OBSERVATIONS ON 



pitation with fncclmrinc acid proved to begypfe- 

 ous. In a diluted folution of a calculous matter, 

 no change was at firft obferved ; but after a conii- 

 derable part of the inniihirc was evaporated, try. 

 flals began to appear. Kroin thefe circumilanccs 

 if appears, that there is actually quick-lime in 

 urinary calculi; but in a very finall proportion, 

 as one hundred weight fcarce everallords more 

 than halfa pound. 



Strong vitriolic acid diflblves calculous mat- 

 ter, with the help of heat, and with ellervd"- 

 cence. The folution is of a black colour ; and 

 if a little water be poured into it, fcems in foine 

 degree to coagulate; but on the addition of a, 

 larger quantity of water, recovers its limpidity, 

 and afliuncs a brown colour. 



Muriatic acid feems to be incapable of difiol- 

 ving calculous matter; yet, I know not but it 

 may feparate a part of the lime. 



The rcihicfs which fometiincs arifcsin the ni- 

 trous folution of calculous matter is remarkable. 

 When the folution is faturated, it gives no indi- 

 cation of the prcience of the nitrous acid by its 

 fin ell ; and when evaporated in a large open vef- 

 fel, it is changed into a darkened liquor, in which 

 tinfture of turnfolc can fcarce dctcft any re- 

 mains of nitrous acid. Any acid deftroys the 

 redncfs; and neither the infufion of alkali, nor 

 any other addition can re do re it. If the moi- 

 ihire be more fpeedily evaporated, the folution 



fwclh 



