Broivn Lead Ore of Zimapan. 441 



The name of this metal is derived from that of Vanadis, a Scandinavian divin- 

 ity. It is not yet known under what form, or in what state of combination, 

 vanadium occurs in the ore of Jaberg. It is also found in Mexico, in a lead 

 mine at Ziinapan. Del Rio, who analysed it in 1801, announced the dis- 

 covery of a new metal in it, which he called Erythronium ; but the same 

 mineral having soon afterwards been analysed by Collet Descotils, he as- 

 serted that Erythronium was merely impure chromium. Del Rio himself 

 adopted the opinion of the French chemist, and considered the mineral as a 

 subchromate of lead; thus the metal, so near being discovered, remamed 

 thirty years unknown to chemists. Since the discovery of Yanadmm by 

 Seftstr6m, Wohler has ascertained that the mineral of Zimapan contams 

 vanadic and not chromic acid." 



Our readers will observe, that in both these passages Del 

 Rio's prior discovery of the new metal is admitted. Yet Ber- 

 zelius, who says expressly, " Del Rio, who analysed this mineral in 

 1801, amiounced the discovery of a new metal in it," most mcon- 

 sistently asserts that " Vanadium was discovered, in the year 1830, 

 by Sefstromr Mr. Johnston, who no doubt is disposed to be just, 

 appears to have written without proper information respecting 

 the history of this metal ; for he says, that it " has been dis- 

 covered in three different countries nearly at the same time;" 

 and further on, speaking of Del Rio's discovery, he says « his 

 results were not published." Words have very absorbent powers, 

 and time and space will have very little chance with them, if 

 " nearly at the same time" can shut up, like an opera glass, all the 

 interval between 1801 and 1830. As to the non-publication of 

 Del Rio's results, we refer Mr. Johnston to this eminent chemist's 

 translation of Kersten's Mineralogical Tables, p. 61, printed 

 at Mexico, 1804, where he will find the original of the passage 

 of which Professor Del Rio has sent us an English translation, 

 with the preceding communication. 



We proceed now to state why Del Rio was induced to assent 

 to the opinion of Descotils, and apparently to abandon his dis- 

 covery. 



He"^ had, as Berzelius truly says, made the discovery of this 

 new metal, previous to the arrival of Humboldt in Mexico, in 

 1803. They had been fellow students together at Freyberg, 

 in Saxony, at the great school of Werner, where some of the 

 most celebrated analysts acquired the first rudiments of minera- 

 logical knowledge. Humboldt's arrival in Mexico was preceded 

 by the brilliant reputation he had acquired. He was considered. 



Vol. I.— 56 



