OF THE ATOMIC THEORY. 45 



soda, possesses alkaline characters. We cannot, 

 therefore, determine the proportion between the 

 atoms of acid and base in the borates, by their neu- 

 trality. The same thing holds with the alkaline car- 

 bonates, which always possess alkaline properties 

 whatever be the number of atoms of carbonic 

 acid they contain. On the other hand, there are 

 several bases, as the oxides of copper and zinc, 

 which do not destroy the acid properties of acids 

 in how great a proportion soever they be combined 

 with them. Such salts alway redden vegetable 

 blues, and possess certain characters denoting the 

 presence of an acid. 



(3.) The weights of certain acidifiable bases 

 were determined by their relation to oxygen. 

 Thus it was found that 2 of sulphur is capable of 

 combining with 1, 2, and 3 of oxygen. Hence, it 

 was concluded, that 2 represents the atomic 

 weight of sulphur, and that the atomic weights 

 of the compounds of sulphur and oxygen are, 



ATOMIC WEIGHT. 



1. 2 sulphur + 1 oxygen = 3 hyposulphurous acid. 



2. 2 +2 = 4 sulphurous acid. 



3. 2 +3 =5 sulphuric acid. 



In like manner, O75 carbon unites with 1 and 2 

 of oxygen. Hence 0*75 represents an atom of 

 carbon, and the atomic weights of the com- 

 pounds of carbon and oxygen are, 



1. 0-75 carbon + ] oxygen = 1'75 carbonic oxide. 



2. -f 2 = 2-75 carbonic acid. 



