Brande on Calculous Disorders. 67 



The calculi formed in the kidney, and voided without re- 

 maining any considerable time in the urinary passages, are 

 either uric, oxaHc, or cystic. It is difficult to assign a reason 

 why the phosphates never concrete so as to form small kidney 

 calculi : but I have never as yet seen an instance of this kind ; 

 for in three instances in which concretions, consisting of am- 

 monio-magnesian phosphate were voided, they were solely of 

 bladder origin, and appeared to owe their formation to disease 

 of the prostate gland in two cases ; and in a third were frag- 

 ments of a larger calculus rounded by attrition in the bladder. 



The uric calculi, as voided immediately from the kidney, are 

 of a yellowish or reddish brown colour, somewhat hard, soluble 

 in caustic potash, exhale the smell of burned horn before the 

 blowpipe, and when heated with nitric acid, produce the pecu- 

 liar red compound which Dr. Prout has called rosacic acid. 



The oxalic calculi vary considerably in appearance. They 

 are generally of a greyish brown colour, and made up of nu- 

 merous small cohering spherules : sometimes they have a po- 

 lished surface, and resemble a hempseed. They are easily re- 

 cognised by their insolubility in dilute muriatic acid ; and by 

 their behaviour under the blowpipe, where they swell up, and 

 burn into a white ash, consisting of pure lime. 



The cystic calculi have a yellowish colour, a crystallized ap- 

 pearance, and are soluble in dilute muriatic acid, and in diluted 

 solution of potash. When heated in the flame of a spirit lamp, 

 or by the blowpipe, they exhale a peculiar fetid smell, which, as 

 Dr. Wollaston has remarked, is singularly characteristic of this 

 species. 



With respect to the relative frequency of these calculi, the 

 first are by far the most common ; the second are not rare, and 

 the third of unfrequent occurrence. Out of 58 cases of kidney 

 calculi, 51 were uric, 6 oxalic, and 1 cystic. 



The treatment of kidney calculi may be divided into general 

 and particular. The former applicable in all cases ; the latter 

 dependant upon the chemical nature of the concretion. 



As a full and nutritious diet, and the daily use of fermented 

 liquors, tend, independent of other causes, to increase the 

 F 2 



