... Balke and Smith3 obtained large quantities of potassium oxyfluocolum- bate, K,CbOF,, from American columbites. ... OF' CHEMISTRY.] THE ARC SPECTRUM OF COLUMBIUM. BY JOEL w. HILDEBRAXD Received August 15. 1908. ... Letpztg< rgoq, THIS JOURNAL, 30 (1908).