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weighed and dried, both before and after immersion in their 

 several menstrua. 



Dr. Percival, of Manchester, as well as others, having 

 experienced the solvent power of the plain mephitic, or 

 carbonated water, on urinary calculi, it was thought proper 

 to repeat his experiments. 



EXPERIMENT I. 



A fragment of a calculus, weighing twenty-three grains, 

 and of the uric acid kind, was suspended by a thread, for 

 forty-eight hours, in Nooth's apparatus, already nearly filled 

 with highly impregnated aerated water, and still exposed 

 to a stream of carbonic acid gas : temperature 58 degrees. 

 When taken out, and dried, weighed, as before, twenty- 



three grams. 



EXPERIMENT It. 



A fragment of a calculus, of the same kind, weighing 

 forty grains and three quarters, was suspended, as before, 

 in Nooth's apparatus, for forty-eight hours: temperature 

 varying from forty to fifty-five degrees. On being taken 

 out, and dried, was found to have sustained no loss. 



EXPERIMENT III. 



An entire calculus, of a rough and sandy appearance, 



chiefly of the uric acid kind, but with some extremely 



VOL. X. o o minute 



