33S CALCULI. 



Experiments Exp. 9. The result of the above experiments having led 



honsonuruje *^ some doubt, as to the good eflects of tlie carbonic acid 



*-e . gas, so much, at one time, recommended by Doctors 



Percival and Satmders, previous to its more modern alkaline 



combination, in our mcphitic, as well as super-aerated 



soda waters. 



Into the middle part of Nooth's apparatus, were intro- 

 duced four pounds of fresh rendered healthy urine, and.; 

 exposed to a stream of carbonic acid gas. After a few- 

 hours, a copious and beautiful precipitation of uric crys-j 

 tals took place, (notwithstanding the constant agitation,, 

 from the transmission of the gazeous bubbles,) larger than> 

 any I before observed, that from the tartarous acid ex- 

 cepted. In a standard quantity, no distinct crystalliza- 

 tion, even after two days. A repetition of the same ex- 

 periment afforded similar results. 



Exp. 10. Finding th<i carbonic acid gas productive of 

 similar effects, with the other acids hitherto examined; it 

 was natural to inquire, hovv far its combination with the 

 portion of alkaline matter, contained in our mephitic and 

 soda waters, so highly surcharged with it, may prevent a 

 separation of this uric acid. 



Half an ounce only, of the common soda water of the 

 shops, prepared by Mr. Kinsley, was added to four ounces 

 of healthy urine. A similar quantity was impregnated 

 with carbonic acid gas. In the former, after forty-eight 

 hours, or more, no more than the usual nubecula: nor 

 could a single crystal be discovered, even by a magnifier. 

 In the latter, an early, copious, and beautiful crystalliza. 

 tion. On the result of this experiment, frequently re- 

 peated, with various proportions of the mephitic alkaline 

 water, I shall _after wards have occasion to make some 

 remarks. 



Though the mineral acids, in an uncombined state, en- 

 ter not into the matter of our diet, and are no longer 

 ctjhsidered as lithontriplics, since the notion of the earthy 

 nature of these concretions has been abandoned ; yet, as 

 they are sometimes prescribed with other indications, I 

 thought fit to extend my researches (though in a summary 

 way) to tht^m also. 



Exp. 



