URINARY CALCULI. 



the kidney lofcs nt lad all vefliges of its natural ilrufture, 

 and is converted into a kind ot cyil, tiUed with the ex- 

 traneous fubftancc. As Dr. Marrct obferves, when fuch a 

 complete alteration of ftrufture takes place, the fecrction 

 of urine muft of courfe be entirely carried on by the other 

 kidney. This, however, in fome inftances, is attended 

 with fo little inconvenience as almoft to cfcape notice ; and 

 it fometimes even happens, that both kidneys are difeafed in 

 a very great degree, and yet life is preferved for a confidcr- 

 able time. Op. cit. p. 3, 4. 



Calculi are fometimes found in the ureters, cfpecially 

 at their upper part ; but it is not fuppofed that they are 

 in general originally formed in that lituation ; an event 

 not likely to happen, unlefs there be fome caufe ob- 

 llrudling or retarding the defcent of the urine through thofe 

 tubes. The common belief is, that all calculi found in the 

 ureters are firft produced in the kidneys, from which they 

 afterwards defcend in <he courfe of the urine. 



The generality of calculi, however, which leave the kid- 

 ney, are of fmall fize, and confequently, after a time, and 

 exciting fome paui and inconvenience, they ufually get into 

 the cavity of the bladder. Indeed, as Dr. Marcet remarks, 

 the bladder is the moil frequent feat of calculi, not only 

 becaufe all urinary concretions, or their nuclei, formed 

 in the kidneys tend to fall into that organ, but alfo becaufe 

 a Hone may be, and probably often is, originally formed in 

 the bladder itfelf. 



It is, however, in the infundjbula and pelvis of the kid- 

 ney, that the firft nuclei of urinary calculi are commonly 

 produced. Renal concretions vary confiderably in their 

 number, fize, and fhape. In fome cafes, a fingle fmall cal- 

 culus has been found occupying one of the foregoing fitua- 

 tions ; while, in other inftances, an innumerable coUeftiou 

 ot calculous fubftaiices are obferved filling the whole of the 

 cavity of the pelvis and infundibula of the kidney, diitend- 

 ing its parietes, and even obftrufting the paffage of the urine 

 out of this vifcus, which is converted into a fort of mem- 

 branous cyil. Laftly, a fingle ftone in the kidney may ac- 

 quire a very large fize there ; or a great number of fmall 

 calculi, in the fame fituation, may become cemented toge- 

 ther by the depofition of frefh concreting matter between 

 them, fo as to form one mafs of enormous dimenfions, and 

 the fhape of which invariably correfponds to the fpace in 

 which it is, as it were, moulded. Hence it is, that renal 

 calculi often prefent a variety of odd irregular figures, re- 

 fembling thofe commonly obferved in fpecimens of coral. 



We have already remarked, that urinary concretions of 

 large fize very often exiil in the kidney, without their pre- 

 fence being indicated by any external circumilances, or at- 

 tended with any fymptoms, fufliciently unequivocal to con- 

 ftitute a ground for fufpefling the importance of their caufe. 

 On the other hand, it is very ufual for renal calculi, of m.id- 

 dling dimenfions, to excite ferious and alarming complaints. 

 The reafon of this difference becomes obvious, when it is 

 recollefted that fmallilli concretions are rcadilv carried with 

 the urine into the ureter, and become fixed in the narrow 

 portion of the tube. But very large calculi can be contained 

 only in the upper part of this canal, where its parietes arc 

 more yielduig, and the fpace in them more capacious. 



Calculi of middling fize, in tlieir paffage through the 

 ureter, caufe, at firft, a feeling of heavinels, or an indeter- 

 minate fenfe of uneafinefs, and an obtufe pain in the region 

 of the correfponding kidney. Thefc complaints occur at 

 intervals of greater or Icfs duration. At length, the pain 

 grows more urgent and annoying, attended « itli flatulence, 

 heartburn, frequent vomiting, painful letraftion of the lef- 

 ticlc, and fometimes acute fever. The patient makes water 

 6 



frequently, and in fmall quantities at a time ; and the urine 

 is high-coloured and bloody. The patient cannot fit upright, 

 his body being bent forwards towards the afl'efted fide. 

