COLUMBIUM. 247 



group ought to lie between indium and tin. The latter 

 triad should have atomic weights ranging from 114 to 117 ; 

 and here possibly, or else forming a triad with yttrium, the 

 other metals of this group may lie. 



COLUMBIUM. 



The atomic weight of this metal has been determined by 

 Rose, Hermann, Blomstrand, and Marignac. Rosef anal- 

 yzed a compound which he supposed to be chloride, but 

 which, according to Rammelsberg,^ must have been nearly 

 pure oxychloride. If it was chloride, then. the widely vary- 

 ing results give approximately Cb = 122 ; if it was oxy- 

 chloride, the value becomes nearly 94. If it was chloride, 

 it was doubtless contaminated with tantalum compounds. 



Hermann's II results seem to have no present value, and 

 as for Blomstrand's,§ I am not able to get at a copy of his 

 original memoir. The results of the latter chemist are thus 

 summed up in Becker's " Digest." Three chlorine estima- 

 tions in the pentachloride give, in mean, Cb = 96.67. 

 Eleven weighings of columbic acid from the same com- 

 pound make Cb = 96.16. Other experiments on sodium 

 columbate lead Blomstrand to regard 95 as the most prob- 

 able value. 



Marignac 1 made about twenty analyses of the potassium 

 fluoxycolumbate, CbOF3.2KF.H,0. 100 parts of this salt 

 give the following percentages : 



Cb^Oj Extremes 44.15 to 44.60 Mean, 44.36 



KjSO^ " 57.60 " 58.05 



■ up " 5.75 " 5.98 



F " 30.62 " 32.22 



* This name has priority over the more generally accepted "niobium," and 

 therefore deserves preference. 



t Poggend. Annal., 104, 439. 1858. 

 -t Poggend. Annal., 136, 353. 1869. 

 II Journ. fur Prakt. Chem., 68, 73. 1856. 

 g Acta Univ. Lund,>i864. 

 ^ Archives des Sci. Phys. et Nat.. (2,) 23, 258. 1865. 



