AND A NEW NIOBIUM CHLORIDE. 187 



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 

 proposed the names niobic and hyponiobic acids. 



Then, again, in i860, v. Kobell thought that he had found 

 a fourth new metal, which he called Dianium, in the same 

 minerals; and Hermann believed that he had discovered 

 in them a fifth metal, to which he gave the name of Ilme- 

 nium. It is to Marignac and Bloomstrand that we owe a 

 deliverence from this state of contradiction and uncertainty. 

 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 Rosens 

 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 E-ose is, in fact, an oxychloride, whilst the 

 yellow niobic chloride contains no oxygen. 



Marignac, on the other hand, came to a similar conclu- 

 sion by an investigation of the fluorides of niobium and 

 tantalum, and pointed out that the oxides are pentoxides, 

 Nbj,Oj and Ta^Oj, whilst the niobium chloride and oxy- 

 chloride are represented respectively by the formulae NbCl^ 

 andNbOClj. 



All the other supposed metals turned out to be either 

 simple mixtures of these two in varying proportions, or 



