1000000031

lTeat convenience

holding

it,

:lOd

lC<lning

on one fide or

other of the (aw. as we 6nd

necctTary.:

The trepan

ho·....,~

(ver, though allowcd

unhOllldy.

¡s the inrlrument maO:

ufed by lurgeons in othcr pa", o( E urope, upoo the fuppofa.

tion of

ItS

workanR 'l"'lckc.c lhan lhe trephine.

T he trephíne hc:re

prerented

of fuch a Chape as to

make it a coO\'enient dl!vator.

fUT

which purpofe

lhe

ex.–

lremities of il are

molde rough .

A key

take out the pio

E ,

when lhe

f:.lw

has

made an

imprdIion

decp enough to

be~worked

without lhe

belp o( it.

EXPLANATION of Fig.

2 .

Pla,e CLVUI.

convcnient forceps

take

OUt

1he

circular piece

of bone,

wheD

.does

nCI

(tick

Ihe faw: lhe

cantTivancc

by whieh they readily la)' hold of ir, is

m.ke

the extre

mides thu are

grafp

il,

with ao areh of Ihe Carne cicele

as lhe (aw

¡,

made. U pon

one o( the handlt:s, (here i, I4d.

ded. Jiu le el...

tO.,

tiCt

up any fmaJl fplin ter of bone.

lenticular: the fore·pan of iu blade is fharp, in oro

aer to {crape the lower edge of (he ori6ee of the

craniu1/1,

cafe any fplioter, (hould remaio "fter the operation; and

the

buuon

iu extremity receives the dull, that it may Rot

faJl OD the

br.in;

but tbere is feJdom .ny oee.Gon for this

infirumeot.

rugine or rafpatory, for fcraping bones in arder to

promote granulations of flelh . The handles

thefe

'\VO

.lan infl ruments are

wood,

whercas every pan of the otber,

lhould be

m.de

of {led.

Oflhe

CAT ,UACT .

TH' ear"'ao!!, c.Jled by the Latios

fuffujio,

i, • difeafe

.,r

the crytlalJine humour, rendering the whole body of it

"pake, fo th.. ,he ray'

light, which , in ,he qatural

tI..

onu

tranfparency. were tranfmiut"d to the

funica r(/ína,

become now toulJy intercepced, acd produce no effell.

This is pretty nearly the account delivered down to us

Hippocrates and the ancieot Greeks, who likewife knew

by rhe

n.me

oCglaucoma,

Anatomills have frequently ditfeéled the eyes of perfons

under this diforder a(ter. lheir death. and han fOUDd it to

be alway' an opacity

the eryllaJline humou" 'g'ee.bly

lo' the de6Dition of a

glaucoma':

th.~

by confequenee

"'e mwfl

underfiand the word.

cafarafl

aDd

g laucoma

CyDonymous terms.

The general criterion of the fltoefs of catar.aéb for the

peration,

iSAak.en

from their colour

the pe..,1

coloured~

and

thoCe of the colour of burnilhed iron. are efieemed proper

to eodure the o'eedle; the white are fuppofed milky, the

,reen .nd yelJow horoy and incurable.

The deprellion of a eatataél of aoy coloar would be the

cu.re

thae alone was the diHemper of the eye : but

ge..

8erally happens, that the yellow cararaéls adhere tO the

irÍl

fo firroly

to become immovcable

befides, when

Ibey follow in eonfcquenee of a blo\V, which i, often ,he

caCe, either tho cells of the vitreous humour are fo much

díflurbed aDd br oken, or the

relinll

afFelted , that a degree

blindoef, will remain,

tho~gh

,he catano!! be depretfed ,

To judee whether the catara(t adheres to the

iril ,

Y,ou eannot at once dillinguilh il by yoor Ggh" Ihut .he

llent'. ere, and rub the lids

linle; then fuddenly openine

h, you

will

perceive the pup;1 contraét., if the

cryll:~lIíne

humour do.. not preveot the .aion by irs adhefion : Aod

VOL.

NP 96.

whc.... this is the

cafe

in any kind of catarac!t, the operation

eun hardly be ad vi("d.

