214 Brande on the Medico-Chemical 



prevent the formation of red sand; his sufferings increased, 

 and upon admission to the hospital he passed large quantities 

 of uric and fusible sand mixed with ropy mucus. 



The history of this case naturally led to the inference, that 

 the stone would be found to consist of an uric nucleus enve- 

 loped in the phosphates, and upon making a section of it, (it 

 was the size of a small hen's egg, somewhat flattened,) a kidney 

 calculus of uric acid was perfectly distinct in its centre, sur- 

 rounded by a less compact deposition of the same substance ; 

 exterior to this was a layer of the mixed phosphates, (fusible) 

 and the outer crust was an intimate mixture of the phosphates 

 and uric acid ; so that these successive deposits presented a 

 sufficiently distinct epitome of the case. 



Other cases to the same point, and equally illustrative, are 

 detailed in Sir Everard Home's observations on calculi, annexed 

 to my paper, communicated to the Royal Society in 1808 (Phil. 

 Trans. 1808.J, and where uric acid and the phosphates only 

 are concerned, it is in general not difficult, from a consideration 

 of the history of the case, to predict the nature of the calculus. 



Where the calculus is of oxalate of lime, or of cystic oxide, 

 the prognostics are by no means so decided ; in the former, it 

 generally, I think, happens, that there is little or no sand or 

 gravel voided, and that we hear of the symptoms of the stone 

 of the bladder following those of the passage of a calculus along 

 the ureter, but unattended by that production of uric acid and 

 of the phosphates, which prevails in the former cases. I can 

 only cite one instance of the extraction of a mulberry calculus by 

 operation, in which some account of the previous symptoms 

 was obtained. The man was 62 years of age, and about five 

 years previously had suffered a slight attack of the symptoms 

 of a stone passing from the kidney to the bladder ; he had voided 

 no sand, and his urine always appeared clear ; during the last 

 two years the symptoms of stone in the bladder attained such 

 violence as to render the operation necessary, and a very per- 

 fectly-formed mulberry calculus, about^ the size of a nutmeg, 

 with a distinct oxalate of lime nucleus was removed. 



Of the history of cystic oxide, as relating to the present in- 