 Thcfe fymptoms may have more or lefs duration, and then 

 fuddenly ceafe. They may alfo fubfide and recur feveral 

 times fuccelFively, v^-ith intervals of fome days. In the latter 

 cafe, the pain is felt at each attack to be fituated lower in 

 the track of the ureter. Laftly, when the fymptoms havt 

 entirely difappcared, the urine is more abundant, not fo high 

 coloured, and eafily difcharged, tlie ftream fometimes bring- 

 ing out with it the urinary concretion, which has now en- 

 tered the bladder. 



Suppuration of the kidney, and an abfcefs in the lumbar 

 region, in confequence of renal calculi, are not very common 

 events. This, however, is the only cafe of the kind, in 

 which the interpofition of furgery can be ufeful. By ad- 

 verting to previous circumftances, and the irregularity of the 

 pain about the kidney, the praAitioncr may fufpcft the 

 nature of a phlegmonous tumour in the fituation of this 

 vifcus. Whatever may be his conjcftures, however, he muft 

 carefully abftain from the ufe of liis lancet, until purulent 

 matter is obvioufly under the integuments. He may then 

 fafely make an opening, from which urine and pus will be 

 difcharged, and through which the calculi themfelves may 

 fometimes be felt and extrafted. If they ftiould not be 

 readily touched with a probe, let not the furgeon raftily con- 

 ceive, that he is juftified in endeavouring to difcover them 

 with his knife. Their fituation may be fuch as to bafRe aU 

 his endeavours, and the operation itfelf might caufe a moft 

 dangerous hemorrhage, and other fatal mifchief. The open- 

 ing of an abfcefs of the kidney may remain a long while fif- 

 tulous, and the circumftance may indeed warrant the con- 

 clufion, that the healing is prevented by the prefence of fome 

 extraneous fubftances ; but a prudent praftitioner will never 

 think of performing any operation for their extraction, be- 

 fore nature has brought them tolerably near to the furface. 



Urinary calculi, which form upon foreign bodies acciden- 

 tally introduced into the bladder, and afting as nuclei, are 

 always fingle, unlefs the number of foreign bodies themfelves 

 happen to be greater. It is curious alfo to find, from the ob- 

 fervations of Dr. Marcet, that, in fuch inftances, the depofi- 

 tion moft frequently, if not always, coiififts of the earthy phof- 

 phates, and cfpecially of the fufible calculus. But when 

 calculi originate from a particular diathefis, there may be 

 many of them lodged in the bladder at the fame time. Seve- 

 ral diftindl nuclei may defcend fucceffively from the kidneys, 

 and each may increafe in a feparate manner. Sometimes, 

 however, calculi in the bladder, which were at firll diilinft 

 and unconnefted, become afterwards cemented together, fo 

 as to make only one mafs. 



The magnitude of calculi in the bladder is generally in an 

 inverfe ratio to their number. Some hundreds have been 

 found in one bladder, but they were not larger than a pea. 

 Others of fo large a fize have been met with, that ttiey were 

 more than fix inches in diameter. In Fourcroy's mufeum, 

 and in that of the F.cnle de Mcdccine at Paris, may be feen 

 fome calculi which filled the whole cavity of the bladder ; 

 and in the Phil. Tranf. for 1809, the late fir James Earle 

 has dcfcribed an enormous llone, which he extraded after 

 death from the bladder of a gentleman who had been unfnc- 

 cefsfuUy cut for it. Tliis calculus weighed three pounds four 

 ounces, and was of an oval Ihajie, its long axis mcaluring fix- 

 teen inches. It was of the fulible kind. Their aver,ige fize 

 may be compared with that of a chefnut, a walnut, or a 

 fmall hen's egg. Their weight differs from a few grains to 

 upwards of fifty ounces. Conunon ilones of the bl.idder, 

 however, weigh from two to fi.\ ounces. Their weight is 



not 



