LIME AND CALCIUM. 



which they cannot be completely deprived, with- 

 out the risk of losing at the same time a portion 

 of their acid. On this account, the method 

 which I was obliged to employ in determining 

 the atomic weight of lime, was rather more com- 

 plicated than that which gave the atomic weights 

 of the other alkaline bodies contained in this 

 chapter ; though it was equally decisive. 



1. 6*25 grains of pure calcareous spar (kept 

 for twenty-four hours at a temperature higher lime deter. 

 than that of boiling water) were dissolved in 

 muriatic acid, and the solution evaporated to 

 dryness in a low temperature, in order to get 

 rid of all excess of acid. The muriate of lime, 

 thus rendered neutral, was re-dissolved in a 

 small quantity of distilled water. In another 

 portion of distilled water I dissolved 8 *75 grains 

 of pure anhydrous carbonate of potash. These 

 two solutions being mixed, a double decomposi- 

 tion took place, the lime and carbonic acid 

 precipitated in the state of carbonate of lime, 

 while the muriatic acid and potash remained in 

 solution in the state of muriate of potash. 



The clear liquid remaining after the precipita- 

 tion of the carbonate of lime, produced no 

 change in the colour of cudbear pape and con- 

 sequently contained no sensible quantity of 

 carbonate of potash ; and as it was not precipi- 

 tated by oxalate of ammonia, it contained no 

 sensible quantity of lime. 



S 2 



