1 3*7 ] 
It fometimes happens, after this operation, that 
the pupil lofes its circular figure : which, I imagine, 
is owing to the great tendernefs of the iris, that, up- 
on the leaft violence, is fubject to be ruptured • and, 
I fuppofe, in this operation, a flight preffure from 
the back or the flat of the blade may have pro- 
duced the accident in the inflances alluded to. Pof- 
libly the fudden dilatation of the pupil, from the 
rapid paffage of the cataract through it, may fome- 
times occafion it j but the following hiftory would 
induce one rather to afcribe it to the caufe, which I 
firft mention’d. 
Before I had thought of the knife for opening the 
cornea, I ufed the fciffars, as Monf. Daviel directs ; 
and, in a certain patient, after I had made the 
wound of the cornea, and was going to comprefs the 
eye, for the expulficn of the cataract, I difcover’d, 
that, from the difturbance I had given to the hu- 
mours by the foregoing procefs, it was funk almofl 
as much as if it had depreffed by a couching needle. 
I therefore left it in that fituation, and the man after- 
wards faw very well ; tho 1 the cataract remained vi- 
fible fomething below the pupil. 
Now, in this inftance, the cataract had not paffed 
thro’ the pupil ; and yet it was lacerated, fo as to 
lofe its circular form : but, whatever may be the 
caufe, I do not find, that the accident itfelf proves 
prejudicial to the fight. 
I fhall finifli thefe obfervations with a remark on 
one difad vantage, to which this operation and couch- 
ing are incident ; and that is a poflibility of an in- 
complete gutta ferena being complicated with the 
cataract. It has, indeed, been a rule with furgeons, 
3 tho* 
