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Place the patient in the lame fituation as for couch- 
ing, either opening the eyelids with your fore-finger 
and thumb, or letting an afiifiant raife the upper eye- 
lid, whilfi you yourfelf keep down the under eye- 
lid. Then, with a fmall knife, the figure of which is 
here reprefented, holding its edge downwards, make 
a pundture through the cornea near its circumference 
into the anterior chamber of the eye, in fuch a dire- 
ction, as to carry it horizontally, and oppolite to the 
tranfverfe diameter of the pupil: after which you are 
to pafs it towards the nofe, through the cornea from 
within outwards, as near to its circumference, as in 
the firfi pundture. 
When you have made the fecond pundture, pufii the 
extremity of the blade one feventh of an inch beyond 
the furface of the cornea, and immediately cut the 
cornea downwards, drawing the knife towards you 
as you make the incifion. After this, you prefs 
gently with your thumb againft the inferior part of 
the globe of the eye, in order to expel the cataradt, 
and the operation finifhes, according to the different 
circumfiances, as in the manner propofed by Monf. 
Daviel. 
One extraordinary benefit feems to arife from the 
ufe of this fingle infirument, and perhaps from the 
fhape of its blade, which increafes in breadth all the 
way towards the handle : for, by this means, the 
pundfures are fo exadtly fill'd up by the blade, that 
very little of the aqueous humour is difcharged be- 
fore you begin to make the incifion, and confe- 
quently during this time, the cornea preferves its 
convexity ; whereas by ufing one infirument to punc- 
ture, and others to dilate, the cornea immediately 
becomes 
