COLUMBIUM. 79 



paper purple, it is clear that it can contain only 

 1 atom of columbic acid at the very utmost ; Atom of 

 consequently, 19 must represent the atomic ^!d. mb 

 weight of columbic acid. 

 5. I found the hydrate of columbic acid form- Hydrate of 



columbic 



ed, by drying the precipitated acid in the open acid, 

 air, a compound of 



1 atom columbic acid 

 7 atoms water 



26-875 



Berzelius seems to have obtained a hydrate, con- 

 taining a much smaller proportion of water. Pro- 

 bably it had been dried in a much higher tem- 

 perature than mine. 



6. Berzelius could form only one oxide of 

 lumbium, namely, columbic acid. He informs 

 us, that, when 100 parts of columbic acid were tal * 

 reduced to the metallic state, the metallic tan- 

 tulum formed weighed 94*8. Now, if the quan- 

 tity of metal had been 94*737 > instead of 94'8, 

 it would have exactly corresponded with the 

 atomic weight of columbic acid as above deter- 

 mined ; for, 



5-263 (ihe oxygen in the acid) : 94-737 (the quantity of 

 base in it) : : 1 : 18. 



Thus it appears, that Berzelius' analysis of the 



16 



