22 Mr. Griffiths' Description of an Instrument 



strument for the same purpose had been invented, and used with 

 success in France, and which was somewhat on the same principle, 

 excepting that it had no curve, it having been found that a 

 straight instrument might be passed into the bladder of many 

 persons. 



Notwithstanding what was said of the success of this con- 

 trivance, I conceived it would be very desirable to form one 

 which would be better adapted to the natural curve of the urethra, 

 and with which there would be less danger of injury to the blad- 

 der in attempting to seize the Stone. Under this impression I 

 determined to make another attempt, and for this purpose I ap- 

 plied to Mr. Ferguson, a very ingenious Surgeon's Instrument 

 maker, in Castle-Street, Leicester Square ; he entered fully into 

 my plan, and was of very great assistance in carrying it into exe- 

 cution, and completing the instrument hereafter described. 



The instrument (Plate III. Fig. 1.) for the sake of convenience, 

 is represented somewhat smaller than the original model ; it con- 

 sists, in the first place, of a tube twelve inches long, A A re- 

 sembling a catheter, with the exception of its being open at both 

 ends ; B is an arm coming off, which connects the whole together, 

 and at the same time serves for a handle. Fig. 2, is a stilet^ with 

 a knob at the end, which fills up the opening at the extremity of 

 the canula, so as to enable it to be passed into the bladder without 

 injury to the urethra, after which it is to be withdrawn, and the 

 apparatus for seizing the stone is then to be introduced ; it con- 

 sists of a tube six inches longer, and about the eighth of an inch 

 less in diameter than the first, the anterior part of which is made 

 flexible, to enable it to take the curve of the canula, in the same 

 manner as the old elastic catheters were constructed, which is by 

 means of winding up a narrow strip of silver into a spiral form; 

 part of this is seen at D, the anterior extremity, which, in Fig. 1, 

 is concealed in the canula, and is represented at F F, Fig. 3. The 

 surface of this tube is divided by ridges into four compartments, 

 which at the same time keep it steady* and allow space for the two 

 narrow watch springs G G, to pass between the two tubes, and 

 prevent their catching in each other ; at the extremity is a collar 



