443 Brown Lead Ore of Zimapan. 



to use very plain words, to he up to every thing, and to be quite 

 au fait, respecting the experiments of Vauquelin and Descotils, 

 concerning the metallic nature and properties of chrome. He 

 found Del Rio far removed from Europe, almost without any 

 kindred minds to assist or encourage him, diffident as his charac- 

 ter always has been, and disposed, by many prepossessions, to 

 pay much deference to the opinions of Humboldt. To him Del Rio 

 communicated his discovery, and gave him a copy in the French 

 language, of his experiments, as they were subsequently pub- 

 lished in his translation of Kersten. Humboldt, however, in- 

 formed him that chrome gave by evaporation, red and yellow 

 salts, and induced him to suppose that the phenomena he had 

 observed, were due to the action of chromic acid. Confiding in 

 the superior information of his friend, he accordingly, with 

 great modesty, forbore to press his own opinions ; and in 1804, 

 in his translation of Kersten, submitted that it should be thought 

 a sub-chromate of lead. Descotils himself, sometime after, ex- 

 pressed the same opinion ; a circumstance which took from Del 

 Rio every inducement to revive the subject, which remained 

 buried in error, until Sefstrom discovered the same substance, 

 in 1830, in iron, in Sweden. Mr. Johnston discovered it in 

 Scotland, in the winter of the same year. In the meantime, sub- 

 sequent to Sefstrom's discovery, Wohler re-examined the brown 

 lead ore of Zimapan, and found that it was not a sub-chromate, 

 but that it contained a new metal ; that Del Rio had been per- 

 fectly right from the first, and that Sefstrom had merely repro- 

 duced in 1830, what Del Rio had discovered in 1801. 



Now we would contend, that under these circumstances, any 

 man w^ho attempts to wrest this trophy from Del Rio, is alto- 

 gether unjust, and that he alone is entitled to wear it. In mat- 

 ters of this kind, the motto " qui meruit, ferat," is of universal 

 application. It certainly cannot be asserted by European 

 chemists, that Del Rio is not entitled to the honours of his own 

 discovery, because he has not done all he might have done, to 

 vindicate his own claim to them. The fair way of considering 

 the matter, is, that his discovery would never have been dis- 

 puted, if Baron Humboldt, coming to America as a sort of legate 

 in partibus, on the part of European science, had not misled 

 him, whose only fault has been a diffidence in his own superior 

 attainments. Baron Humboldt, of whom we always wish to 



