THE ATOMIC WEIGHT OF VANADIUM DETERMINED 



FROM THE LABORATORY WORK OF 



EIGHTY YEARS. 



Bv DR. GUSTAVUS D. HIXRICHS. 

 {Read April 21, 1911.) 



\'anadium can no longer be considered a rare element. Ferro- 

 vanadium is produced on a large scale for the manufacture of special 

 vanadium steels. Strangely enough, it was in a kind of natural 

 vanadium iron that Sefstrom detected this element eighty years ago. 



In 1830, while technical director of the famous iron works at 

 Taberg in Smaland, Sweden, Sefstrom thought it might be interest- 

 ing to submit his high quality malleable iron to the Rieman Test 

 for cold-short iron, notwithstanding the apparent absurdity of such 

 an undertaking. Accordingly he took one of his bars. On a part 

 of its bright metallic surface he drew the little circular ridge of 

 tallow and poured dilute sulphuric acid into the shallow dish thus 

 formed, expecting, of course, to see no change whatever of the 

 bright metallic bottom of this improvised dish. But he was 

 amazed to see that bright bottom instantly turn black while the 

 shallow dish rapidly filled up with a black powder, exactly as it 

 does when the iron tested is badly cold-short. 



The distinguished disciple of the great Berzelius instantly realized 

 that this striking contradiction between test and fact was a positive 

 indication of the presence of a hitherto unknown chemical element. 

 Accordingly he set about isolating this new element. Working up 

 quite a number of pounds of his iron, Sefstrom obtained less than a 

 decigramme of the substance from which the new element was to 

 be separated. Hence he turned hopefully from the iron to its fresh 

 slag and found it to yield a much larger per cent, of the black 

 powder. He now soon succeeded in isolating the new element 



191 



