PHYSICAL AND LITERARY. 339 



is dilated with an equal quantity of 

 diftilled water, it will continue clear 

 and lympid, without any precipita- 

 tion: If then a piece of poiiflied cop- 

 per is put into the folution, the liiver 

 falls gradually down, and the copper is 

 diflblved, as appears by the green colour 

 which the liquor acquires in a little time. 

 When the filver is all feparated, take out 

 the remaining copper, and put in a piece 

 of clean iron j the green colour goes gra- 

 dually off, by the copper falling down, 

 and the iron is difTolved in its place: Af- 

 ter allowing a fufficient time for the folu- 

 tion of the iron, and precipitation of the 

 copper, put into the folution a piece of 

 li^e-ftone; the aqua forth immediately 

 works upon it with frefh vigour: Laflly, 

 add ibme fait of tartar^ or oUuni tartaric 

 p. d. ; this precipitates the flony matter, 

 and renews the effervefcence. This feen^s 

 to finifh the work, and quite to abforb 

 the acid, and deftroy all its folvent 

 powers: Yet even here the acid only lurks 

 and conceals itfelf by its ftric^ union 



with 



