3S On Gravelly and Calculous Concretions. 



by the small, silky, needle-shaped, crystalline appearance 

 peculiar to the uric acid. 



Experiment VIIT. 

 This same fragment of calculus, after being well washed, 

 and dried, was again immersed, for forty-eight hours, in a 

 lixivium consiating of only twenty drops of aijua kali puri 

 to four ounces of distilled water, and under the same cir- 

 cumstances. Upon being taken out, and dried, it was 

 found to have lost four grains and a quarter. The solution 

 was of a yellowish green colour, lost all alkaline taste, and 

 precipitated, as before, with either the acetous or muriatic 

 acid. 



Erperi)nenf IX. 



A fragment of calculus, of the same kind, weighing 

 eighty-one grains, was suspended, as before, for forty-eight 

 hours, in a mixture consisting only of fifteen drops of the 

 same alkali to four ounces of distilled water, which scarcely 

 imparted an alkaline taste. After being taken out, and dried, 

 it was found to have lost one grain and three quarters ; the 

 specimen consisting chiefly of the external laminae, much 

 more slowly acted upon. 



Experiment X. 

 This same fragment, washed and dried, was agaim im- 

 mersed, for forty-eight hours, in a similar lixivium, and 

 under the like circumstances. TTie loss now amounted to 

 nearly four grains ; and from this we learn how considerably 

 the energy of the menstruum is increased bv each succeeding 

 immersion ; so much so, indeed, that a few repetitions en- 

 able it to disunite the laminae, and cause them to crumble 

 into a pulverulent state, easily voidable with the urine. To 

 the happy result, therefore, of this experiment let me ear- 

 nestly solicit the attention of our young practitioners. 



[To be continued.] 



V. The 



