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considerable solvent powers upon these animal concretions, 

 contrary to what has been hitherto supposed. 



EXPERIMENT XIV. 



Into a filtered solution of ten grains of salt of tartar, 

 in four ounces of distilled water, were introduced two fras:- 

 ments of calculi, weighing seventy-four grains and a quar- 

 ter. The mixture was set aside for forty-eight hours in 

 a cool room; temperature varying, from 47 degrees at night, 

 to 53 degrees in the day. After twelve hours it began to 

 be coloured, and continued to be more so, until the tem- 

 perature fell to 51 degrees, when a precipitation took 

 place, and continued during the night; so that it appear- 

 ed to deposit, at the temperature of 47 degrees, what Avas 

 taken up at degrees somewhat exceeding 51°. These frag- 

 ments, on being taken out, dried, and weighed, were found 

 to have lost three grains and three quarters; the lamina; 

 disposed to crack, and the strata to separate and crumble. 

 This weak lixivium, then, exerted much energy, even in a 

 very low temperature. 



EXPERIMENT XV. 



A fragment of calculus, Aveighing seventeen grains three 

 quarters, was immersed in a lixivium of similar strength; 

 but noAV exposed to a temperature, varying, from 51 de- 

 grees at night, to about 95 degrees in the day. After 



p p 2 forty- 



