S+20=S0 2 . S0. 2 +OH a =S0 3 H a . 

 S0 3 H 2 +0=S0 4 H 2 . 



Dolomites 2(C0 3 )CaMg. 

 2(CO,)Ca.Mg+2S0 4 H a =S0 4 Ca+S0 4 Mg+20H a + 



[2CO a . 



This reaction finds marked illustration in towns 

 where dolomitic building-stones, & bituminous coal- 

 fuel, are used. (e. g. Parliament Houses.) 





