thro' three fourths of the length of the fibula,

. and thro' the fame fpace, in the tendinous feptum belonging to the anterior angle of that bone. It fecms to mix fomc fibres on each fide with the two firft peronrei and tibialis anticus, and

. is very clofely united with the peronreus maximus. It con- tracts in breadth a little above the annular ligament, and, in paffing through it, is divided into three tendons, the firft of which is afterwards again divided into two. Thefe four ten- dons are inferted along the upper or convex fide of the bones of the four fmall toes. lVinflow'% Anatomy, p. 222.

I^XTENsolt Digitorum Pedis lirevis, a fmall complex mufcle, lying obliquely on the convex fide of the foot, called alio pe-

EXT

diem. It is .fixed in the upper and outer fide of the anterior apophyfis of the aftragalus, and in the adjoining part of the Upper fide of that bone. Thence it runs obliquely inwards and is divided into four flefhy portions, which terminate in four tendons. The firft is inferted in the upper part of the firft phalanx of the great toe, and the other three, joining with thofe of the Extenfor longus, are inferted along the convex Tides of all the phalanges of the three following toes. When there is a fifth tendon, which fometimes happens, it o-oes in the fame manner to the little toe. Iffnjlozv's Anatomy p. 223.

Extensor lndicis proprius, a fmall long mufcle, with a long fiender tendon, lying a little obliquely on the lower and outer half of the fore arm* between the ulna and the fore finger. It - is fixed by its flefhy body, a little higher than the loweit third part of _the outfide of the ulna, below the infertion of the Ex- tenfor polUd's, and it has likewife a fmall adhefion to the in- teroffeous ligament. From thence it runs down, ending in ;L diftinct tendon, without any communications, which having puffed through the annular ligament of the Extcnjor communis afterwards joins that tendon ivhich gucs to the index. // "m~ flow's Anatomy, p. 200.

Extensor Minimi Digiti proprius, a collateral or auxrlkiry mufcle of tlte Extenfor communis, of which it appears ahnurt always to be more or lefs a portion. It is fixed along the fu- perfor external half of the uln'a, from whence its long fmall tendoft runs d-own in company with the fourth tendon of the Extenfor communis, all the way to the little finger, where it joins it, and is inferted with it, Sometimes this mufcle is wanting, in which cafe the Extenfor communis fends a double and fometimes a treble tendon Co the little linger. Winjlow's Anatomy, p. 200.

Extensores Pol/icis Manus, two very diftinct mufcles, the firft, or longcft of which, is fometimes more, fometimes lefs, and fometimes altogether divided into two, in which cafe thefe: mufcles are three in number. They are fituated obliquely between the ulna and the convex fide of the thumb. The extenfor primus is a long mufcle, more or lefs double, and it fixed above by flefhy fibres, firft to the outfide of the ulna, near its upper extremity, below the anconeus mifior and in- fertion of the ulnaris. externus ; next to the in'terrolleous liga- ment, under the fupinator brevis ; and laftly, to the middle part of the outfide of the radius.

From thence it runs down, and paffes anteriorly over the lower part of the radius, and tendons of the fupinatnr longus and radialis externus; and being gradually divided, it termi- nates in two long flat tendo'ns, more or lefs fubdivided, which pafs together under a particular annular ligament, being only parted by fepta or fraena belonging to that ligament. The firft of thefe two principal tendons is inferted in the edge of the bafis of the firft phalanx, near the large tranfverfe liga- ment of the carpus; when this tendon is iubdivided, the other portion of it is fixed in that bone of the carpus which fuftains the thumb. The other principal tendon, which often belongs to a mufcle entirely diftinct from the former, is fixed in the convex fide of the bafis of the fecond phalanx, where it joins the tendon of the extenfor fecundus. On account of thefe different infertions of the two tendons^, this mufcle is, by fome authors, defcribed as two.

The Extenfor fecundus is fhorter than the firft ; it is fixed to the ulna below the former, and above the infertion of the Extenfor in- dicis proprius ; arid likewife to the neighbouring part of the inter- rofleous ligament. From thence it runs down obliquely ©n the middle part of the radius, where it has alfo a fmall adhefion ; after this it paffes thro' the fmall channel in the ftyloide apophyfis of the radius, thro' the annular ligament belonging to the tendons of the radialis externus, and over thefe tendons, being parted from them by a fmall ligamentary feptum. It is inferted in the convex part of the third phalanx near its bafis, having, as it pafles over the fecond phalanx, joined the fecond or collateral tendon of the firft Extenfor, more or lefs. Winjlow'% Ana- tomy, p. 196.

Extensor Pollicis longus., a thin fingle mufcle, lying between the tibialis anticus and Extenfor digitorum longus, by the laft of which it is almoft hid. It is fixed to the infide of the fibula, near the interoffeous ligament, from the neck down to the loweft quarter of that bone; to the interoffeous ligament thro' the fame fpace, and a little to the lower extremity of the tibia next the fibula. It there ends in a confiderablc tendon, which palling through a diftincf ring of the common annular ligament, and then through a membranous vagina, is inferted in the bafis of the firft phalanx of the great toe, and continued up to the fecond. inflow's Anatony, p. 221.

Extensor Proprius Auricidaris, in anatomy, a name given, by Albinus, and fome other late authors, to one of the mufcles of the hand, called byCowper, and others, the Extenfor mini- mi digiti. Vid, Supra.

Extensor Tarfi, inanatomy, a name given by Douglafs, and fome others, to a mufcle, more generally known by the name of the plantaris. See Plantaris.

EXTERMINATION, or Exterminating, {Cycl) in algebra, is ufed for taking away. Thus algcbraifts fpeak of exterminating furds, fractions, and unknown quantities, out of equations. See Madaur. Algebr. part 1. ch. 12. where