GENERAL OBSERVATIONS. 471 



Now, although the number of subsalts which 

 I have examined is exceedingly small, because 

 my object was not to investigate the truth of 

 Berzelius' law, but to determine the quantity of 

 water of crystallization which the salts contain, 

 yet there occur several which are inconsistent 

 with Berzelius' law. This is the case, for ex- 

 ample, with the disulphate of alumina, the atoms 

 of oxygen in the base being 2, and those in the 

 acid 3. The following subsalts are precisely in 

 the same predicament : 



ATOMS OF OXYGEN IX BASE DITTO IX Atltt. 



Dinitrate of alumina . 2 5 



Trisnitrate of alumina . 3 5 



Diprotarseniate of iron .2 3 



Dinitrate of lead . 2 5 



Diacetate of lead . . 2 3 



Diacetate of copper (verdigris) 2 3 



Dinitrate of bismuth 2 5 



These examples comprehend not only nitric acid, 

 which Berzelius has recognised as an exception 

 to his law ; but likewise, sulphuric acid, arsenic 

 acid, and acetic acid. 



It would certainly be a most remarkable cir- 

 cumstance if 2 atoms of any protoxide were in- 

 capable of combining with 1 atom of any of the 

 13 acids in the preceding list. I have given 

 seven examples of such combinations ; and am 

 persuaded that many more will be discovered 



G g -1 