Another conl.dern.tion o( the &reaten moment , before

undenaking lhe cure, is tObe affu reJ o(

lhe

right (late of

lhe

Ilm;,a rel flla;

which is

very readily It:arnt, \Vllcrc there

is no adht::liotl of the Ca(arda, (rom lhe IIgh t

(;¡lIlOg

be.

tWt:en lhe

írÍ¡

and crylldlline humour, which ir the eye i!l

0 0 1

fenfibl6 or, it

is a

cenillin indicatlon of anothcr mal.tcy,

and íl.bColutely forbids the oper3tion. Generally this

ca.

tanét takes its rife from head.achs, con\'uHioo" and nervous

dilorders .

•

\Vhen none of ,hefe objeétions (orbid the operarioo , i,

m..y be thus done : B Jviog placed your patienr in a eOIl.

~ venitn[

light. and in

chalr luitable to the height of thac

you yourfelf fa, io, let a pillo

or t'NO be plaeed behi nd hi,

back,

fuch a maoncr,

that

Ihe body bending forward, the

'head may approach

near

tOyou; then inclining the h.;ad

Jiale backward upon the brean of your affiítanl. and cover.

ing tbe other eye fo as'

pre'fenl its rolling. Jet

the

affifl:.

ant lif, up the fuperior eye.lid, and yourfel( deprefs a Jiule'

the ¡oreflor one: Thís done, fir·ke the needle th rough the

JIU/ica conjunf/íva.

fomething Ices lhan one trnth of an ineh

from the

cornea,

even

with

the middle of the pupil. ioto

the po(lerior chamber, and gently endeavour to deprefs (he

cata.raét \Vith the tht fllrfaee of

¡t.

If,

after it (s difiodged,

rifes aEain, thougb nOl with m".ch elallici(y. ie mult a.

gain and .

.gíl.in

be pulhed dOWQ.

If it is membraDous ; af.

ter the difeharge

the /luid, the pellicle mull be more

broke and depretfed : if i, is uoiformly fluid, orexceedingly

clatlick, we R1Ull: not continue to endanger a terrible iD.

ftarnm:uion, by a niD auempt to Cucceed. If a cataratl of

the right eJe is lO be couched, and the rurgeon cannol

ure

his lef, hand fo dex,erouny

his right, he lOay place him–

fei f behind the parien" .od ufe hi, righ , hand.

We have DOl recommcnded the

fp~'ulum

, culi,

bccaufe,

upon the difcharge of the aqueous humour through the

pune.

ture. the eye. beiDg

romew~aeemptied,

mOre readily admits

of .he dep,ellion of the eryllalline humour, than \Vhen pretf"d

upon by the iollrument.

As tOthe method of treating the fucceeding inU,¡mOla.

tion, bleeding and other geotIe evacuation, are fouod ab·

folutely oecetfary:

Cutling

Ihe

T HE

are two caCes where this. operadon may be oí

fome fervice; one wheo the catana

from

its

adheGon

immoveable ; and the oeher, wheo the pupil of the eye

,otalJy c10fed up by • diford., of the mufeular fibres of the

íriJ,

whích graciually contraaing the orifice, at

Jan:

leavc~

the membrane qui,e imperfora,e. Thi,

!aH

dillemper ha.

hitherto beeo deemed incurable. The adhe60n of the ca. ..

tana has been conlidered

a fpecies of bliñdners DOt

"e relieved: but M r

Chefeldo,

has invented a method

,of

making an artificial pupil,

flitting the

irÍl,

which may

relieve in both the ¡nllances here fiated.

ID doing Ihis operation, the patient mu(l he placed as ror

eouehing, and the eye kept open and fixed by

the./J>ecul"I/I

oculi.

which is ..bfol utely neceffary hert:

theo introducing

the knife in the fame part of the

conjunf/itlo

you wound in

couching, inGnl1ate it with irs blade held horizoolally, and

lhe back of

towards you, betwe:en

Ihe lígQ11/enlum á lian

and circum(erence of the

irú,

ioto lhe aOlerior chamber of

the eye; and after it is advanecd 'o the fartbe, fadc of ir,

8 F

n..