tOL. XLVI.] PHILOSOPHICAL TRANSACTIONS. 027 



Mr. M. enters not into a strict examination of those fatal symptoms which some- 

 times succeed the operation in grown subjects, in order to prove that they in 

 general proceed from the bladder's being too roughly dealt with, because the case 

 is of itself very evident; unless the habit be remarkably bad, to what else shall 

 we attribute violent pain, and the successive inflammation, tumour, suppression 

 of urine, mortification, &c. ? These surely are not the attendants on a simple 

 incision only; for constant experience evinces, that the bladder, though an organ 

 of great importance, and essentially necessary to the animal economy, may be 

 wounded with as little danger of any of the above-mentioned evils, as any other 

 membranous part. 



But probably we should not be at a loss for the true cause of all those mis- 

 chiefs, if the state of the parts in the extraction of a large stone be closely con- 

 sidered. It may be observed, when a stone is laid hold of by the forceps, that 

 both together, stone and forceps, from the screw-pin to the former, form a com- 

 plete wedge ; insomuch that a person in a forcible extraction, can hardly conceive 

 the power applied to the bladder, or the force with which it is distended. If the 

 diameter of the stone be equal to a third part of the length of the chops of the 

 forceps, a force of 10 lb. applied to them, will be to the wound of the bladder as 

 30: but how shocking must be the case, when, either on account of the mag- 

 nitude of the stone, or narrowness of the wound, a man uses his utmost force, 

 and many such instances in adult bodies occur. The power is then augmenteci 

 by the action of the lever to 1 or 300, a force no doubt sufficient to rend the 

 bladder and neighbouring parts to rags. And there is too much reason to be- 

 lieve, that the want of success in subjects arrived at adult age, where the stones 

 are almost always large, is owing intirely to this very circumstance. 



When all this violence is insufficient, there is at present no other established 

 method, but either to attempt the making a second incision on the stone, as it 

 is held in the forceps, or to withdraw the latter, and to make it on the bladder, 

 in the flaccid state as it then lies, without any guide at all. As to the first me- 

 thod, it is evident that the forceps, stone, and bladder in men, are so much in 

 the dark, that the incision must be made with the utmost difficulty; indeed it is 

 hardly possible to cut at all with any certainty. And the other way of cutting 

 on the bladder, when the forceps is withdrawn, is much worse; for if it be 

 remembered, that the bladder lies upon, and is contiguous with the rectum, and 

 that they are both in the same flabby state, it will appear almost impossible to 

 cut the one, without wounding the other. 



This manifest defect in the operation would be intirely removed, if there always 

 was a director for the knife left in the bladder; and this is so easily and com- 

 pletely to be done, that its great simplicity seems to be the reason it has not been 

 attended to. If one limb gf the forceps, from the joint to its extremity, be 



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