156 SMITH— COLUMBIUM AND TANTALUM. LApm .3. 



maun, in his communication of 1877, this acid should be neptunic 

 acid. Therefore, the acid mother liquor was treated as directed 

 by Hermann; namely, it was evaporated, the- residue was dissolved 

 in water and the boiling solution precipitated with an excess of 

 caustic soda. The precipitate, after the liquid had become cold, 

 was filtered out, pressed thoroughly from adherent water and then 

 boiled with 25 times its own weight of pure water. Everything 

 dissolved. The solution was perfectly clear. On cooling, there 

 separated from it the beautiful needle-like crystals of sodium colum- 

 bate. According to Hermann, the precipitate which was collected, 

 pressed out and then boiled with water, should, if neptunium were 

 present, have left a slimy mass, insoluble in water. This, Her- 

 mann said, was sodium neptunate. It should be observed that our 

 experiments were made with the final acid liquors obtained from 

 the double fluorides present in columbite from Haddam ; further, 

 that we proceeded in strict accordance with the directions of Her- 

 mann and having done all this, did not obtain a gelatinous mass 

 which might have been sodium neptunate. In Hermann's com- 

 munication, to which reference has been made so frequently, he 

 lays great stress on the fact that the distinguishing reaction of 

 neptunium is the beautiful golden yellow color which sodium nep- 

 tunate imparts to a salt of phosphorus bead in the reducing flame. 

 It is needless to add that we tried on different occasions to find 

 neptunium, according to the directions of Hermann ; but our 

 search was fruitless. On one occasion, however, we obtained a 

 mass, not great in amount, which, in the inner blow-pipe flame, 

 did impart a yellow color to the salt of phosphorus bead, but more 

 careful examination of this residue demonstrated that it contained 

 tantalum, iron and some columbium. The intense golden yellow 

 color, which was so strongly emphasized by Herman, we could not 

 get ; so that it is very probable that neptunium, like ilmenium and 

 the other metals announced from time to time as present with 

 columbium and tantalum must really be placed in the list of defunct 

 elements. It has not been our wish to bury this candidate for 

 elemental honors. Indeed, we would have been only too glad to 

 have found the evidences of its existence and to have confirmed the 

 observation of that earnest and sincere student of chemical science, 

 who, in his tireless labors, frequently felt confident that he had 

 fallen upon the cause of the varying results observed with colum- 

 bium and tantalum. 



