On Gravelly and Calculous Concretions. ^3 1 



Experiment X. 



To three ounces of urine, in a well closed phial, was added 

 half an ounce of the aqua mephitica alkalina, prepared ac- 

 cording to Dr. Faulkner's proportions. No crystallized ap- 

 pearance after seven days. This result we might well ex- 

 pect, from the relative large proportion of its alkaline salt ; 

 having already seen equally good effects, from half an ounce 

 only of Kinsley's soda water, containing a mere fraction of 

 alkaline matter. 



Experiment XI. 



To three ounces of urine were added two grains of the 

 common salt of tartar of the shops, containing, according 

 to ISIr. Kirwan, 0*82 of alkali. The same results as in the 

 former experiments, even after six days. 



Experiment XI L 



Having no pure mineral alkali, three grains of the com- 

 mon crystallized soda of the shops, containing, according to 

 Mr. Kirwan, 0-64 of alkali, were added to four ounces of 

 urine. The result as in the former ; which was equally pro- 

 duced by two grains only; and perhaps would have been 

 equally so by one. 



Wishing to be more fully convinced that the very large 

 proportion of disengaged carbonic acid gas in our soda wa- 

 ters did not counteract the usual alkaline effects : 



Experime7it XIII. 



To four ounces of the urine of the same child, which v.a> 

 generally surcharged with gravelly matter, I added half an 

 ounce of Kinsley's soda water in its full state of efferves- 

 cence : the phial well corked, and removed into a cold cellar, 

 temperature 42 degrees. After four days, nay, a week, no- 

 thing but the usual calcareous sediment, without an atom of 

 crystallized, or otherwise precipitated uric acid. 



From the above experiments, then, we learn, that pure 

 lime in the state of lime water, the pure alkalies, the sub- 

 carbonated, carbonated, and super-carbonated, all prevent 

 ihe separation of the uric acid, by uniting probably with, 



and 



