PBEFACE. 



WHEN, on May 6, 1859, Alexander von Humboldt closed his 

 eyes in death, in the ninetieth year of his age, the numerous 

 eulogies, biographical notices, and sketches of character that 

 appeared in periodicals of every description, both in his own 

 country and in foreign lands, afforded striking evidence of the 

 universal recognition of his genius, and of the unanimous 

 acknowledgment of the influence he had exerted on the 

 advancement of science during the present century. 



Many attempts have already been made to record the life of 

 this illustrious man, and trace the process of development of 

 his master mind. A skeleton biography was furnished by 

 Humboldt, in the year 1850, at the request of the editor, for 

 Brockhaus' 6 Conversations-Lexikon.' An abridgment of this 

 biography appeared in the tenth edition of that work, while 

 the original article was published entire in the eighth volume 

 of the periodical entitled c Die Gregenwart ' (1853). A bio- 

 graphical memoir, compiled, however, with no direct references 

 to authorities, nor even with much acquaintance with scientific 

 subjects, was brought out by H. Klencke in 1851, and in 1859 

 W. F. A. Zimmermann published his '< Humboldtbuch.' In 

 addition, fragmentary portions of his biography have appeared 

 in various forms. But nowhere has the indefatigable Student 

 of Nature been depicted in the daily routine of his investiga- 



