X PEEFACE. 



should in any case, after perusal by him, have been committed 

 to the flames. In comparison with this rich and piquant col- 

 lection, the small work which came out the same year (1860) 

 entitled ' Letters from Alexander von Humboldt to a Young- 

 Friend, with Notes of Conversations between the Years 1848 

 and 1856,' appeared insignificant, and excited but little atten- 

 tion. Many years passed before the scientific aspect of Hum- 

 boldt's life was again brought into prominence, through the 

 publication of other letters those, for instance, which were 

 edited by H. Berghaus and De la Koquette. Meanwhile, the 

 history of the years 1864 and 1866 drew the attention of 

 Grermany to that political stage where Prussia, the once in- 

 significant country of Humboldt, was now to take the lead, 

 and it was only on the approach of the centenary of his birth 

 that the interest once felt towards him was reawakened. 



At the meeting of the scientific association at Dresden on 

 September 18, 1868, it devolved upon me to make a few in- 

 troductory remarks upon the progress of science, especially 

 with reference to astronomy, in the course of which I made 

 some allusion to the approaching centenary of Humboldt's 

 birth. I availed myself of the opportunity to point out the 

 need of an adequate biography of our distinguished country- 

 man, the want of which was the more to be regretted as the 

 number of those who enjoyed ptftsonal intercourse with him 

 and retained the most vivid recollection of his peculiar charac- 

 teristics was every year diminishing. 



Since that period several fresh sources of information have 

 been thrown open to the compiler of such a work. In the 

 course of the year 1868 a valuable collection of letters from 

 Humboldt to Marie Auguste Pictet made their appearance in 

 the geographical organ ' Le Globe,' constituting the seventh 

 volume of that periodical, which were followed in the succeed- 

 ing year, 1869, by the publication of the ' Correspondence 

 between Alexander von Humboldt and Count Greorge von 

 Cancrin,' and of the exceedingly interesting ' Letters of Hum- 



