SMITH— COLUMBIUM AND TANTALUM. 151 



[Contribution from the John Harrison Laboratory of Chemistry.] 



OBSERVATIONS ON COLUMBIUM AND TANTALUM. 

 BY EDGAR F. SMITH. 



{Read April 13, 1905. ) 



In 1 So 1 Hatchett, while studying minerals in the British Mu- 

 seum came upon a specimen from Haddam, Conn., which attracted 

 his attention because of its rather high specific gravity and its bril- 

 liant black color. A portion of this material was given him for ex- 

 amination, with the result that he discovered in it a new metallic 

 acid, to the metal of which he applied the name columbium. It 

 was his earnest hope that he might obtain larger quantities of the 

 American mineral in order to exhaustively study the new element, 

 and it is of interest to remark that Hatchett fondly expected this 

 material assistance from Thomas Peters Smith, a member of this So- 

 ciety and an enthusiast in chemical science, who on his return from 

 England met an untimely death on shipboard. 



In 1802 Ekeberg, of Sweden, while examining an unknown min- 

 eral, found that it contained a new metallic acid, to the metal of 

 which acid he assigned the name tantalum, because "when placed 

 in the midst of acids it is incapable of taking any of them up and 

 saturating itself with them." Later, Wollaston (1809) strove to 

 prove that columbium and tantalum were identical. In this he 

 failed. The few reactions known even at that early day differ- 

 entiated the new elements. About 1840, Heinrich Rose, in study- 

 ing similar minerals, from other localities, came to the conclusion 

 that the American mineral contained an element absolutely differ- 

 ent from tantalum, and called it niobium. Subsequently, owing 

 to his inability to account for the peculiar products which he got 

 by chlorinating a mixture of the oxide of the new element and car- 

 bon, he asserted that, in addition to niobium, there was present 

 pelopium (1846). Later (1853), however, he seems to have ar- 

 rived at the opinion that niobic acid and pelopic acid were differ- 

 ent oxides of niobium. The first he called niobic acid and the 

 second hyponiobic acid. Hermann, also, contributed to the un- 

 certainty which surrounded the two elements (columbium of Hat- 



