MERCURY. 425 



now analyze the conversion of 27 grains of per- 

 oxide of mercury into 34 grains of corrosive sub- 

 limate. 



27 peroxide are composed of 



Mercury . 25 



Oxygen . 2 



27 



When muriatic acid is poured upon the 27 per- 

 oxide, two atoms of the acid, equivalent to 9 '25 

 grains, unite with the oxide, forming a com- 

 pound, which will amount to 36'25 grains, and 

 be a compound of 



1 atom peroxide 27 



2 atoms muriatic acid 9*25 



36-25 



When the solution is evaporated to dryness, the 

 acid and peroxide mutually act upon each other : 

 the oxygen of the oxide combines with the hy- 

 drogen of the acid, constituting 2 atoms of wa- 

 ter, which are expelled by the heat ; while the 

 2 atoms of chlorine combine with the 1 atom of 

 mercury, and form a perchloride. Thus by the 

 heat, the 36-25 of permuriate of mercury is re- 

 solved into 



Oxygen 2 \ 



> constituting two atoms water. 

 Hydrogen 0-25 j 



2-25 



