Tantalum or Columbium

As described in Chapter 22 Niobium, Hatchett found a new element in 1801 that he called columbium. The disputes about whether columbium and tantalum were two names for one and the same element or if they really were two different metals have 

It is not known how Ekeberg reacted to the situation when the tantalum/niobium discoveries attracted international interest within chemistry. Perhaps he suffered the torments of Tantalus, when his priority in the discovery of tantalum was questioned 

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The similarity shown by Hatchett s columbium and Elceberg s tanta lum attracted attention, and in 1809 Wollaston attempted to prove that the two elements were identical. He prepared a list of similar properties shown by the acids of the elements, and claimed that the greatest difference was the specific gravity of the minerals — tantalite having a specific gravity of 7.95 and columbite 5.91. This difference he explained as due either to different conditions of oxidation or to different states of molecular strum ture. His deductions were accepted, and for many years the " element was called either tantalum or columbium. 

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