291 



OiXPERIMENT XJ. 



As children are such frequent sufferers, Mr. Richards 

 suggested the propriety of ascertaining, Ayhether the alka- 

 line influence might be weakened, by the addition of su- 

 gar. One half of a calculus, of the uric acid kind, weigh- 

 ing 185i grains, extracted by my friend Mr. Richard Dease, 

 and (though under the most unpromising circumstances) 

 with a dexterity and success, not to be exceeded by 

 his late father, Avas suspended in a lixivium, consisting of 

 eight ounces of distilled water, and twenty drops of weak 

 aqua kali purl (partly a^erated), and scarce imparting an 

 alkaline taste. To this were added, thirty-six grains of su- 

 gar, which were found adequate to sweeten it sufficiently. 

 After remaining forty-eight hours, in a temperature, vary- 

 ing from 55 to near 100 degrees, or a medium one of 74°, 

 being dried and Aveighed, it was found to lose ten grains 

 three quarters. The addition, then, of saccharine matter 

 cannot diipinish, but may add to the alkaline energy. 



EXPERIMENT XI.I. 



Ten grains of very pure crystallized carbonate of potash 

 were dissolved in four ounces of d-istiUed water. In this 

 filtered lixivium was suspended a fragment of calculus, of 

 the uric acid kind, weighing seventy-two grains and a quar- 

 ter, for forty-eight hours, on a sand heat, varying from 50 



to 



