VOL. XLVI.] PHILOSOPHICAL TBANSACTIONS. ()47 



use. This cuts only by its crescent ab, pushed forward, and moved alternately 

 /rom one side to the other, to assist its cutting. 



There are circumstances in which the knife fig. 8, may be preferable. 

 Forceps for extracting stones, and other foreign bodies, lodged in the parts 

 where the common forceps are of no use, are shown in fig. 9. The same me- 

 chanism just now described in the foregoing forceps, may be applied with advan- 

 tage to the forceps with which the stone is pulled out, and to other instruments 

 designed for extracting bullets, splinters of granadoes, pieces of iron, and other 

 foreign bodies. 



There are several cases in the cutting for the stone, in which no use can be 

 made of the common forceps : the most frequent is this ; when a stone, laid hold 

 of by the ordinary forceps, escapes from the instrument half-way, and so remains , 

 engaged in the incision. The expedient commonly taken, is to push the stone 

 back into the bladder, in order to have again the necessary room for managing 

 the forceps ; but besides the cruel pain in thus pushing back the stone into the 

 bladder, this foreign body may enter into the cellular texture v\hich surrounds 

 the bladder, and lodge itself there, and then the forceps not having any longer 

 that play which was endeavoured to procure to them, the stone will remain in 

 that fatal lodgment, without possibility of pulling it out, and the patient will die. 



The stone having stopped in the passage of the incision, you slide along the 

 body of it one of the cheeks of the forceps, a or c, well oiled, which will be 

 done without much trouble; the other cheek afterwards will pass on the other 

 side ; after which you join them, as shown above, taking care to press close the 

 extremity ac on the stone, and to leave the largest opening on the side of the 

 handle bd, as in fig. 10, both to hinder the stone from escaping, and to widen 

 its passage ; then, having well secured the screw g, you leave the screw f almost 

 at liberty. You grasp the instrument with both hands, as near the stone as you 

 can, and you draw the body out, managing it as is usual with the common forceps. 



A second case of cutting for the stone, where these new forceps will be of 

 great use, is this ; when the stone is exactly embraced by the internal coat of 

 the bladder ; whether it completely fills this whole organ, or that it fills part of 

 it, which may have closed itself on the stone; or that the stone has made itself a 

 lodgment or bed in the Inside coat of the bladder, prolonging itself towards the 

 cellular texture, which surrounds a small part of those inside coats. In short, 

 every foreign body lodged in the substance of any part of the human body, be it 

 of what nature it will, becomes the object of our instrument ; and the extracting 

 of it will become much more easy by the means of these forceps, than by the 

 bullet-drawers, and most of the other instruments invented for that purpose. 



