296 



forty-eight hours, it was found to lose five grains and a 

 half: a prodigious quantity, when we consider the small 

 surface presented by this fragment, weighing only seven- 

 teen grains three quarters. The solution, upon cooling, 

 became turbid, as before, and precipitated a large pro- 

 portion of the dissolved uric acid. 



EXPEKIMENT XVI. 



A fragment of calculus, weighing forty grains three quar- 

 ters, was immersed in four ounces of soda water for forty- 

 eight hours, and exposed to a temperature, varying from 

 55 to about 100 degrees. Its loss amounted to one grain. 

 A repetition of this experiment aifor<ied nearly the same 

 result; and demonstrates, that though the soda, in this su- 

 per-carbonated state, still exerts some energy, on concre- 

 tions of the viric acid kind, yet it is but feeble; and that 

 these waters appear more capable of preventing their for- 

 mation, than eifecting their solution, when they once ac- 

 quire the aggregate state. The same fragment, in a simi- 

 lar quantity of soda Avater, in the temperature of from 50 

 to 55 degrees only, sustained no loss, after forty-eight 

 hours. And here we have another proof of the necessity 

 of seriously attending to the degree of temperature, in all 

 researches of this kind. i 



But it may be observed, as to the internal use of alka- 

 line substances in particular, that their effects must be 

 considerably weakened, upon their immediate admixture 



with 



