45 
mineral columbite from Massachusetts, and to this he gave 
the name of Columbium. Ekeberg a year later found a 
similar new metal in a rare Swedish mineral, and to it he 
gave the name Tantalum. Wollaston in 1809 came to the 
conclusion that these two metals were identical. Berzelius 
next examined the metal contained in the Swedish tanta- 
lite, and afterwards Wohler found these metals in several 
other minerals. Heinrich Rose next investigated this sub- 
ject, but in spite of persistent effort the results of his 
experiments left the matter in a still less satisfactory con- 
dition, inasmuch as he first came to the conclusion that two 
more new metals were contained in these minerals, to which 
he gave the names of Niobium and Pelopium, whilst at a 
later period he decided that both niobic and pelopic acids 
were different oxides of the same metal, for which he pro- 
posed the names niobic and hyponiobic acids. 
Then again in 1860 v. Robell thought that he had found 
a fourth new metal, which he called Dianium, in the 
the same minerals, and Hermann believed that he had dis- 
covered in them a fifth metal, to which he gave the name 
Ilmenium. It is to Marignac and Bloomstrand that we owe 
a deliverance from this state of contradiction and uncer- 
tainty. They independently proved that only two metals 
in reality exist — Niobium and Tantalum — and that these 
are present in varying proportion in most of the minerals 
in question. They showed that the compounds derived 
from Rose’s niobic oxide contain mixtures of niobic and 
tantalic oxides, whilst his hyponiobic oxide is pure niobic 
oxide. 
Bloomstrand arrived at this result by a series of analyses 
of the chlorides. He proved that the white hyponiobic 
chloride of Rose is in fact an oxychloride, whilst the yellow 
niobic chloride contains no oxygen. 
Marignac, on the other hand, came to a similar conclusion 
by an investigation of the fluorides of niobium and tanta- 
lum, and pointed out that the oxides are pentoxides Nb 2 0 5 
