[ 2 95 ] 
contrary to my ufual cuftom ; but this cafe required 
it : thete ftrange bodies were to be removed, if pof- 
fible ; that organ muft be injedted. and conftquemly 
the canula was abfolutely neceffary. The patient, 
who bore the operation exceedingly well, was blooded 
two hours after it : fhe had a pretty good night, and 
was blooded again the next morning. 1 left one of 
my pupils with her, and return’d to Rouen. 
The canula, which I left in the wound, was of 
the common fort, and therefore too narrow to admit 
of fearching in the difealed part, and to give iffue to 
thofe excrefcences, which we ought to endeavour to 
difengage and bring away in this treatment : befi des y 
it is extremely difficult to make the canula remain 
in the wound. 
/ s foon as I got to Rouen, I order’d the canula 
(Plate IV. Fig. i.) to be made; the advantages of 
which above the old one are : 
1. To afford a wider paffage for the fubftances 
that are to be evacuated and introduced. 
2. To fecure the inftrument in the bladder, by 
its own ftrubture chiefly, and particularly by the 
fwelling at BB. 
3. The neck A A, which is at the balls of the 
fwelling, is embraced by the neck of the bladder ; 
whereby the furgeon may be fure, how much of the 
canula enters the bladder : and the openings CC, 
being immediately above the fwelling B , are fixed at 
the lowed: part of the bladder. 
Fig. 2, 3, 4, of the fame plate reprefent the fame 
canula as above deferibed, but with further im- 
provements for cafes, which require the evacuation 
of grofs fubftances, the paffage for which cannot 
be 
