GENERAL OBSERVATIONS. 



whenever the attention of chemists is particular- 

 ly turned to the subsalts. 



There is another kind of saline combination 

 in which exceptions to the law of Berzelius may 

 also be looked for ; I mean those salts which I 

 have distinguished by the epithet sesquisalts or 

 subsesquisalts. In the sesquisalts, 1| atom of 

 acid unite with 1 atom of base ; or, which comes 

 to the same thing, 3 atoms of acid unite with 

 2 atoms of base. In the subsesquisalts, li atom 

 of the base unite with 1 atom of the acid ; for 

 example, the sesquicolnmbate of barytes is com- 

 posed of 



3 atoms columbic acid, containing .'? atoms oxygen. 

 2 atoms barytes - 2 -- 



Here we see, that the oxygen of the acid is not 

 a multiple of that in the base. 



When the acid contains 2 atoms of oxygen, 

 and the base 1 atom, it is plain that the sesqui- 

 salts must all come under Berzelius' law ; be- 

 cause 1<] atom of acid will contain 3 atoms of 

 oxygen, and 3 is, of course, a multiple of I ; but 

 in acids containing 1 or 3 atoms of oxygen, the 

 law of Berzelius cannot hold. 



With respect to the subsesquisalts they will 

 all come under Berzelius' law when the acid 

 happens to contain 3 atoms oxygen, and the base 

 only 1 atom ; but they will deviate from it when- 

 ever the acid contains 1 or 2 atoms of oxygen. 



