" age ee 
Prof. Agassiz’s Eulogy on Humboldt. 101 
together before. But here we meet with a singular circ ce. 
The German nobleman, the friend of the Prussian and Spanish 
Courts, chooses Paris for his residence, and remains there twenty- 
two years to work out the result of his scientific labor; for since 
his return, with the exception of short journeys to Italy, Eng- 
land and Germany, sometimes accompanying the King of Prus- 
sia, sometimes alone, or accompanied by scientific friends, he is 
entirely occupied in scientific labors and studies. So passes the 
time to the year 1827, and no doubt he was induced to make this 
choice of a residence by the extraordinary concourse of distin- 
guished men in all branches of science with whom he thought 
he could best discuss the results of his own observations. I 
shall presently have something to say about the works he com- 
pleted during that most laborious period of his life. I will only 
add now, that in 1827 he verre to Berlin permanently, hav- 
ing been urged of late by the King of Prussia again and again 
to return to his native land. And there he delivered a series of 
lectures preparatory to the publication of Cosmos; for in sub- 
stance, even in form and arrangement, these lectures, of which 
the papers of the day gave short accounts, are a sort of prologue 
to the Cosmos, and a preparation for its publication. 
In 1829, when he was 60 years of age, he undertakes another 
great journey. He accepts the invitation of the Emperor Nicho- 
as to visit the Ural Mountains, with a view of examining the 
gold mines and localities where platina and diamonds ha 
found, to determine their geological relations. He accomplished 
the journey with Ehrenberg and Gustavus Rose, who published 
the result of their mineralogical and geological survey in a work 
of which is the sole author; while boldt published 
under the title of Asiatic Fragments of Geology and Climatolo- 
gy, his observations of the physical and geographical features 
made during that journey. But he had hardly returned to Ber- 
lin, when in consequence of the revolution of 1830, he was sent 
by the King of Prussia as extraordinary ambassador to France, 
to honor the elevation of Louis Philippe to the throne. Hum- 
boldt had long been a personal friend of the Orleans family, and 
he was selected as ambassador on that occasion on account of 
these personal relations. From 1830 to 1848 he lived alternate- 
ly in Berlin and in Paris, spending nearly half the time in Paris 
and half the time in Berlin, with occasional visits to England 
and Denmark; publishing the results of his investigations in 
Asia, making original investigations upon various things, an 
especially pressing the establishment of magnetic observatories, 
and connected observations all over the globe, for which he ob- 
