PREFACE. 



The following "Index to the Literature of Columbium" has been pub- 

 lished upon the recommendation of the Committee on Indexing Chemical 

 Literature, of the American Association for the Advancement of Science. 

 In its original draft the word " niobium " was used in place of " columbium ; " 

 but upon suggestion from members of the Committee the author consented 

 to a change. It is well known that the name columbium, originally given 

 by Hatchett, has clear priority; while "niobium," and its supposed twin 

 "pelopium," grew out of errors made by Rose, Although in European 

 treatises the name "niobium" has generally been adopted, no good reason 

 for the substitution has ever been offered, and all the accepted rules of 

 nomenclature demand the retention of columbium. This note has been 

 written at the request of Professor Traphagen. 



F. W. Clarke. 



(iii) 



